Editing Congenital iodine deficiency syndrome

{{Short description|Impaired physical and mental development due to insufficient iodine intake}}
{{redirect|Cretin (medicine)||Cretin (disambiguation){{!}}Cretin}}
{{Infobox medical condition
| name            = Congenital iodine deficiency syndrome
| synonyms        = Endemic Cretinism<ref name="icd.who.int"/>
| image           = Joseph le crétin - Fonds Trutat - MHNT.PHa.912.PR34 cropped.jpg
| caption         = A man with congenital iodine deficiency syndrome
| pronounce       =
| field           = [[Endocrinology]]
| symptoms        = [[Goiter]], [[mental impairment]], [[failure to thrive|poor growth]], [[infertility]], [[hair loss]]
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| causes          =
| risks           =
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'''Congenital iodine deficiency syndrome''' ('''CIDS'''), also called '''cretinism''',<ref name=mw>{{cite web |url=https://www.merriam-webster.com/dictionary/cretinism |title=Cretinism |author=<!--Not stated--> |website=merriam-webster.com |publisher=Merriam-Webster |access-date=5 October 2019 |quote=a usually congenital condition marked by physical stunting and intellectual disability and caused by severe hypothyroidism}}</ref> is a medical condition present at birth marked by impaired physical and mental development, due to insufficient [[thyroid hormone|thyroid hormone production]] ([[hypothyroidism]]) often caused by insufficient dietary [[iodine]] during pregnancy. It is one cause of underactive thyroid function at birth, called [[congenital hypothyroidism]].<ref name=medterms>{{cite web |url=https://www.medicinenet.com/script/main/art.asp?articlekey=6551 |title=Medical Definition of Cretinism |author=William C. Shiel |website=medicinenet.com |publisher=MedicineNet |access-date=5 October 2019 |quote=Cretinism: Congenital hypothyroidism (underactivity of the thyroid gland at birth), which results in growth retardation, developmental delay, and other abnormal features. |archive-date=11 September 2017 |archive-url=https://web.archive.org/web/20170911105122/http://www.medicinenet.com/script/main/art.asp?articlekey=6551 |url-status=dead }}</ref> If untreated, it results in impairment of both physical and mental development. Symptoms may include: [[goiter]], poor length growth in infants, reduced adult stature, thickened skin, hair loss, enlarged tongue, a protruding abdomen, delayed [[bone maturation]] and [[puberty]] in children, [[dementia|mental deterioration]], [[Neurological disorder|neurological impairment]], impeded [[ovulation]], and [[infertility]] in adults.<ref>{{Cite web |title=Congenital hypothyroidism: MedlinePlus Genetics |url=https://medlineplus.gov/genetics/condition/congenital-hypothyroidism/ |access-date=2022-10-20 |website=medlineplus.gov |language=en}}</ref>

In developed countries, [[Newborn screening|thyroid function testing]] of newborns has assured that in those affected, treatment with the synthetic thyroid hormone [[thyroxine]] is begun promptly. This screening and treatment successfully [[cure|cures the disease]].<ref name=endocrinopathies/>

==Signs and symptoms==
[[File:Cretin group.jpg|thumb|Group of men and women of various ages with CIDS]]
Iodine deficiency causes gradual enlargement of the thyroid gland, referred to as a goiter. Poor length growth is apparent as early as the first year of life. Adult stature without treatment ranges from {{convert|100|to|160|cm|ftin|abbr=on}}, depending on severity, sex, and other genetic factors. Other signs include thickened skin, hair loss, enlarged tongue, and a protruding abdomen.<ref>{{cite book|title=Disease and Its Causes|year=1913|publisher=New York Henry Holt and Company London Williams and Norgate The University Press, Cambridge, USA|location=United States| chapter-url=http://s3.amazonaws.com/manybooks_pdf_new/councilmanw15281528315283-8?AWSAccessKeyId=AKIAITZP2AAM27ZGISNQ&Expires=1367017007&Signature=bLVYP0SQHeAi4HeGuy6qsaPNFmg%3D |first=W. .|last=Councilman|chapter=One}}</ref> In children, [[bone maturation]] and [[puberty]] are severely delayed. In adults, [[ovulation]] is impeded and [[infertility]] is common.<ref>{{cite web|title=Iodine deficiency may contribute to women's fertility problems|year=2018|publisher=Carolyn Crist, Reuters Health|url=https://www.reuters.com/article/us-health-iodine-fertility-women-idUSKBN1FE365|archive-url=https://web.archive.org/web/20210902152445/https://www.reuters.com/article/us-health-iodine-fertility-women-idUSKBN1FE365|url-status=dead|archive-date=September 2, 2021|access-date=}} March 2021</ref><ref>{{Cite journal|last1=Dunn|first1=John T.|last2=Delange|first2=Francois|date=2001-06-01|title=Damaged Reproduction: The Most Important Consequence of Iodine Deficiency|journal=The Journal of Clinical Endocrinology & Metabolism|volume=86|issue=6|pages=2360–2363|doi=10.1210/jcem.86.6.7611|pmid=11397823|issn=0021-972X|doi-access=free}}</ref>

