Editing Glycogen storage disease

{{Infobox medical condition (new)
| name = Glycogen storage disease
| synonyms = Glycogenosis; dextrinosis
| image = Glycogen storage disorder (PAS with diastase).jpg
| image_size =
| caption = Glycogen storage disease in [[hepatocyte]]s
| specialty = [[neuromuscular medicine]]; [[hepatology]]; [[medical genetics]]
| symptoms = Biopsy shows either abnormal accumulation or deficit of glycogen
| complications =
| onset =
| duration =
| types =
| causes = Genetic
| risks =
| diagnosis =
| differential =
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| prognosis =
| frequency =
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}}

A '''glycogen storage disease''' ('''GSD''', also '''glycogenosis''' and '''dextrinosis''') is a [[metabolic disorder]] caused by a deficiency of an [[enzyme]] or [[transport protein]] affecting [[glycogen synthesis]], [[glycogen breakdown]], or [[glycolysis|glucose breakdown]], typically in [[muscle]]s and/or [[liver]] cells.<ref>{{cite journal |doi=10.3233/NPM-1831|pmid=30741698|title=Glucose-6-Phosphate dehydrogenase deficiency incidence in a Hispanic population|journal=Journal of Neonatal-Perinatal Medicine|pages=203–207|year=2019|last1=Cantú-Reyna|first1=C.|last2=Santos-Guzmán|first2=J.|last3=Cruz-Camino|first3=H.|last4=Vazquez Cantu|first4=D.L.|last5=Góngora-Cortéz|first5=J.J.|last6=Gutiérrez-Castillo|first6=A.|volume=12|issue=2|s2cid=73452760}}</ref>

GSD has two classes of cause: genetic and environmental. Genetic GSD is caused by any [[Inborn errors of carbohydrate metabolism|inborn error of carbohydrate metabolism]] (genetically defective enzymes or transport proteins) involved in these processes.  In livestock, environmental GSD is caused by [[Substance intoxication|intoxication]] with the [[alkaloid]] [[castanospermine]].<ref name="pmid7604496">{{cite journal|vauthors=Stegelmeier BL, Molyneux RJ, Elbein AD, James LF|date=May 1995|title=The lesions of locoweed (Astragalus mollissimus), swainsonine, and castanospermine in rats|journal=Veterinary Pathology|volume=32|issue=3|pages=289–98|doi=10.1177/030098589503200311|pmid=7604496|s2cid=45016726|doi-access=free}}</ref>

However, not every inborn error of carbohydrate metabolism has been assigned a GSD number, even if it is known to affect the muscles or liver. For example, [[phosphoglycerate kinase deficiency]] (gene PGK1) has a myopathic form.

Also, [[Fanconi–Bickel syndrome|Fanconi-Bickel syndrome]] (gene SLC2A2) and [[Danon disease]] (gene LAMP2) were declassed as GSDs due to being defects of [[transport protein]]s rather than [[enzyme]]s; however, [[Glycogen storage disease type I|GSD-1]] subtypes b, c, and d are due to defects of transport proteins (genes SLC37A4, SLC17A3) yet are still considered GSDs.

[[Phosphoglucomutase|Phosphoglucomutase deficiency]] (gene PGM1) was declassed as a GSD due to it also affecting the formation of N-glycans; however, as it affects both [[glycogenolysis]] and [[glycosylation]], it has been suggested that it should re-designated as GSD-XIV.<ref name="nejm.org">{{Cite journal |last1=Stojkovic |first1=Tanya |last2=Vissing |first2=John |last3=Petit |first3=François |last4=Piraud |first4=Monique |last5=Orngreen |first5=Mette C. |last6=Andersen |first6=Grete |last7=Claeys |first7=Kristl G. |last8=Wary |first8=Claire |last9=Hogrel |first9=Jean-Yves |last10=Laforêt |first10=Pascal |date=2009-07-23 |title=Muscle Glycogenosis Due to Phosphoglucomutase 1 Deficiency |journal=New England Journal of Medicine |language=en |volume=361 |issue=4 |pages=425–427 |doi=10.1056/NEJMc0901158 |pmid=19625727 |issn=0028-4793|doi-access=free }}</ref>

''(See [[inborn errors of carbohydrate metabolism]] for a full list of inherited diseases that affect glycogen synthesis, glycogen breakdown, or glucose breakdown.)''

==Types==
{{clear}}
{| class="wikitable"
 ! Type<br />(Eponym)
 ! Enzyme deficiency<br />(Gene<ref name="medbiochem"/>)
 ! Incidence (births)
 ! [[Hypoglycemia|Hypo-<br />glycemia]]?
 ! [[Hepatomegaly|Hepato-<br />megaly]]?
 ! [[Hyperlipidemia|Hyper-<br />lipidemia]]?
 ! Muscle symptoms
 ! Development/ prognosis
 ! Other symptoms
 |-
 | [[Glycogen storage disease type 0|GSD 0]]
(Lewis' disease)<ref>{{Cite web |title=Glycogen Storage Diseases |url=https://my.clevelandclinic.org/health/diseases/15553-glycogen-storage-disease-gsd |access-date=2023-12-29 |website=Cleveland Clinic |language=en}}</ref>
 | [[Glycogen synthase]] <br />(Muscle [[Glycogen synthase|GYS1]] / Liver [[GYS2]])
 | 1 in 20,000–25,000<ref>{{Cite journal |date=2022-10-10 |title=Glycogen-Storage Disease Type 0 (GSD-0) (Glycogen Synthetase Deficiency): Background, Pathophysiology, Epidemiology |url=https://emedicine.medscape.com/article/944467-overview}}</ref>
 | Liver 0a: Yes
Muscle 0b: No
 | No
 | No
 | (Muscle 0b) Glycogen deficiency in muscle fibres. Type I muscle fibre predominance. Exercise-induced, muscle fatigue, myalgia, fainting.<ref name=":26">{{Cite web |title=GLYCOGEN STORAGE DISEASE 0, MUSCLE; GSD0B |url=https://www.omim.org/entry/611556 |access-date=2023-12-29 |website=www.omim.org |language=en-us}}</ref><ref name=":25">{{Cite web |title=Glycogen Storage Disease type 0 |url=https://medlineplus.gov/download/genetics/condition/glycogen-storage-disease-type-0.pdf |website=MedLine Plus}}</ref> Occasional [[muscle cramp]]ing {{citation needed|date=December 2023}}
 | (Liver 0a) Growth failure in some cases.<ref name=":27" />
(Muscle 0b) Risk of sudden death in childhood due to cardiac arrest.<ref name=":26" />
 |
(Liver 0a) Epilepsy<ref name=":27">{{Cite web |title=GLYCOGEN STORAGE DISEASE 0, LIVER; GSD0A |url=https://www.omim.org/entry/240600 |access-date=2023-12-29 |website=www.omim.org |language=en-us}}</ref>