Mental deterioration is common. Neurological impairment may be mild, with reduced [[muscle tone]] and [[motor coordination]], or so severe that the person cannot stand or walk. Cognitive impairment may also range from mild to so severe that the person is [[nonverbal]] and dependent on others for basic care. Thought and reflexes are slower.<ref>{{Cite journal|last=Kapil|first=Umesh|date=December 2007|title=Health Consequences of Iodine Deficiency|journal=Sultan Qaboos University Medical Journal|volume=7|issue=3|pages=267–272|issn=2075-051X|pmc=3074887|pmid=21748117}}</ref><ref>{{Cite journal|last1=HALPERN|first1=JEAN-PIERRE|last2=BOYAGES|first2=STEVEN C.|last3=MABERLY|first3=GLENDEN F.|last4=COLLINS|first4=JOHN K.|last5=EASTMAN|first5=CRESWELL J.|last6=MORRIS|first6=JOHN G.L.|title=The Neurology of Endemic Cretinism|date=1991-04-01|url=https://doi.org/10.1093/brain/114.2.825|journal=Brain|volume=114|issue=2|pages=825–841|doi=10.1093/brain/114.2.825|pmid=2043952|issn=0006-8950}}</ref>

==Cause==
[[File:Iodine_deficiency_world_map-DALYs_per_million_persons-WHO2012.svg|thumb|upright=1.2|[[:en:Disability-adjusted life year|Disability-adjusted life years]] (DALY) lost from iodine deficiency in 2012 in proportion to a million people
{{Div col|small=yes|colwidth=10em}}
{{legend|#ffff20|52–163}}
{{legend|#ffe820|181–217}}
{{legend|#ffd820|221–221}}
{{legend|#ffc020|222–310}}
{{legend|#ffa020|320–505}}
{{legend|#ff9a20|512–610}}
{{legend|#f08015|626–626}}
{{legend|#e06815|653–976}}
{{legend|#d85010|984–1,242}}
{{legend|#d02010|1,251–3,159}}
{{div col end}}]]
Around the world, the most common cause of congenital iodine deficiency syndrome (endemic cretinism)<ref name="icd.who.int">{{Cite web|url=https://icd.who.int/browse10/2019/en#/E00|title = ICD-10 Version:2019}}</ref> is dietary [[iodine deficiency]].

[[Iodine]] is an essential trace element, necessary for the synthesis of thyroid hormones. Iodine deficiency is the most common preventable cause of neonatal and childhood brain damage worldwide.<ref>{{cite journal |last1= Chen |first1= Zu-Pei |date= February 2010 |title= Cretinism Revisited |journal= Best Practice & Research Clinical Endocrinology & Metabolism  |volume= 24 |issue= 1|pages= 39–50|pmid= 20172469|doi= 10.1016/j.beem.2009.08.014|last2= Hetzel |first2= BS }}</ref> Although iodine is found in many foods, it is not universally present in all soils in adequate amounts. Most iodine, in iodide form, is in the oceans, where the iodide ions are reduced to elemental iodine, which then enters the atmosphere and falls to earth in rain, introducing iodine to soils. Soil deficient in iodine is most common inland, in mountainous areas, and in areas of frequent flooding. It can also occur in coastal regions, where iodine might have been removed from the soil by glaciation, as well as leaching by snow, water and heavy rainfall.<ref>[http://www.thyroidmanager.org/Chapter20/20-frame.htm Chapter 20. The Iodine Deficiency Disorders] {{webarchive|url=https://web.archive.org/web/20080313190009/http://www.thyroidmanager.org/Chapter20/20-frame.htm |date=2008-03-13 }} ''Thyroid Disease Manager''. Retrieved: 2011-06-26.</ref> Plants and animals grown in iodine-deficient soils are correspondingly deficient. Populations living in those areas without outside food sources are most at risk of iodine deficiency diseases.<ref>{{cite journal |vauthors=Gaitan E, Dunn JT |s2cid=43567038 |title=Epidemiology of iodine deficiency |journal=Trends Endocrinol. Metab. |volume=3 |issue=5 |pages=170–5 |year=1992 |pmid=18407097 |doi= 10.1016/1043-2760(92)90167-Y}}</ref>

==Diagnosis==
===Differential diagnosis===
Dwarfism may also be caused by malnutrition or other hormonal deficiencies, such as insufficient growth hormone secretion, [[hypopituitarism]], decreased secretion of [[growth hormone-releasing hormone]], deficient [[growth hormone receptor]] activity and downstream causes, such as [[insulin-like growth factor 1]] (IGF-1) deficiency.<ref>{{cite web |title=Medical information;types of dwarfism~r restricted growth |url=https://rgauk.org/medical-information |website=rgauk.org |publisher=rgauk |access-date=17 January 2020}}</ref>

==Prevention==
{{See also|Iodised salt}}
There are public health campaigns in many countries which involve iodine administration. As of December 2019, 122 countries have mandatory iodine food fortification programs.<ref name=Map>{{cite web|url=https://fortificationdata.org/map-number-of-nutrients/|title=Map: Count of Nutrients In Fortification Standards|website=Global Fortification Data Exchange|access-date=23 December 2019}}</ref>

==Treatment==
Congenital iodine deficiency has been almost eliminated in developed countries through iodine supplementation of food and by [[newborn screening]] using a blood test for thyroid function.<ref name=endocrinopathies>{{Cite journal | last1 = Pass | first1 = K. A. | last2 = Neto | first2 = E. C. | doi = 10.1016/j.ecl.2009.08.005 | title = Update: Newborn Screening for Endocrinopathies | journal = Endocrinology & Metabolism Clinics of North America | volume = 38 | issue = 4 | pages = 827–837 | year = 2009 | pmid = 19944295 }}</ref>

Treatment consists of lifelong administration of [[thyroxine]] (T4). Thyroxine must be dosed as tablets only, even to newborns, as the liquid oral suspensions and compounded forms cannot be depended on for reliable dosing. For infants, the T4 tablets are generally crushed and mixed with breast milk, formula milk or water.  If the medication is mixed with formulas containing iron or soya products, larger doses may be required, as these substances may alter the absorption of thyroid hormone from the gut.<ref name="pmid7596704">{{cite journal |vauthors=Chorazy PA, Himelhoch S, Hopwood NJ, Greger NG, Postellon DC | title = Persistent hypothyroidism in an infant receiving a soy formula: case report and review of the literature | journal = [[Pediatrics (journal)|Pediatrics]] | volume = 96 | issue = 1 Pt 1 | pages = 148–50 |date=July 1995 | pmid = 7596704 }}</ref>  Monitoring TSH blood levels every 2–3 weeks during the first months of life is recommended to ensure that affected infants are at the high end of normal range.<ref>{{Cite journal |last1=Kilberg |first1=Marissa J |last2=Rasooly |first2=Irit R |last3=LaFranchi |first3=Stephen H |last4=Bauer |first4=Andrew J |last5=Hawkes |first5=Colin P |date=2018 |title=Newborn Screening in the United States May Miss Mild Persistent Hypothyroidism |journal=The Journal of Pediatrics |volume=192 |pages=204–208 |doi=10.1016/j.jpeds.2017.09.003 |issn=0022-3476 |pmc=5823276 |pmid=29246344}}</ref>

==History==
[[File:Cretinnen aus Steiermark, 1819 gez. Loder, gest. Leopold Müller.jpg|thumb|upright=1.4|Cretinism ([[Styria]]), copper engraving, 1815]]