(Muscle 0b) Rarely epilepsy, tonic-clonic seizures.<ref name=":26" /> Arrhythmia, long QT syndrome.<ref name=":25" />
|-
 | [[Glycogen storage disease type I|GSD I]] / GSD 1 <br />([[von Gierke's disease]])
 | [[Glucose-6-phosphatase]] / [[Glucose-6-phosphate translocase]]  <br />([[G6PC]] / [[SLC37A4]] /[[SLC17A3]])
 | {{ntsh|75000}}1 in 50,000&nbsp;– 100,000<ref name=Roth/><ref>{{cite web|url=http://www.agsdus.org/type-i.php|publisher=Association for Glycogen Storage Diseases (AGSD)|title=Glycogen Storage Disease Type I|date=October 2006|archive-url=https://web.archive.org/web/20210411204929/https://agsdus.org/type-i.php|archive-date=11 April 2021}}</ref><ref name="Glucose-6-Phosphate dehydrogenase d">{{cite journal|last1=Cantú-Reyna |first1=C.|last2=Santos-Guzmán|first2=J.|last3=Cruz-Camino |first3=H.|last4=.Vazquez Cantu |first4=D.L.|last5=Góngora-Cortéz |first5=J.J. |last6=Gutiérrez-Castillo |first6=A.|url=https://content.iospress.com/articles/journal-of-neonatal-perinatal-medicine/npm1831|title=Glucose-6-Phosphate dehydrogenase deficiency incidence in a Hispanic population |journal=Journal of Neonatal-Perinatal Medicine |date=4 February 2019|volume=12 |issue=2|pages=203–207|doi=10.3233/NPM-1831|pmid=30741698 |s2cid=73452760}}</ref>
 | Yes
 | Yes
 | Yes
 | None
 | [[Growth failure]]
 | [[Lactic acidosis]], [[hyperuricemia]]
 |-
 | [[Glycogen storage disease type II|GSD II]] / GSD 2 <br />([[Pompe disease]], formerly GSD-IIa)
----[[Danon disease]] (formerly GSD-IIb)
 | [[Acid alpha-glucosidase]]
([[Acid alpha-glucosidase|GAA]])
----[[LAMP2|Lysosome-associated membrane protein 2]]<br />([[LAMP2]])
 | {{ntsh|13000}}Pompe disease is 1 in 13,000.<ref>{{Cite journal|doi=10.1542/peds.2016-0280C|title=Newborn Screening for Pompe Disease|year=2017|last1=Bodamer|first1=Olaf A.|last2=Scott|first2=C. Ronald|last3=Giugliani|first3=Roberto|author4=Pompe Disease Newborn Screening Working Group|journal=Pediatrics|volume=140|issue=Suppl 1|pages=S4–S13|pmid=29162673|s2cid=43782810|doi-access=free}}</ref>
 | No
 | Yes
 | No
 | [[Muscle weakness]], [[exercise intolerance]], abnormal lysosomal glycogen accumulation in muscle biopsy. Late-onset Pompe may have a [[pseudoathletic appearance]] of hypertrophic calf muscles.<ref name=":18">{{Cite journal |last1=Menon |first1=M. Suraj |last2=Roopch |first2=P. Sreedharan |last3=Kabeer |first3=K. Abdulkhayar |last4=Shaji |first4=C. Velayudhan |date=July 2016 |title=Calf Muscle Hypertrophy in Late Onset Pompe's Disease |journal=Archives of Medicine and Health Sciences |language=en-US |volume=4 |issue=2 |pages=251 |doi=10.4103/2321-4848.196188 |issn=2321-4848 |s2cid=58424073 |doi-access=free}}</ref>
The symptoms of both Pompe and Danon diseases are very similar due to a defect in lysosomes. However, in Danon disease, some show abnormal glycogen accumulation, but not all.<ref>{{Cite web |date=3 June 1986 |title=OMIM - # 300257 DANON DISEASE |url=https://www.omim.org/entry/300257 |website=OMIM&nbsp;— Online Medelian Inheritance in Man}}</ref>
 | Progressive proximal skeletal muscle weakness with varied timeline to threshold of functional limitation (early childhood to adulthood). Approximately 15% of the Pompe population is classified as infantile Pompe which is typically deadly within the first year if untreated.
 | [[Heart failure]] (infantile), respiratory difficulty (due to muscle weakness)
 |-
 | [[Glycogen storage disease type III|GSD III]] / GSD 3 <br />([[Cori's disease]] or [[Forbes' disease]])
 | [[Glycogen debranching enzyme]]<br />([https://www.genenames.org/cgi-bin/gene_symbol_report?hgnc_id=321 AGL] {{Webarchive|url=https://web.archive.org/web/20171204222946/https://www.genenames.org/cgi-bin/gene_symbol_report?hgnc_id=321 |date=2017-12-04 }})
 | {{ntsh|100000}}1 in 100,000
 | Yes
 | Yes
 | Yes
 | Myopathy. May have a [[pseudoathletic appearance]] of hypertrophic muscles.<ref name=":8" />
 |[[Failure to thrive]]<ref name="Tegay 2022 m937">{{cite journal | last=Tegay | first=David H | title=Genetics of Glycogen-Storage Disease Type III Clinical Presentation: History, Physical, Causes | website=Medscape Reference | date=March 15, 2022 |url=https://emedicine.medscape.com/article/942618-clinical#showall | access-date=October 24, 2023}}</ref>
 |
myogenic [[hyperuricemia]]<ref name=":0">Mineo I, Kono N, Hara N, Shimizu T, Yamada Y, Kawachi M, Kiyokawa H, Wang YL, Tarui S. Myogenic hyperuricemia. A common pathophysiologic feature of glycogenosis types III, V, and VII. N Engl J Med. 1987 Jul 9;317(2):75-80. doi: 10.1056/NEJM198707093170203. [//www.ncbi.nlm.nih.gov/pubmed/3473284?dopt=Abstract PMID 3473284].</ref>
|-
 | [[Glycogen storage disease type IV|GSD IV]] / GSD 4<br />([[Andersen's disease]])
 | [[Glycogen branching enzyme]]<br />([[GBE1]])
 | {{ntsh|500000}}1 in 500,000<ref name="ceaccp.oxfordjournals.org">{{Cite journal |doi = 10.1093/bjaceaccp/mkq055|title = Perioperative care of children with inherited metabolic disorders|journal = Continuing Education in Anaesthesia, Critical Care & Pain|volume = 11|issue = 2|pages = 62–68|year = 2011|last1 = Stuart|first1 = Grant|last2 = Ahmad|first2 = Nargis|doi-access = free}}</ref>
 | No
 | Yes,<br />also<br /> [[cirrhosis]]
 | No
 | Myopathy and dilated cardiomyopathy
 | [[Failure to thrive]], death at age ~5 years
 |
 |-
 | [[Glycogen storage disease type V|GSD V]] / GSD 5<br />([[McArdle's disease]])
 | [[Muscle glycogen phosphorylase]]<br />([[Myophosphorylase|PYGM]])
 | {{ntsh|250000}}1 in 100,000&nbsp;– 500,000<ref>{{cite book|last1=Khattak|first1=Zoia E.|title=McArdle Disease|date=January 2022|url=http://www.ncbi.nlm.nih.gov/books/NBK560785/|work=StatPearls|place=Treasure Island, Florida (FL)|url-status=live|archive-url=https://web.archive.org/web/20220427180218/http://www.ncbi.nlm.nih.gov/books/NBK560785/|archive-date=27 April 2022|publisher=[[StatPearls Publishing]]|pmid=32809620|access-date=7 July 2022|last2=Ashraf|first2=Muddasir}}</ref><ref name="ceaccp.oxfordjournals.org"/>
 | No
 | No
 | No
 |Exercise-induced muscle fatigue and cramps. [[Rhabdomyolysis]] possible. May have a [[pseudoathletic appearance]] of hypertrophic calf muscles.<ref name=":11">{{Cite journal |last1=Rodríguez-Gómez |first1=I. |last2=Santalla |first2=A. |last3=Díez-Bermejo |first3=J. |last4=Munguía-Izquierdo |first4=D. |last5=Alegre |first5=L. M. |last6=Nogales-Gadea |first6=G. |last7=Arenas |first7=J. |last8=Martín |first8=M. A. |last9=Lucía |first9=A. |last10=Ara |first10=I. |date=November 2018 |title=Non-osteogenic muscle hypertrophy in children with McArdle disease |url=https://pubmed.ncbi.nlm.nih.gov/29594644/ |journal=Journal of Inherited Metabolic Disease |volume=41 |issue=6 |pages=1037–1042 |doi=10.1007/s10545-018-0170-7 |issn=1573-2665 |pmid=29594644|hdl=10578/19657 |s2cid=4394513 |hdl-access=free }}</ref>
 |
 | [[Renal failure]] by [[myoglobinuria]], [[second wind phenomenon]], inappropriate rapid heart rate ([[sinus tachycardia]]) response to exercise, myogenic [[hyperuricemia]]<ref name=":0" />
 |-
 | [[Glycogen storage disease type VI|GSD VI]] / GSD 6 <br />([[Hers' disease]])
 | [[Liver glycogen phosphorylase]] <br />([[PYGL]])
 | {{ntsh|75000}}1 in 65,000&nbsp;– 85,000<ref name="Ierardi-Curto">{{cite news|url=http://emedicine.medscape.com/article/950587-overview|title=Genetics of Glycogen Storage Disease Type VI (Hers Disease)|publisher=[[eMedicine]] (Medscape Reference)|first1=Anna V.|last1=Blenda|first2=Renee J.|last2=Chosed|first3=Mary L.|last3=Windle|first5=Lynne I
|last5=Curto|first4=Maria|last4=Descartes|first6=Edward|last6=Kaye|date=4 Aug 2008|archive-url=https://web.archive.org/web/20220101134503/https://emedicine.medscape.com/article/950587-overview|archive-date=1 January 2022}}</ref>
 | Yes
 | Yes
 | Yes<ref>{{cite book|last1=Goldman|first1=Lee|last2=Schafer|first2=Andrew|title=Goldman's Cecil medicine|year=2012|edition =24th|publisher=Elsevier/Saunders|location=Philadelphia|isbn=978-1-4377-1604-7|page=1356}}</ref>
 |None
 | initially benign, developmental delay follows.
 |
 |-
 | [[Glycogen storage disease type VII|GSD VII]] / GSD 7 <br />([[Tarui's disease]])
 | [[Phosphofructokinase 1|Muscle phosphofructokinase]] <br />([[PFKM]])
 | {{ntsh|1000000}}1 in 1,000,000<ref>{{cite web|title=Rare Disease Database|url=http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=371|website=Orpha.net|access-date=2015-09-20}}</ref>
 | No
 | No
 | No
 |Exercise-induced muscle cramps and weakness
 | [[Developmental disability|developmental delay]]
 | In some [[haemolytic anaemia]],
myogenic [[hyperuricemia]]<ref name=":0" />
 |-
 | [[Glycogen storage disease type IX|GSD IX]] / GSD 9
 | [[Phosphorylase kinase]] <br />([[PHKA2]] / [[PHKB]] / [[PHKG2]] / [[PHKA1]])
 | ?
 | Yes
 | Yes
 | Yes
 | IXd Exercise-induced muscle cramps, stiffness, weakness (fatigue), and pain.<ref>{{Cite web |title=GLYCOGEN STORAGE DISEASE IXd; GSD9D |url=https://www.omim.org/entry/300559 |access-date=2023-12-29 |website=www.omim.org |language=en-us}}</ref>
 | Liver type: [[Delayed motor development]], [[Developmental disability|Developmental delay]]
 |
 |-
 | [[Glycogen storage disease type X|GSD X]] / GSD 10
 |[[Phosphoglycerate mutase|Muscle Phosphoglycerate mutase]]([https://ghr.nlm.nih.gov/gene/PGAM2 PGAM2])
| ?
 | ?
 | ?
 | ?
 |Exercise-induced muscle cramps and weakness<ref name=":21" />
 |
 |Myoglobinuria<ref>{{Cite web|url=https://ghr.nlm.nih.gov/condition/phosphoglycerate-mutase-deficiency|title=Phosphoglycerate mutase deficiency|last=Reference|first=Genetics Home|website=Genetics Home Reference|language=en|access-date=2019-02-06}}</ref>
 |-
 | [[Glycogen storage disease type XI|GSD XI]] / GSD 11
 | [[lactate dehydrogenase|Muscle lactate dehydrogenase]]<br />([[LDHA]])
 | ?
 | ?
 | ?
 | ?
 |
Exercise-induced muscle cramps, stiffness, pain.<ref>{{Cite web |title=GLYCOGEN STORAGE DISEASE XI; GSD11 |url=https://www.omim.org/entry/612933 |access-date=2023-12-29 |website=www.omim.org |language=en-us}}</ref>
|
 |
 |-
 | [[Fanconi-Bickel syndrome]]<br />formerly [[Glycogen storage disease type XI|GSD XI]] / GSD 11, no longer considered a GSD
 | [[Glucose transporter]]<br />([[GLUT2]])
 | ?
 | Yes
 |

Yes
 | No
 | None
 |
 |
 |-
 | GSD XII / GSD 12<br />{{Nowrap|([[Aldolase A deficiency]])}}
 | [[Aldolase A]]<br />([[ALDOA]])
 | ?
 | No
 | In some
 | No
 | [[Exercise intolerance]], [[cramps]]. In some Rhabdomyolysis.
 |
 | Hemolytic anemia and [[Aldolase A deficiency#Symptoms and signs|other symptoms]]
 |-
 | [[Glycogen storage disease type XIII|GSD XIII]] / GSD 13
 | [[enolase|β-enolase]]<br />([[ENO3]])
 | ?
 | No
 | ?
 | No
 | [[Exercise intolerance]], [[cramps]]
 | Increasing intensity of [[myalgia]]s over decades<ref name="Httpneuromuscularwustledumsysglycogenhtmlenolase">{{Cite web |url=http://neuromuscular.wustl.edu/msys/glycogen.html#enolase | title=Glycogenoses}}</ref>
 | [[Creatine kinase|Serum CK]]: Episodic elevations; Reduced with rest<ref name="Httpneuromuscularwustledumsysglycogenhtmlenolase"/>
|-
|[[Congenital disorder of glycosylation|CDG]]1T (formally GSD XIV / GSD 14)
|[[Phosphoglucomutase|<small>Phosphoglucomutase-1</small>]]([[PGM1]])
|?
|Episodic
|?
|No
|Two forms: exclusively myopathic and multi-system (including muscles).<ref name=":9">{{Cite journal |last1=Altassan |first1=Ruqaiah |last2=Radenkovic |first2=Silvia |last3=Edmondson |first3=Andrew C. |last4=Barone |first4=Rita |last5=Brasil |first5=Sandra |last6=Cechova |first6=Anna |last7=Coman |first7=David |last8=Donoghue |first8=Sarah |last9=Falkenstein |first9=Kristina |last10=Ferreira |first10=Vanessa |last11=Ferreira |first11=Carlos |last12=Fiumara |first12=Agata |last13=Francisco |first13=Rita |last14=Freeze |first14=Hudson |last15=Grunewald |first15=Stephanie |date=January 2021 |title=International consensus guidelines for phosphoglucomutase 1 deficiency (PGM1-CDG): Diagnosis, follow-up, and management |journal=Journal of Inherited Metabolic Disease |volume=44 |issue=1 |pages=148–163 |doi=10.1002/jimd.12286 |issn=0141-8955 |pmc=7855268 |pmid=32681750}}</ref>
Myopathy (including exercise-related fatigue, [[exercise intolerance]], muscle weakness).
Muscle biopsy shows glycogen accumulation.<ref name=":1">{{Cite web |title=Entry - #614921 - CONGENITAL DISORDER OF GLYCOSYLATION, TYPE It; CDG1T&nbsp;— OMIM |url=https://omim.org/entry/614921 |access-date=2023-02-23 |website=omim.org |language=en-us}}</ref>
|Short stature, some have developmental delay, and rarely delayed puberty.<ref name=":1" />
|Highly variable phenotype and severity. Commonly elevated serum CK, abnormal serum transferrin (loss of complete N-glycans), short stature, cleft palate, bifid uvula, and hepatopathy.<ref name=":1" />
[[Second wind|Second Wind]] phenomenon in some<ref name=":10">{{Cite journal |last1=Preisler |first1=Nicolai |last2=Cohen |first2=Jonathan |last3=Vissing |first3=Christoffer Rasmus |last4=Madsen |first4=Karen Lindhardt |last5=Heinicke |first5=Katja |last6=Sharp |first6=Lydia Jane |last7=Phillips |first7=Lauren |last8=Romain |first8=Nadine |last9=Park |first9=Sun Young |last10=Newby |first10=Marta |last11=Wyrick |first11=Phil |last12=Mancias |first12=Pedro |last13=Galbo |first13=Henrik |last14=Vissing |first14=John |last15=Haller |first15=Ronald Gerald |date=November 2017 |title=Impaired glycogen breakdown and synthesis in phosphoglucomutase 1 deficiency |url=https://linkinghub.elsevier.com/retrieve/pii/S1096719217304079 |journal=Molecular Genetics and Metabolism |language=en |volume=122 |issue=3 |pages=117–121 |doi=10.1016/j.ymgme.2017.08.007|pmid=28882528 }}</ref> but not all<ref name="nejm.org"/>
|-
 | [[Glycogen storage disease type XV|GSD XV]] / GSD 15
 | [[Glycogenin-1]]<br />([[GYG1]])
 | Rare<ref name="Malfatti2014">Malfatti E, Nilsson J, Hedberg-Oldfors C, Hernandez-Lain A, Michel F, Dominguez-Gonzalez C, Viennet G, Akman HO, Kornblum C, Van den Bergh P, Romero NB, Engel AG, DiMauro S, Oldfors A (2014) A new muscle glycogen storage disease associated with glycogenin-1 deficiency. Ann Neurol 76(6):891-898
</ref>
 | No
 | No
 | No
 | Muscle atrophy, exercise intolerance, muscle biopsy shows abnormal glycogen depletion and marked proliferation of slow-twitch (type 1/oxidative) muscle fibres and mitochondrial proliferation.
 | Slowly progressive weakness over decades
 | Arrhythmia, biopsy of heart showed abnormal glycogen deposits (different from polyglucosan bodies) in cardiomyocytes.<ref>{{Cite journal |last1=Moslemi |first1=Ali-Reza |last2=Lindberg |first2=Christopher |last3=Nilsson |first3=Johanna |last4=Tajsharghi |first4=Homa |last5=Andersson |first5=Bert |last6=Oldfors |first6=Anders |date=April 2010 |title=Glycogenin-1 Deficiency and Inactivated Priming of Glycogen Synthesis |journal=New England Journal of Medicine |language=en |volume=362 |issue=13 |pages=1203–1210 |doi=10.1056/NEJMoa0900661 |pmid=20357282 |issn=0028-4793|doi-access=free }}</ref>
|}

* Some GSDs have different forms, e.g. infantile, juvenile, adult (late-onset).{{cn|date=October 2024}}
* Some GSDs have different subtypes, e.g. GSD1a / GSD1b, GSD9A1 / GSD9A2 / GSD9B / GSD9C / GSD9D.<ref name="medbiochem"/>
* GSD type 0: Although [[glycogen synthase]] deficiency does not result in storage of extra glycogen in the liver, it is classified with the GSDs as type 0 because it is another defect of glycogen storage and can cause similar problems.{{cn|date=October 2024}}
* GSD type VIII (GSD 8): In the past, liver phosphorylase-b kinase deficiency was considered a distinct condition,<ref name="pmid4508182">{{cite journal |vauthors=Ludwig M, Wolfson S, Rennert O |title=Glycogen storage disease, type 8 |journal=Arch. Dis. Child. |volume=47 |issue=255 |pages=830–833 |date=October 1972 |pmid=4508182 |pmc=1648209 |doi= 10.1136/adc.47.255.830}}</ref> however it has been classified with GSD type VI<ref name="Ierardi-Curto"/> and GSD IXa1;<ref>[https://www.omim.org/entry/306000  GLYCOGEN STORAGE DISEASE IXa1; GSD9A1] OMIM&nbsp;— Online Mendelian Inheritance in Man</ref> it has been described as [[X-linked recessive]] inherited.<ref name="urlDefinition: glycogen storage disease type VIII from Online Medical Dictionary">{{Cite web |url=http://cancerweb.ncl.ac.uk/cgi-bin/omd?glycogen+storage+disease+type+VIII |title=Definition: glycogen storage disease type VIII from Online Medical Dictionary |access-date=2008-09-01 |archive-date=2009-07-03 |archive-url=https://web.archive.org/web/20090703034525/http://cancerweb.ncl.ac.uk/cgi-bin/omd?glycogen+storage+disease+type+VIII |url-status=dead }}</ref> GSD IX has become the dominant classification for this disease, grouped with the other isoenzymes of phosphorylase-b kinase deficiency.<ref>{{Citation |last1=Herbert |first1=Mrudu |title=Phosphorylase Kinase Deficiency |date=1993 |url=http://www.ncbi.nlm.nih.gov/books/NBK55061/ |work=GeneReviews® |editor-last=Adam |editor-first=Margaret P. |place=Seattle (WA) |publisher=University of Washington, Seattle |pmid=21634085 |access-date=2023-02-26 |last2=Goldstein |first2=Jennifer L. |last3=Rehder |first3=Catherine |last4=Austin |first4=Stephanie |last5=Kishnani |first5=Priya S. |last6=Bali |first6=Deeksha S. |editor2-last=Everman |editor2-first=David B. |editor3-last=Mirzaa |editor3-first=Ghayda M. |editor4-last=Pagon |editor4-first=Roberta A.}}</ref>
* GSD type XI (GSD 11): [[Fanconi-Bickel syndrome]] (GLUT2 deficiency), hepatorenal glycogenosis with renal Fanconi syndrome, no longer considered a glycogen storage disease, but a defect of glucose transport.<ref name="medbiochem"/> The designation of GSD type XI (GSD 11) has been repurposed for [[Lactate dehydrogenase#Genetics|muscle lactate dehydrogenase deficiency]] (LDHA).{{cn|date=October 2024}}
* GSD type XIV (GSD 14): No longer classed as a GSD, but as a [[congenital disorder of glycosylation]] type 1T (CDG1T), affects the phosphoglucomutase enzyme (gene PGM1).<ref name="medbiochem">{{Cite web|url=https://themedicalbiochemistrypage.org/glycogen-metabolism/|title=Glycogen Metabolism|website=Themedicalbiochemistrypage.org|date=29 April 2020|access-date=5 July 2022}}</ref> [[Phosphoglucomutase#Disease relevance|Phosphoglucomutase 1 deficiency]] is both a glycogenosis and a congenital disorder of glycosylation.<ref name=":2">{{Cite journal |last1=Tegtmeyer |first1=Laura C. |last2=Rust |first2=Stephan |last3=van Scherpenzeel |first3=Monique |last4=Ng |first4=Bobby G. |last5=Losfeld |first5=Marie-Estelle |last6=Timal |first6=Sharita |last7=Raymond |first7=Kimiyo |last8=He |first8=Ping |last9=Ichikawa |first9=Mie |last10=Veltman |first10=Joris |last11=Huijben |first11=Karin |last12=Shin |first12=Yoon S. |last13=Sharma |first13=Vandana |last14=Adamowicz |first14=Maciej |last15=Lammens |first15=Martin |date=2014-02-06 |title=Multiple Phenotypes in Phosphoglucomutase 1 Deficiency |journal=New England Journal of Medicine |language=en |volume=370 |issue=6 |pages=533–542 |doi=10.1056/NEJMoa1206605 |issn=0028-4793 |pmc=4373661 |pmid=24499211}}</ref> Individuals with the disease have both a glycolytic block as muscle glycogen cannot be broken down, as well as abnormal serum transferrin (loss of complete N-glycans).<ref name=":2" /> As it affects glycogenolysis, it has been suggested that it should re-designated as GSD-XIV.<ref name="nejm.org" />
* [[Lafora disease]] is considered a complex neurodegenerative disease and also a glycogen metabolism disorder.<ref>{{cite journal | pmc=3917365 | date=2014 | last1=Ortolano | first1=S. | last2=Vieitez | first2=I. | last3=Agis-Balboa | first3=R. C. | last4=Spuch | first4=C. | title=Loss of GABAergic cortical neurons underlies the neuropathology of Lafora disease | journal=Molecular Brain | volume=7 | page=7 | doi=10.1186/1756-6606-7-7 | doi-access=free | pmid=24472629 }}</ref>
* Polyglucosan storage myopathies are associated with defective glycogen metabolism<ref>{{cite journal | doi=10.1016/j.mam.2015.08.006 | title=Polyglucosan storage myopathies | date=2015 | last1=Hedberg-Oldfors | first1=Carola | last2=Oldfors | first2=Anders | journal=Molecular Aspects of Medicine | volume=46 | pages=85–100 | pmid=26278982 }}</ref>
* (Not McArdle disease, same gene but different symptoms) Myophosphorylase-a activity impaired: Autosomal dominant mutation on PYGM gene. AMP-independent myophosphorylase activity impaired, whereas the AMP-dependent activity was preserved. No exercise intolerance. Adult-onset muscle weakness. Accumulation of the intermediate filament desmin in the myofibers of the patients.<ref>Echaniz-Laguna A, Lornage X, Laforêt P, Orngreen MC, Edelweiss E, Brochier G, Bui MT, Silva-Rojas R, Birck C, Lannes B, Romero NB, Vissing J, Laporte J, Böhm J. A New Glycogen Storage Disease Caused by a Dominant PYGM Mutation. Ann Neurol. 2020 Aug;88(2):274-282. doi: 10.1002/ana.25771. Epub 2020 Jun 3. [//www.ncbi.nlm.nih.gov/pubmed/32386344?dopt=Abstract PMID 32386344].</ref><ref>{{Cite journal |last1=Echaniz-Laguna |first1=A. |last2=Lornage |first2=X. |last3=Edelweiss |first3=E. |last4=Laforêt |first4=P. |last5=Eymard |first5=B. |last6=Vissing |first6=J. |last7=Laporte |first7=J. |last8=Böhm |first8=J. |date=October 2019 |title=O.5A new glycogen storage disorder caused by a dominant mutation in the glycogen myophosphorylase gene (PYGM) |url=https://linkinghub.elsevier.com/retrieve/pii/S0960896619304110 |journal=Neuromuscular Disorders |language=en |volume=29 |pages=S39 |doi=10.1016/j.nmd.2019.06.023|s2cid=203582211 }}</ref> Myophosphorylase comes in two forms: form 'a' is phosphorylated by phosphorylase kinase, form 'b' is not phosphorylated. Both forms have two [[Conformational change|conformational]] states: active (R or relaxed) and inactive (T or tense). When either form 'a' or 'b' are in the active state, then the enzyme converts glycogen into glucose-1-phosphate. Myophosphorylase-b is allosterically activated by AMP being in larger concentration than ATP and/or glucose-6-phosphate. (See [[Glycogen phosphorylase#Regulation|Glycogen phosphorylase§Regulation]]).
* Unknown glycogenosis related to dystrophy gene deletion: patient has a previously undescribed myopathy associated with both Becker muscular dystrophy and a glycogen storage disorder of unknown aetiology.<ref>Rose MR, Howard RS, Genet SA, McMahon CJ, Whitfield A, Morgan-Hughes JA. A case of myopathy associated with a dystrophin gene deletion and abnormal glycogen storage. Muscle Nerve. 1993 Jan;16(1):57-62. doi: 10.1002/mus.880160110. [//www.ncbi.nlm.nih.gov/pubmed/8423832?dopt=Abstract PMID 8423832].</ref>