A [[Goitre|goiter]] is the most specific clinical marker of either the direct or indirect insufficient intake of iodine in the human body. There is evidence of goiter, and its medical treatment with iodine-rich algae and burnt sponges, in Chinese, Egyptian, and Roman ancient medical texts. In 1848, King [[Charles Albert of Sardinia|Carlo Alberto]] of [[Sardinia]] commissioned the first epidemiological study of congenital iodine deficiency syndrome, in northern [[Savoy]] where it was frequent. In past centuries, the well reported social diseases prevalent among the poorer social classes and farmers, caused by dietary and agricultural monocultures, were: [[pellagra]], [[rickets]], [[beriberi]], [[scurvy]] in long-term sailors, and the [[endemic goiter]] caused by iodine deficiency. However, this disease was less mentioned in medical books because it was erroneously considered to be an aesthetic rather than a clinical disorder.<ref>{{cite journal |author=Venturi, Sebastiano |title=Iodine Deficiency in the Population of Montefeltro, A Territory in Central Italy Inside the Regions of Emilia-Romagna, Tuscany and Marche |journal=International Journal of Anthropology |volume=29 |issue=1–2 |pages=1–12 |year=2014 |url=http://www.pontecorboli.com/digital1/inte-journal-of-anthropology-archive/ |access-date=2015-11-02 |archive-url=https://web.archive.org/web/20160304063248/http://www.pontecorboli.com/digital1/inte-journal-of-anthropology-archive/ |archive-date=2016-03-04 |url-status=dead }}</ref>

Congenital iodine-deficiency syndrome was especially common in areas of southern Europe around the Alps and was often described by ancient Roman writers and depicted by artists. The earliest Alpine mountain climbers sometimes came upon whole villages affected by it.<ref>Fergus Fleming, ''Killing Dragons: The Conquest of the Alps'', 2000, Grove Press, p. 179</ref> The prevalence of the condition was described from a medical perspective by several travellers and physicians in the late 18th and early 19th centuries.<ref>See, for example, [[William Coxe (historian)|William Coxe]], "Account of the [[Valais|Vallais]], and of the Goiters and Idiots of that Country," ''Universal Magazine of Knowledge & Pleasure'', vol. 67, Dec. 2, 1780.</ref>  At that time the cause was not known and it was often attributed to "stagnant air" in mountain valleys or "bad water". The proportion of people affected varied markedly throughout southern Europe and even within very small areas; it might be common in one valley and not another. The number of severely affected persons was always a minority, and most persons were only affected to the extent of having a goitre and some degree of reduced cognition and growth. The majority of such cases were still socially functional in their pastoral villages.<ref>{{Cite journal |last1=Weichenberger |first1=Christian X. |last2=Rivera |first2=Maria Teresa |last3=Vanderpas |first3=Jean |date=2020-10-02 |title=Familial Aggregation of Endemic Congenital Hypothyroidism Syndrome in Congo (DR): Historical Data |journal=Nutrients |volume=12 |issue=10 |pages=3021 |doi=10.3390/nu12103021 |issn=2072-6643 |pmc=7601371 |pmid=33023116|doi-access=free }}</ref>

More mildly affected areas of Europe and North America in the 19th century were referred to as "goitre belts". The degree of iodine deficiency was milder and manifested primarily as thyroid enlargement rather than severe mental and physical impairment. In Switzerland, for example, where soil does not contain a large amount of iodine, cases of congenital iodine deficiency syndrome were very abundant and even considered genetically caused. As the variety of food sources dramatically increased in Europe and North America and the populations became less completely dependent on locally grown food, the prevalence of endemic goitre diminished. This is supported by a 1979 WHO publication which concluded that "changes in the origin of food supplies may account for the otherwise unexplained disappearance of endemic goitre from a number of localities during the past 50 years".<ref>{{Cite book|last=De Maeyer, Lowenstein, Thilly|title=The Control of Endemic Goitre|publisher=WORLD HEALTH ORGANIZATION|year=1979|isbn=92-4-156060-6|location=Geneva, Switzerland|pages=9–10}}</ref>

The early 20th century saw the discovery of the relationships of neurological impairment with hypothyroidism due to iodine deficiency. Both have been largely eliminated in the developed world.<ref>{{cite web |url=https://www.lecturio.com/concepts/hypothyroidism/| title=Hypothyroidism|website=The Lecturio Medical Concept Library |access-date= 27 July 2021}}</ref>