== Diagnosis ==
[[Image:Glycogen storage disease in liver - high mag.jpg|thumb|right|[[Micrograph]] of glycogen storage disease with [[histology|histologic]] features consistent with [[Cori disease]]. [[Liver biopsy]]. [[H&E stain]].]]
Methods to diagnose glycogen storage diseases include [[Medical history|history]] and [[physical examination]] for associated symptoms, [[blood test]]s for associated metabolic disturbances, and [[genetic testing]] for suspected mutations.<ref name=":8">{{Cite journal |last1=Kishnani |first1=Priya S. |last2=Austin |first2=Stephanie L. |last3=Arn |first3=Pamela |last4=Bali |first4=Deeksha S. |last5=Boney |first5=Anne |last6=Case |first6=Laura E. |last7=Chung |first7=Wendy K. |last8=Desai |first8=Dev M. |last9=El-Gharbawy |first9=Areeg |last10=Haller |first10=Ronald |last11=Smit |first11=G. Peter A. |last12=Smith |first12=Alastair D. |last13=Hobson-Webb |first13=Lisa D. |last14=Wechsler |first14=Stephanie Burns |last15=Weinstein |first15=David A. |date=July 2010 |title=Glycogen Storage Disease Type III diagnosis and management guidelines |journal=Genetics in Medicine |language=en |volume=12 |issue=7 |pages=446–463 |doi=10.1097/GIM.0b013e3181e655b6 |pmid=20631546 |s2cid=4609175 |issn=1530-0366|doi-access=free }}</ref><ref name=":5" /> It may also include a non-ischemic forearm test, [[exercise stress test]], or 12-minute walk test (12MWT).<ref name=":5">{{Cite journal |last1=Lucia |first1=Alejandro |last2=Martinuzzi |first2=Andrea |last3=Nogales-Gadea |first3=Gisela |last4=Quinlivan |first4=Ros |last5=Reason |first5=Stacey |last6=International Association for Muscle Glycogen Storage Disease study group |date=December 2021 |title=Clinical practice guidelines for glycogen storage disease V & VII (McArdle disease and Tarui disease) from an international study group |journal=Neuromuscular Disorders |volume=31 |issue=12 |pages=1296–1310 |doi=10.1016/j.nmd.2021.10.006 |issn=1873-2364 |pmid=34848128|s2cid=240123241 |doi-access=free }}</ref> Advancements in genetic testing are slowly diminishing the need for biopsy; however, in the event of a [[Variant of uncertain significance|VUS]] and inconclusive exercise tests, a biopsy would then be necessary to confirm diagnosis.<ref name=":5" />

=== Differential diagnosis ===

==== Muscle ====
Glycogen storage diseases that involve skeletal muscle typically have exercise-induced ([[Signs and symptoms#Dynamic and static|dynamic]]) symptoms, such as premature [[muscle fatigue]], rather than fixed [[Muscle weakness|weakness]] ([[Signs and symptoms#Dynamic and static|static]]) symptoms.<ref name=":12">{{Cite journal |last1=Darras |first1=B. T. |last2=Friedman |first2=N. R. |date=February 2000 |title=Metabolic myopathies: a clinical approach; part I |url=https://pubmed.ncbi.nlm.nih.gov/10738913/ |journal=Pediatric Neurology |volume=22 |issue=2 |pages=87–97 |doi=10.1016/s0887-8994(99)00133-2 |issn=0887-8994 |pmid=10738913}}</ref> Differential diagnoses for glycogen storage diseases that involve fixed muscle weakness, particularly of the [[proximal]] muscles, would be an [[inflammatory myopathy]] or a [[Limb–girdle muscular dystrophy|limb-girdle muscular dystrophy]].<ref name=":12" />

For those with exercise intolerance and/or proximal muscle weakness, the [[endocrinopathies]] should be considered.<ref>{{Citation |last1=Bhavaraju-Sanka |first1=R. |title=Myopathy, Endocrine |date=2014-01-01 |url=https://www.sciencedirect.com/science/article/pii/B978012385157400628X |pages=259–264 |editor-last=Aminoff |editor-first=Michael J. |access-date=2023-05-24 |place=Oxford |publisher=Academic Press |language=en |isbn=978-0-12-385158-1 |last2=Jackson |first2=C. E. |editor2-last=Daroff |editor2-first=Robert B. |encyclopedia=Encyclopedia of the Neurological Sciences (Second Edition)}}</ref><ref name=":13">{{Cite journal |last1=Rodolico |first1=Carmelo |last2=Bonanno |first2=Carmen |last3=Pugliese |first3=Alessia |last4=Nicocia |first4=Giulia |last5=Benvenga |first5=Salvatore |last6=Toscano |first6=Antonio |date=2020-09-01 |title=Endocrine myopathies: clinical and histopathological features of the major forms |journal=Acta Myologica |volume=39 |issue=3 |pages=130–135 |doi=10.36185/2532-1900-017 |issn=1128-2460 |pmc=7711326 |pmid=33305169}}</ref><ref name=":14">{{Cite journal |last1=Sharma |first1=Vikas |last2=Borah |first2=Papori |last3=Basumatary |first3=Lakshya J. |last4=Das |first4=Marami |last5=Goswami |first5=Munindra |last6=Kayal |first6=Ashok K. |date=2014 |title=Myopathies of endocrine disorders: A prospective clinical and biochemical study |journal=Annals of Indian Academy of Neurology |volume=17 |issue=3 |pages=298–302 |doi=10.4103/0972-2327.138505 |issn=0972-2327 |pmc=4162016 |pmid=25221399 |doi-access=free}}</ref> The timing of the symptoms of exercise intolerance, such as muscle fatigue and cramping, is important in order to help distinguish it from other [[Metabolic myopathy|metabolic myopathies]] such as [[Fatty-acid metabolism disorder|fatty acid metabolism disorders]].<ref>{{Cite web |last=Bhai |first=Salman |date=September 2021 |title=Neuromuscular Notes: Diagnosing Metabolic Myopathies |url=https://practicalneurology.com/articles/2021-sept/neuromuscular-notes-diagnosing-metabolic-myopathies |access-date=May 24, 2023 |website=Practical Neurology |language=en}}</ref>

Problems originating within the circulatory system, rather than the muscle itself, can produce exercise-induced muscle fatigue, pain and cramping that alleviates with rest, resulting from inadequate blood flow ([[ischemia]]) to the muscles. Ischemia that often produces symptoms in the leg muscles includes [[intermittent claudication]], [[popliteal artery entrapment syndrome]], and [[chronic venous insufficiency]].

Diseases disrupting the neuromuscular junction can cause abnormal muscle fatigue, such as [[myasthenia gravis]], an autoimmune disease.<ref>{{Cite journal |last=Gilhus |first=Nils Erik |date=2021-03-01 |title=Physical training and exercise in myasthenia gravis |url=https://www.sciencedirect.com/science/article/pii/S0960896620306982 |journal=Neuromuscular Disorders |volume=31 |issue=3 |pages=169–173 |doi=10.1016/j.nmd.2020.12.004 |pmid=33461846 |s2cid=229372884 |issn=0960-8966|hdl=11250/2767222 |hdl-access=free }}</ref> Similar, are [[Lambert–Eaton myasthenic syndrome]] (autoimmune) and the [[congenital myasthenic syndrome]]s (genetic).

Diseases can disrupt glycogen metabolism [[Disease#Concepts|secondary]] to the primary disease. Abnormal thyroid function—hypo- and hyperthyroidism—can manifest as myopathy with symptoms of exercise-induced muscle fatigue, cramping, muscle pain and may include proximal weakness or muscle hypertrophy (particularly of the calves).<ref>{{Cite web |title=Myopathies associated with thyroid disease |url=https://www.medlink.com/articles/myopathies-associated-with-thyroid-disease |access-date=2023-05-24 |website=MedLink Neurology |language=en}}</ref><ref name=":13" />  [[Hypothyroidism]] up-regulates glycogen synthesis and down-regulates glycogenolysis and glycolysis; conversely, [[hyperthyroidism]] does the reverse, up-regulating glycogenolysis and glycolysis while down-regulating glycogen synthesis.<ref name=":15">{{Cite journal |last1=Dimitriadis |first1=G D |last2=Leighton |first2=B |last3=Parry-Billings |first3=M |last4=West |first4=D |last5=Newsholme |first5=E A |date=1989-01-15 |title=Effects of hypothyroidism on the sensitivity of glycolysis and glycogen synthesis to insulin in the soleus muscle of the rat. |journal=Biochemical Journal |volume=257 |issue=2 |pages=369–373 |doi=10.1042/bj2570369 |issn=0264-6021 |pmc=1135589 |pmid=2649073}}</ref><ref name=":16">{{Cite journal |last1=Celsing |first1=F. |last2=Blomstrand |first2=E. |last3=Melichna |first3=J. |last4=Terrados |first4=N. |last5=Clausen |first5=N. |last6=Lins |first6=P. E. |last7=Jansson |first7=E. |date=April 1986 |title=Effect of hyperthyroidism on fibre-type composition, fibre area, glycogen content and enzyme activity in human skeletal muscle |url=https://pubmed.ncbi.nlm.nih.gov/2937605/ |journal=Clinical Physiology |volume=6 |issue=2 |pages=171–181 |doi=10.1111/j.1475-097x.1986.tb00066.x |issn=0144-5979 |pmid=2937605}}</ref><ref>{{Cite journal |last=Brenta |first=Gabriela |date=2011-09-19 |title=Why Can Insulin Resistance Be a Natural Consequence of Thyroid Dysfunction? |journal=Journal of Thyroid Research |language=en |volume=2011 |pages=e152850 |doi=10.4061/2011/152850 |issn=2090-8067 |pmc=3175696 |pmid=21941681 |doi-access=free}}</ref><ref name=":13" /><ref name=":17">{{Citation |last1=Fariduddin |first1=Maria M. |title=Hypothyroid Myopathy |date=2023 |url=http://www.ncbi.nlm.nih.gov/books/NBK519513/ |work=StatPearls |access-date=2023-05-24 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=30137798 |last2=Bansal |first2=Nidhi}}</ref>

Prolonged hypo- and hyperthyroid myopathy leads to atrophy of type II (fast-twitch/glycolytic) [[Skeletal muscle#Fiber types|muscle fibres]], and a predominance of type I (slow-twitch/oxidative) muscle fibres.<ref name=":16" /><ref name=":13" /><ref name=":14" /> Muscle biopsy shows abnormal muscle glycogen: high accumulation in hypothyroidism and low accumulation in hyperthyroidism.<ref name=":17" /><ref name=":15" /><ref name=":16" /> Hypothyroid myopathy includes [[Kocher–Debre–Semelaigne syndrome|Kocher-Debre-Semelaigne syndrome]] (childhood-onset), [[Hoffmann syndrome|Hoffman syndrome]] (adult-onset), myasthenic syndrome, and atrophic form.<ref name=":17" />

In patients with increased growth hormone, muscle biopsy includes, among other features, excess glycogen deposition.<ref>{{Citation |last=Orrell |first=Richard W. |title=Myopathies |date=2007-01-01 |volume=86 |pages=343–355 |access-date=2023-05-24 |series=Handbook of Clinical Neurology |chapter=Endocrine myopathies |chapter-url=https://www.sciencedirect.com/science/article/pii/S0072975207860179 |publisher=Elsevier |language=en |doi=10.1016/S0072-9752(07)86017-9 |isbn=9780444518996 |pmid=18809009}}</ref>

EPG5-related [[Vici syndrome]] is a multisystem disorder, a congenital disorder of [[autophagy]], with muscle biopsy showing excess glycogen accumulation, among other myopathic features.<ref>{{Cite journal |last1=Byrne |first1=Susan |last2=Dionisi-Vici |first2=Carlo |last3=Smith |first3=Luke |last4=Gautel |first4=Mathias |last5=Jungbluth |first5=Heinz |date=2016-02-29 |title=Vici syndrome: a review |journal=Orphanet Journal of Rare Diseases |volume=11 |pages=21 |doi=10.1186/s13023-016-0399-x |doi-access=free |issn=1750-1172 |pmc=4772338 |pmid=26927810}}</ref>

It is interesting to note, in comparison to hypothyroid myopathy, that McArdle disease ([[Glycogen storage disease type V|GSD-V]]), which is by far the most commonly diagnosed of the muscle GSDs and therefore the most studied,<ref name=":19" /><ref name=":5" /><ref name=":6" /> has as its second highest [[comorbidity]] endocrine disease (chiefly hypothyroidism)<ref>{{Cite journal |last1=Scalco |first1=Renata S. |last2=Lucia |first2=Alejandro |last3=Santalla |first3=Alfredo |last4=Martinuzzi |first4=Andrea |last5=Vavla |first5=Marinela |last6=Reni |first6=Gianluigi |last7=Toscano |first7=Antonio |last8=Musumeci |first8=Olimpia |last9=Voermans |first9=Nicol C. |last10=Kouwenberg |first10=Carlyn V. |last11=Laforêt |first11=Pascal |last12=San-Millán |first12=Beatriz |last13=Vieitez |first13=Irene |last14=Siciliano |first14=Gabriele |last15=Kühnle |first15=Enrico |date=2020-11-24 |title=Data from the European registry for patients with McArdle disease and other muscle glycogenoses (EUROMAC) |journal=Orphanet Journal of Rare Diseases |volume=15 |issue=1 |pages=330 |doi=10.1186/s13023-020-01562-x |issn=1750-1172 |pmc=7687836 |pmid=33234167 |doi-access=free}}</ref><ref name=":5" /> and that some patients with McArdle disease also have hypertrophy of the calf muscles.<ref name=":11" /> Late-onset Pompe disease ([[Glycogen storage disease type II|GSD-II]]) also has calf hypertrophy and hypothyroidism as comorbidities.<ref name=":18" /><ref>{{Cite journal |last1=Schneider |first1=Joseph |last2=Burmeister |first2=Lynn A. |last3=Rudser |first3=Kyle |last4=Whitley |first4=Chester B. |last5=Jarnes Utz |first5=Jeanine |date=September 2016 |title=Hypothyroidism in late-onset Pompe disease |journal=Molecular Genetics and Metabolism Reports |volume=8 |pages=24–27 |doi=10.1016/j.ymgmr.2016.06.002 |issn=2214-4269 |pmc=4932620 |pmid=27408821}}</ref><ref>{{Cite journal |last1=Fatehi |first1=Farzad |last2=Ashrafi |first2=Mahmoud Reza |last3=Babaee |first3=Marzieh |last4=Ansari |first4=Behnaz |last5=Beiraghi Toosi |first5=Mehran |last6=Boostani |first6=Reza |last7=Eshraghi |first7=Peyman |last8=Fakharian |first8=Atefeh |last9=Hadipour |first9=Zahra |last10=Haghi Ashtiani |first10=Bahram |last11=Moravej |first11=Hossein |last12=Nilipour |first12=Yalda |last13=Sarraf |first13=Payam |last14=Sayadpour Zanjani |first14=Keyhan |last15=Nafissi |first15=Shahriar |date=2021 |title=Recommendations for Infantile-Onset and Late-Onset Pompe Disease: An Iranian Consensus |journal=Frontiers in Neurology |volume=12 |page=739931 |doi=10.3389/fneur.2021.739931 |issn=1664-2295 |pmc=8490649 |pmid=34621239 |doi-access=free}}</ref>