==Terminology==
The term ''cretin'' was originally used to describe a person affected by this condition, but, as with words such as ''[[Spastic (word)|spastic]]'' and ''[[lunatic]]'', it underwent [[pejoration]] and is now considered derogatory and inappropriate.<ref>{{cite book|last1=Taylor|first1=Robert B.|title=White Coat Tales: Medicine's Heroes, Heritage, and Misadventures|date=2008|publisher=Springer|location=New York|isbn=978-0-387-73080-6|page=83|url=https://books.google.com/books?id=aNLk6ArybNoC&q=cretin%20cretinism%20pejorative&pg=PA83}}</ref> ''Cretin'' became a medical term in the 18th century, from an [[Occitan language|Occitan]] and an [[Alps|Alpine]] [[French language|French]] expression, prevalent in a region where persons with such a condition were especially common (see below); it saw wide medical use in the 19th and early 20th centuries, and was a "tick box" category on Victorian-era census forms in the UK. The term spread more widely in popular English as a markedly derogatory term for a person who behaves stupidly. Because of its pejorative connotations in popular speech, current usage among health care professionals has abandoned the noun "cretin" referring to a person. The noun ''cretinism'', referring to the condition, still occurs in medical literature and textbooks but its use is waning.<!--Lit searches in PubMed and other databases bear out this fact. ICD-10 provides an example of the nosologic categorization at E00.9 with "Approximate Synonyms: congenital iodine deficiency syndrome, endemic cretinism".-->{{citation needed|date=May 2022}}

The etymology of ''cretin'' is uncertain. Several hypotheses exist. The most common derivation provided in English dictionaries is from the Alpine French dialect pronunciation of the word ''Chrétien'' ("(a) [[Christians|Christian]]"), which was a greeting there. According to the ''[[Oxford English Dictionary]]'', the translation of the French term into "human creature" implies that the label "Christian" is a reminder of the humanity of the affected, in contrast to brute beasts.<ref>{{cite web|url=http://dictionary.oed.com/cgi/entry/50053852 |title=cretin |work=Oxford English Dictionary |access-date=11 December 2005 }}{{dead link|date=June 2016|bot=medic}}{{cbignore|bot=medic}}</ref> Other sources suggest that ''Christian'' describes the person's "Christ-like" inability to sin, stemming, in such cases, from an incapacity to distinguish right from wrong.<ref>{{cite web | last = Brockett | first = Linus P | url = http://www.disabilitymuseum.org/lib/docs/1385.htm | title = Cretins And Idiots | work = [[The Atlantic Monthly]] | date = Feb 1858 | access-date = 11 December 2005 }}</ref><ref>{{cite book | title = Robbins and Cotran – Pathologic basis of disease 8/E | location = Philadelphia, PA | publisher = Sauders Elsevier | year = 2004 }}</ref>

Other speculative etymologies have been offered:
* From ''creta'', Latin for ''chalk'', because of the [[pallor]] of those affected.
* From ''cretira'', [[Graubünden|Grison]]-[[Romansh language|Romanche]] ''creature'', from Latin ''creatus''.
* From ''cretine'', French for ''alluvium'' (soil deposited by flowing water), an allusion to the condition's suspected origin in inadequate soil.<ref>{{cite book | first = VC | last = Medvei | title = The History of Clinical Endocrinology | location = Pearl River, New York | publisher = Parthenon Publishing Group | year = 1993 }}</ref>

== See also ==
*[[Moron (psychology)]]

==References==
{{Reflist}}

== External links ==
{{Commons category-inline}}
{{Medical resources
|  DiseasesDB     = 6612
|  ICD11          = {{ICD11|5A00.04}}
|  ICD10          = {{ICD10|E00}}
|  ICD9           = {{ICD9|243}}
|  ICDO           =
|  OMIM           =
|  MedlinePlus    =
|  eMedicineSubj  = ped
|  eMedicineTopic = 501
| meshName        = Cretinism
| meshNumber      = C05.116.099.343.347
}}

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[[Category:Congenital disorders]]
[[Category:Thyroid disease]]
[[Category:Endocrine-related cutaneous conditions]]