Poor diet and [[malabsorption]] diseases (such as celiac disease) may lead to malnutrition of essential vitamins necessary for glycogen metabolism within the muscle cells. Malnutrition typically presents with systemic symptoms, but in rare instances can be limited to myopathy.<ref>{{Cite journal |last1=Rasheed |first1=Khalid |last2=Sethi |first2=Pooja |last3=Bixby |first3=Eric |date=May 2013 |title=Severe vitamin d deficiency induced myopathy associated with rhabydomyolysis |journal=North American Journal of Medical Sciences |volume=5 |issue=5 |pages=334–336 |doi=10.4103/1947-2714.112491 |doi-broken-date=1 November 2024 |issn=2250-1541 |pmc=3690793 |pmid=23814767 |doi-access=free}}</ref> [[Vitamin D deficiency]] myopathy (also known as [[Osteomalacia|osteomalic]] myopathy due to the interplay between vitamin D and calcium) results in muscle weakness, predominantly of the proximal muscles; with muscle biopsy showing abnormal glycogen accumulation, atrophy of type II (fast-twitch/glycolytic) muscle fibres, and diminished calcium uptake by the sarcoplasmic reticulum (needed for muscle contraction).<ref name=":20">{{Cite journal |last1=Polly |first1=Patsie |last2=Tan |first2=Timothy C. |date=2014 |title=The role of vitamin D in skeletal and cardiac muscle function |journal=Frontiers in Physiology |volume=5 |pages=145 |doi=10.3389/fphys.2014.00145 |issn=1664-042X |pmc=3995052 |pmid=24782788 |doi-access=free}}</ref><ref>{{Cite journal |last1=Yoshikawa |first1=S. |last2=Nakamura |first2=T. |last3=Tanabe |first3=H. |last4=Imamura |first4=T. |date=June 1979 |title=Osteomalacic myopathy |journal=Endocrinologia Japonica |volume=26 |issue=Suppl |pages=65–72 |doi=10.1507/endocrj1954.26.supplement_65 |issn=0013-7219 |pmid=467350 |doi-access=free}}</ref><ref>{{Cite journal |last1=Das |first1=Anamica |last2=Gopinath |first2=Suchitra D. |last3=Arimbasseri |first3=Gopalakrishnan Aneeshkumar |date=February 2022 |title=Systemic ablation of vitamin D receptor leads to skeletal muscle glycogen storage disorder in mice |journal=Journal of Cachexia, Sarcopenia and Muscle |volume=13 |issue=1 |pages=467–480 |doi=10.1002/jcsm.12841 |issn=2190-6009 |pmc=8818613 |pmid=34877816}}</ref> Although Vitamin D deficiency myopathy typically includes muscle atrophy,<ref name=":20" /> rarely calf muscle hypertrophy has been reported.<ref>{{Cite journal |last1=Hassan |first1=Ijas |last2=Bhanudeep |first2=Singanamalla |last3=Madaan |first3=Priyanka |last4=Chhajed |first4=Monika |last5=Saini |first5=Lokesh |date=2021 |title=Bilateral Calf Hypertrophy and Isolated Motor Delay: Think Beyond Muscular Dystrophy |journal=Journal of Pediatric Neurosciences |volume=16 |issue=2 |pages=173–174 |doi=10.4103/jpn.JPN_171_20 |issn=1817-1745 |pmc=8706592 |pmid=35018192 |doi-access=free}}</ref><ref>{{Cite journal |last1=Reimers |first1=C. D. |last2=Schlotter |first2=B. |last3=Eicke |first3=B. M. |last4=Witt |first4=T. N. |date=November 1996 |title=Calf enlargement in neuromuscular diseases: a quantitative ultrasound study in 350 patients and review of the literature |url=https://pubmed.ncbi.nlm.nih.gov/8981297/ |journal=Journal of the Neurological Sciences |volume=143 |issue=1–2 |pages=46–56 |doi=10.1016/s0022-510x(96)00037-8 |issn=0022-510X |pmid=8981297 |s2cid=25971689}}</ref>

Exercise-induced, electrically silent, muscle cramping and stiffness (transient muscle contractures or "pseudomyotonia") are seen not only in GSD types V, VII, IXd, X, XI, XII, and XIII, but also in [[Brody myopathy|Brody disease]], [[Rippling muscle disease]] types 1 and 2, and [[Caveolin 3|CAV3]]-related hyperCKemia (Elevated serum creatine phosphokinase).<ref name=":21">{{Cite web |title=Exercise-induced muscle cramps (Concept Id: C1855578) - MedGen - NCBI |url=https://www.ncbi.nlm.nih.gov/medgen/383715#:~:text=Disease%20or%20Syndrome-,Myopathy%20with%20myalgia,%20increased%20serum%20creatine%20kinase,%20and%20with%20or,adult)%20onset%20has%20also%20been |access-date=2023-12-28 |website=www.ncbi.nlm.nih.gov |language=en}}</ref> Unlike the other myopathies, in Brody disease the muscle cramping is painless.<ref name=":22">{{Cite web |title=BRODY DISEASE; BROD |url=https://www.omim.org/entry/601003 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref><ref>{{Cite journal |last1=Molenaar |first1=Joery P. |last2=Verhoeven |first2=Jamie I. |last3=Rodenburg |first3=Richard J. |last4=Kamsteeg |first4=Erik J. |last5=Erasmus |first5=Corrie E. |last6=Vicart |first6=Savine |last7=Behin |first7=Anthony |last8=Bassez |first8=Guillaume |last9=Magot |first9=Armelle |last10=Péréon |first10=Yann |last11=Brandom |first11=Barbara W. |last12=Guglielmi |first12=Valeria |last13=Vattemi |first13=Gaetano |last14=Chevessier |first14=Frédéric |last15=Mathieu |first15=Jean |date=2020-02-01 |title=Clinical, morphological and genetic characterization of Brody disease: an international study of 40 patients |journal=Brain: A Journal of Neurology |volume=143 |issue=2 |pages=452–466 |doi=10.1093/brain/awz410 |issn=1460-2156 |pmc=7009512 |pmid=32040565}}</ref> Like GSD types II, III, and V, a pseudoathletic appearance of muscle hypertrophy is also seen in some with Brody disease and Rippling muscle disease.<ref name=":22" /><ref>{{Cite web |title=RIPPLING MUSCLE DISEASE 1; RMD1 |url=https://www.omim.org/entry/600332 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref><ref>{{Cite web |title=RIPPLING MUSCLE DISEASE 2; RMD2 |url=https://www.omim.org/entry/606072 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref>

Erythrocyte lactate transporter defect (formerly ''Lactate transporter defect, myopathy due to'') also includes exercise-induced, electrically silent, painful muscle cramping and transient contractures; as well as exercise-induced muscle fatigue.<ref name=":21" /><ref name=":23">{{Cite web |title=ERYTHROCYTE LACTATE TRANSPORTER DEFECT |url=https://www.omim.org/entry/245340 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref> EMG and muscle biopsy is normal however, as the defect is not in the muscle but in the red blood cells that should clear lactate buildup from exercising muscles.<ref name=":23" />

Although most muscular dystrophies have fixed muscle weakness rather than exercise-induced muscle fatigue and/or cramping, there are a few exceptions. Limb–girdle muscular dystrophy autosomal recessive 23 (LGMD R23) has calf hypertrophy and exercise-induced cramping.<ref>{{Cite web |title=MUSCULAR DYSTROPHY, LIMB-GIRDLE, AUTOSOMAL RECESSIVE 23; LGMDR23 |url=https://www.omim.org/entry/618138 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref> Myofibrillar myopathy 10 (MFM10) has exercise-induced muscle fatigue, cramping and stiffness, with hypertrophic neck and shoulder girdle muscles.<ref>{{Cite web |title=MYOFIBRILLAR MYOPATHY 10; MFM10 |url=https://www.omim.org/entry/619040 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref> LGMD R28 has calf hypertrophy and exercise-induced muscle fatigue and pain.<ref>{{Cite web |title=MUSCULAR DYSTROPHY, LIMB-GIRDLE, AUTOSOMAL RECESSIVE 28; LGMDR28 |url=https://www.omim.org/entry/620375 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref> LGMD R8 has calf pseudohypertrophy and exercise-induced weakness (fatigue) and pain.<ref>{{Cite web |title=MUSCULAR DYSTROPHY, LIMB-GIRDLE, AUTOSOMAL RECESSIVE 8; LGMDR8 |url=https://www.omim.org/entry/254110 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref> LGMD R15 (a.k.a MDDGC3) has muscle hypertrophy, proximal muscle weakness, and muscle fatigue.<ref>{{Cite web |title=MUSCULAR DYSTROPHY-DYSTROGLYCANOPATHY (LIMB-GIRDLE), TYPE C, 3; MDDGC3 |url=https://www.omim.org/entry/613157 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref>

DMD-related myopathies of [[Duchenne muscular dystrophy|Duchenne]] and [[Becker muscular dystrophy]] are known for fixed muscle weakness and pseudohypertrophic calf muscles, but they also have secondary [[Mitochondrial myopathy|muscular mitochondrial impairment]] causing low ATP production; as well as decreasing type II (fast-twitch/glycolytic) muscle fibres, producing a predominance of type I (slow-twitch/oxidative) muscle fibres.<ref>{{Cite journal |last=Heydemann |first=Ahlke |date=2018-06-20 |title=Skeletal Muscle Metabolism in Duchenne and Becker Muscular Dystrophy-Implications for Therapies |journal=Nutrients |volume=10 |issue=6 |pages=796 |doi=10.3390/nu10060796 |doi-access=free |issn=2072-6643 |pmc=6024668 |pmid=29925809}}</ref> DMD-related childhood-onset milder phenotypes present with exercise-induced muscle cramping, stiffness, pain, fatigue, and elevated CK.<ref>{{Cite journal |last1=Veerapandiyan |first1=Aravindhan |last2=Shashi |first2=Vandana |last3=Jiang |first3=Yong-Hui |last4=Gallentine |first4=William Brian |last5=Schoch |first5=Kelly |last6=Smith |first6=Edward Clinton |date=December 2010 |title=Pseudometabolic presentation of dystrophinopathy due to a missense mutation |journal=Muscle & Nerve |volume=42 |issue=6 |pages=975–979 |doi=10.1002/mus.21823 |issn=1097-4598 |pmc=5506871 |pmid=21104870}}</ref> Becker muscular dystrophy has adult-onset exercise-induced muscle cramping, pain, and elevated CK.<ref>{{Cite web |title=MUSCULAR DYSTROPHY, BECKER TYPE; BMD |url=https://www.omim.org/entry/300376 |access-date=2023-12-29 |website=www.omim.org |language=en-us}}</ref>

[[Tubular aggregate myopathy]] (TAM) types 1 and 2 has exercise-induced muscle pain, fatigue, stiffness, with proximal muscle weakness and calf muscle pseudohypertrophy. TAM1 has cramping at rest, while TAM2 has cramping during exercise.<ref>{{Cite web |title=Tubular aggregate myopathy - About the Disease - Genetic and Rare Diseases Information Center |url=https://rarediseases.info.nih.gov/diseases/3884/tubular-aggregate-myopathy |access-date=2023-11-11 |website=rarediseases.info.nih.gov |language=en}}</ref><ref name=":24">{{Cite journal |last1=Morin |first1=Gilles |last2=Biancalana |first2=Valérie |last3=Echaniz-Laguna |first3=Andoni |last4=Noury |first4=Jean-Baptiste |last5=Lornage |first5=Xavière |last6=Moggio |first6=Maurizio |last7=Ripolone |first7=Michela |last8=Violano |first8=Raffaella |last9=Marcorelles |first9=Pascale |last10=Maréchal |first10=Denis |last11=Renaud |first11=Florence |last12=Maurage |first12=Claude-Alain |last13=Tard |first13=Céline |last14=Cuisset |first14=Jean-Marie |last15=Laporte |first15=Jocelyn |date=January 2020 |title=Tubular aggregate myopathy and Stormorken syndrome: Mutation spectrum and genotype/phenotype correlation |journal=Human Mutation |volume=41 |issue=1 |pages=17–37 |doi=10.1002/humu.23899 |issn=1098-1004 |pmid=31448844|doi-access=free }}</ref><ref>{{Cite web |title=MYOPATHY, TUBULAR AGGREGATE, 1; TAM1 |url=https://www.omim.org/entry/160565 |access-date=2023-11-11 |website=www.omim.org |language=en-us}}</ref><ref>{{Cite web |title=MYOPATHY, TUBULAR AGGREGATE, 2; TAM2 |url=https://www.omim.org/entry/615883 |access-date=2023-11-11 |website=www.omim.org |language=en-us}}</ref> Stormorken syndrome includes the symptoms of TAM, but is a more severe presentation including short stature and other abnormalities.<ref name=":24" /> [[Satoyoshi syndrome]] has exercise-induced painful muscle cramps, muscle hypertrophy, and short stature.<ref>{{Cite web |title=SATOYOSHI SYNDROME |url=https://www.omim.org/entry/600705 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref> Dimethylglycine dehydrogenase deficiency has muscle fatigue, elevated CK, and fishy body odour.<ref>{{Cite web |title=DIMETHYLGLYCINE DEHYDROGENASE DEFICIENCY; DMGDHD |url=https://www.omim.org/entry/605850 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref> Myopathy with myalgia, increased serum creatine kinase, with or without episodic rhabdomyolysis (MMCKR) has exercise-induced muscle cramps, pain, and fatigue; with some exhibiting proximal muscle weakness.<ref>{{Cite web |title=MYOPATHY WITH MYALGIA, INCREASED SERUM CREATINE KINASE, AND WITH OR WITHOUT EPISODIC RHABDOMYOLYSIS; MMCKR |url=https://www.omim.org/entry/620138 |access-date=2023-12-28 |website=www.omim.org |language=en-us}}</ref>

==== Liver ====
''(help wikipedia by contributing to this subsection)''

Glycogenosis-like phenotype of [[congenital hyperinsulinism]] due to [[Hepatocyte nuclear factor 4 alpha|HNF4A]] mutation or [[MODY 1|MODY1]] (maturity-onset diabetes of the young, type 1). This phenotype of MODY1 has [[Large for gestational age|macrosomia]] and infantile-onset hyperinsulinemic hypoglycemia, physiological 3-OH butyrate, increased triglyceride serum levels, increased level of glycogen in liver and erythrocytes, increased liver transaminases, transient [[hepatomegaly]], renal [[Fanconi syndrome]], and later develop liver cirrhosis, decreased succinate-dependent respiration (mitochondrial dysfunction), rickets, [[nephrocalcinosis]], chronic kidney disease, and diabetes.<ref>{{Cite journal |last1=Grassi |first1=Mara |last2=Laubscher |first2=Bernard |last3=Pandey |first3=Amit V. |last4=Tschumi |first4=Sibylle |last5=Graber |first5=Franziska |last6=Schaller |first6=André |last7=Janner |first7=Marco |last8=Aeberli |first8=Daniel |last9=Hewer |first9=Ekkehard |last10=Nuoffer |first10=Jean-Marc |last11=Gautschi |first11=Matthias |date=August 2023 |title=Expanding the p.(Arg85Trp) Variant-Specific Phenotype of HNF4A: Features of Glycogen Storage Disease, Liver Cirrhosis, Impaired Mitochondrial Function, and Glomerular Changes |journal=Molecular Syndromology |volume=14 |issue=4 |pages=347–361 |doi=10.1159/000529306 |issn=1661-8769 |pmid=37766831|pmc=10521240 }}</ref><ref>{{Cite journal |last1=Stanik |first1=Juraj |last2=Skopkova |first2=Martina |last3=Brennerova |first3=Katarina |last4=Danis |first4=Daniel |last5=Rosolankova |first5=Monika |last6=Salingova |first6=Anna |last7=Bzduch |first7=Vladimir |last8=Klimes |first8=Iwar |last9=Gasperikova |first9=Daniela |date=April 2017 |title=Congenital hyperinsulinism and glycogenosis-like phenotype due to a novel HNF4A mutation |url=https://pubmed.ncbi.nlm.nih.gov/28242437/ |journal=Diabetes Research and Clinical Practice |volume=126 |pages=144–150 |doi=10.1016/j.diabres.2017.02.014 |issn=1872-8227 |pmid=28242437}}</ref><ref>{{Cite web |title=Entry - #125850 - MATURITY-ONSET DIABETES OF THE YOUNG, TYPE 1; MODY1 - OMIM |url=https://www.omim.org/entry/125850 |access-date=2024-05-23 |website=www.omim.org}}</ref>

== Treatment ==
Treatment is dependent on the type of glycogen storage disease. Von Gierke disease ([[Glycogen storage disease type I|GSD-I]]) is typically treated with frequent small meals of [[carbohydrates]] and [[cornstarch]], called [[modified cornstarch therapy]], to prevent low blood sugar, while other treatments may include [[allopurinol]] and [[human granulocyte colony stimulating factor]].<ref name="Rare2017">{{cite web|title=Glycogen Storage Disease Type I - NORD (National Organization for Rare Disorders)|url=https://rarediseases.org/rare-diseases/glycogen-storage-disease-type-i/|website=NORD (National Organization for Rare Disorders)|access-date=23 March 2017}}</ref>

Cori/Forbes disease ([[Glycogen storage disease type III|GSD-III]]) treatment may use modified cornstarch therapy, a high protein diet with a preference to complex carbohydrates. However, unlike GSD-I, [[gluconeogenesis]] is functional, so simple sugars (sucrose, fructose, and lactose) are not prohibited.<ref name=":8" />

A ketogenic diet has demonstrated beneficial for McArdle disease ([[Glycogen storage disease type V|GSD-V]]) as ketones readily convert to acetyl CoA for oxidative phosphorylation, whereas free fatty acids take a few minutes to convert into acetyl CoA.<ref>{{Cite journal |last1=Løkken |first1=Nicoline |last2=Hansen |first2=Kit K. |last3=Storgaard |first3=Jesper H. |last4=Ørngreen |first4=Mette C. |last5=Quinlivan |first5=Ros |last6=Vissing |first6=John |date=July 2020 |title=Titrating a modified ketogenic diet for patients with McArdle disease: A pilot study |url=https://onlinelibrary.wiley.com/doi/10.1002/jimd.12223 |journal=Journal of Inherited Metabolic Disease |language=en |volume=43 |issue=4 |pages=778–786 |doi=10.1002/jimd.12223 |pmid=32060930 |s2cid=211121921 |issn=0141-8955}}</ref><ref>{{Cite journal |last1=Løkken |first1=Nicoline |last2=Voermans |first2=Nicol C. |last3=Andersen |first3=Linda K. |last4=Karazi |first4=Walaa |last5=Reason |first5=Stacey L. |last6=Zweers |first6=Heidi |last7=Wilms |first7=Gustav |last8=Santalla |first8=Alfredo |last9=Susanibar |first9=Edward |last10=Lucia |first10=Alejandro |last11=Vissing |first11=John |date=2023-02-07 |title=Patient-Reported Experiences with a Low-Carbohydrate Ketogenic Diet: An International Survey in Patients with McArdle Disease |journal=Nutrients |volume=15 |issue=4 |pages=843 |doi=10.3390/nu15040843 |issn=2072-6643 |pmc=9964801 |pmid=36839201 |doi-access=free }}</ref>

For [[Phosphoglucomutase#Disease relevance|phosphoglucomutase deficiency]] (formerly GSD-XIV), D-galactose supplements and exercise training has shown favourable improvement of signs and symptoms.<ref name=":9" /> In terms of exercise training, some patients with phosphoglucomutase deficiency also experience "second wind."<ref name=":9" /><ref name=":10" />

For McArdle disease (GSD-V), regular aerobic exercise utilizing "[[second wind]]" to enable the muscles to become aerobically conditioned, as well as anaerobic exercise (strength training) that follows the activity adaptations so as not to cause muscle injury, helps to improve exercise intolerance symptoms and maintain overall health.<ref name=":5" /><ref name=":6">{{Cite book |last=Wakelin |first=Andrew |url=https://www.iamgsd.org/_files/ugd/c951b2_91a5802caa2144d5aedbb0489c1cf543.pdf |title=Living With McArdle Disease |publisher=IamGSD (International Association for Muscle Glycogen Storage Disease) |year=2017}}</ref><ref name=":3">{{Cite journal |last=Kitaoka |first=Yu |date=February 25, 2014 |title=McArdle Disease and Exercise Physiology |journal=Biology |language=en |volume=3 |issue=1 |pages=157–166 |doi=10.3390/biology3010157 |pmid=24833339 |pmc=4009758 |issn=2079-7737 |doi-access=free }}</ref><ref name=":4">{{Cite journal |last1=Salazar-Martínez |first1=Eduardo |last2=Santalla |first2=Alfredo |last3=Valenzuela |first3=Pedro L. |last4=Nogales-Gadea |first4=Gisela |last5=Pinós |first5=Tomàs |last6=Morán |first6=María |last7=Santos-Lozano |first7=Alejandro |last8=Fiuza-Luces |first8=Carmen |last9=Lucia |first9=Alejandro |date=2021 |title=The Second Wind in McArdle Patients: Fitness Matters |journal=Frontiers in Physiology |volume=12 |pages=744632 |doi=10.3389/fphys.2021.744632 |issn=1664-042X |pmc=8555491 |pmid=34721068 |doi-access=free }}</ref> Studies have shown that regular low-moderate aerobic exercise increases peak power output, increases peak oxygen uptake ([[VO2 max|V̇O<sub>2</sub>]]<sub>peak</sub>), lowers heart rate, and lowers serum CK in individuals with McArdle disease.<ref name=":3" /><ref name=":4" />

Regardless of whether the patient experiences [[Signs and symptoms|symptoms]] of muscle pain, muscle fatigue, or cramping, the phenomenon of second wind having been achieved is demonstrable by the [[Signs and symptoms|sign]] of an increased heart rate dropping while maintaining the same speed on the treadmill.<ref name=":4" /> Inactive patients experienced second wind, demonstrated through relief of typical symptoms and the sign of an increased heart rate dropping, while performing low-moderate aerobic exercise (walking or brisk walking).<ref name=":4" />

Conversely, patients that were regularly active did not experience the typical symptoms during low-moderate aerobic exercise (walking or brisk walking), but still demonstrated second wind by the sign of an increased heart rate dropping.<ref name=":4" /><ref name=":7">{{Cite journal |last1=Perez |first1=M |last2=Martin |first2=M A |last3=Rubio |first3=J C |last4=Maté-Muñoz |first4=J L |last5=Gómez-Gallego |first5=F |last6=Foster |first6=C |last7=Andreu |first7=A L |last8=Arenas |first8=J |last9=Lucia |first9=A |date=August 2006 |title=Exercise capacity in a 78 year old patient with McArdle's disease: it is never too late to start exercising |journal=British Journal of Sports Medicine |volume=40 |issue=8 |pages=725–726 |doi=10.1136/bjsm.2006.026666 |issn=0306-3674 |pmc=2579473 |pmid=16864568}}</ref> For the regularly active patients, it took more strenuous exercise (very brisk walking/jogging or bicycling) for them to experience both the typical symptoms and relief thereof, along with the sign of an increased heart rate dropping, demonstrating second wind.<ref name=":4" /><ref name=":7" /><ref>{{Cite book |last=Wakelin |first=Andrew |url=https://www.iamgsd.org/_files/ugd/c951b2_452b11293216448caedd2909082fd924.pdf |title=101Tips for a good life with McArdle Disease |publisher=AGSD-UK |year=2013 |pages=52}}</ref>

In young children (<10 years old) with McArdle disease (GSD-V), it may be more difficult to detect the second wind phenomenon. They may show a normal heart rate, with normal or above normal peak cardio-respiratory capacity ([[VO2 max|V̇O<sub>2max</sub>]]).<ref name=":5" /><ref>{{Cite journal |last1=Pérez |first1=Margarita |last2=Ruiz |first2=Jonatan R. |last3=Fernández del Valle |first3=María |last4=Nogales-Gadea |first4=Gisela |last5=Andreu |first5=Antoni L. |last6=Arenas |first6=Joaquín |last7=Lucía |first7=Alejandro |date=2009-06-01 |title=The second wind phenomenon in very young McArdle's patients |url=https://www.sciencedirect.com/science/article/pii/S0960896609001151 |journal=Neuromuscular Disorders |language=en |volume=19 |issue=6 |pages=403–405 |doi=10.1016/j.nmd.2009.04.010 |pmid=19477644 |s2cid=31541581 |issn=0960-8966}}</ref> That said, patients with McArdle disease typically experience symptoms of exercise intolerance before the age of 10 years,<ref name=":5" /> with the median symptomatic age of 3 years.<ref name=":19">{{Cite journal |last1=Reason |first1=S. L. |last2=Voermans |first2=N. |last3=Lucia |first3=A. |last4=Vissing |first4=J. |last5=Quinlivan |first5=R. |last6=Bhai |first6=S. |last7=Wakelin |first7=A. |date=2023-06-12 |title=Development of Continuum of Care for McArdle disease: A practical tool for clinicians and patients |journal=Neuromuscular Disorders |volume=33 |issue=7 |pages=575–579 |doi=10.1016/j.nmd.2023.05.006 |issn=1873-2364 |pmid=37354872|s2cid=259141690 |doi-access=free }}</ref><ref>{{Cite journal |last1=Scalco |first1=Renata Siciliani |last2=Morrow |first2=Jasper M. |last3=Booth |first3=Suzanne |last4=Chatfield |first4=Sherryl |last5=Godfrey |first5=Richard |last6=Quinlivan |first6=Ros |date=September 2017 |title=Misdiagnosis is an important factor for diagnostic delay in McArdle disease |journal=Neuromuscular Disorders |volume=27 |issue=9 |pages=852–855 |doi=10.1016/j.nmd.2017.04.013 |issn=1873-2364 |pmid=28629675|s2cid=11797963 |doi-access=free }}</ref>

Tarui disease ([[Phosphofructokinase deficiency|GSD-VII]]) patients do not experience the "second wind" phenomenon; instead are said to be "out-of-wind."<ref name=":5" /><ref name=":6" /><ref>{{Citation |last1=Stojan |first1=George |title=151 - Metabolic, drug-induced, and other noninflammatory myopathies |date=2015-01-01 |url=https://www.sciencedirect.com/science/article/pii/B9780323091381001510 |work=Rheumatology (Sixth Edition) |pages=1255–1263 |editor-last=Hochberg |editor-first=Marc C. |access-date=2023-05-15 |place=Philadelphia |publisher=Mosby |language=en |isbn=978-0-323-09138-1 |last2=Christopher-Stine |first2=Lisa |editor2-last=Silman |editor2-first=Alan J. |editor3-last=Smolen |editor3-first=Josef S. |editor4-last=Weinblatt |editor4-first=Michael E.}}</ref> However, they can achieve sub-maximal benefit from lipid metabolism of free fatty acids during aerobic activity following a warm-up.<ref name=":5" />

== Epidemiology ==
[[File:Relative incidences of glycogen storage diseases.png|thumb|250px|Relative incidences of the main types of glycogen storage disease]]
Overall, according to a study in [[British Columbia]], approximately 2.3 children per 100,000 births (1 in 43,000) have some form of glycogen storage disease.<ref name="BC">{{cite journal |vauthors=Applegarth DA, Toone JR, Lowry RB |title=Incidence of inborn errors of metabolism in British Columbia, 1969–1996 |journal=Pediatrics |volume=105 |issue=1 |pages=e10 |date=January 2000 |pmid=10617747 |doi= 10.1542/peds.105.1.e10|s2cid=30266513 |doi-access= }}</ref> In the United States, they are estimated to occur in 1 per 20,000–25,000 births.<ref name="Roth">[http://emedicine.medscape.com/article/949937-overview eMedicine Specialties > Glycogen-Storage Disease Type I] Author: Karl S Roth. Updated: Aug 31, 2009</ref> Dutch incidence rate is estimated to be 1 per 40,000 births.
While a Mexican incidence showed 6.78:1000 male newborns.<ref name="Glucose-6-Phosphate dehydrogenase d" /><ref>{{cite journal |last1=Cantú-Reyna |first1=Consuelo |last2=Zepeda |first2=Luis Manuel |last3=Montemayor |first3=René |last4=Benavides |first4=Santiago |last5=González |first5=Héctor Javier |last6=Vázquez-Cantú |first6=Mercedes |last7=Cruz-Camino |first7=Héctor |title=Incidence of Inborn Errors of Metabolism by Expanded Newborn Screening in a Mexican Hospital |journal=Journal of Inborn Errors of Metabolism and Screening |date=27 September 2016 |volume=4 |pages=232640981666902 |doi=10.1177/2326409816669027|url=http://www.scielo.br/pdf/jiems/v4/2326-4594-jiems-4-e150013.pdf |doi-access=free }}</ref>

Within the category of muscle glycogenoses (muscle GSDs), McArdle disease (GSD-V) is by far the most commonly diagnosed.<ref name=":19" />

== See also ==
* [[Metabolic myopathy|Metabolic myopathies]]
* [[Inborn errors of carbohydrate metabolism]]

==References==
{{reflist|2}}

== External links ==
* [https://agsdus.org AGSD]. - Association for Glycogen Storage Disease. A US-based non-profit, parent and patient oriented support group dedicated to promoting the best interest of all the different types of glycogen storage disease.
* [https://agsd.org.uk/ AGSD-UK] - Association for Glycogen Storage Disease (UK). A UK-based charity which helps individuals and families affected by Glycogen Storage Disease by putting people in contact, providing information and support, publishing a magazine and holding conferences, workshops, courses and family events.
* [https://www.iamgsd.org IamGSD] - International Association for Muscle Glycogen Storage Disease. A non-profit, patient-led international group encouraging efforts by research and medical professionals, national support groups and individual patients worldwide.
* [https://worldpompe.org IPA] - International Pompe Association. (Pompe Disease is also known as GSD-II). A non-profit, federation of Pompe disease patient's groups world-wide. It seeks to coordinate activities and share experience and knowledge between different groups.
* [https://www.euromacregistry.eu/ EUROMAC] - EUROMAC is a European registry of patients affected by McArdle Disease and other rare neuromuscular glycogenoses.
* [https://research.sanfordhealth.org/rare-disease-registry CoRDS] - Coordination of Rare Diseases at Sanford (CoRDS) is a centralized international patient registry for all rare diseases. They work with patient advocacy groups, including IamGSD, individuals and researchers.
* [http://www.raredisorders.ca/ CORD] - Canadian Organization for Rare Disorders (CORD) is a Canadian national network for organizations representing all those with rare disorders. CORD provides a strong common voice to advocate for health policy and a healthcare system that works for those with rare disorders.
* [https://rarediseases.org NORD] - National Organization for Rare Disorders (NORD) is an American national non-profit patient advocacy organization that is dedicated to individuals with rare diseases and the organizations that serve them.
* [https://www.eurordis.org EURODIS] - Rare Diseases Europe (EURODIS) is a unique, non-profit alliance of over 700 rare disease patient organizations across Europe that work together to improve the lives of the 30 million people living with a rare disease in Europe.
{{Medical resources
|   DiseasesDB     =
|   ICD10          = {{ICD10|E|74|0|e|70}}
|   ICD9           = {{ICD9|271.0}}
|   ICDO           =
|   OMIM           =
|   MedlinePlus    =
|   eMedicineSubj  =
|   eMedicineTopic =
|   MeshID         = D006008
}}

{{Carbohydrate metabolic pathology}}
{{Authority control}}{{Diseases of myoneural junction and muscle}}{{Myopathy}}

[[Category:Inborn errors of carbohydrate metabolism]]
[[Category:Hepatology]]
[[Category:Rare diseases]]
[[Category:Diseases of liver]]
[[Category:Muscular disorders]]
[[Category:Metabolic disorders]]