Editing Scottish Fold (section)

==Health==
[[Polycystic kidney disease]] (PKD) is prevalent in the Scottish Fold.<ref>{{cite journal | last=Shitamori | first=Fumitaka | last2=Nonogaki | first2=Ayaka | last3=Motegi | first3=Tomoki | last4=Matsumoto | first4=Yuki | last5=Sakamoto | first5=Mika | last6=Tanizawa | first6=Yasuhiro | last7=Nakamura | first7=Yasukazu | last8=Yonezawa | first8=Tomohiro | last9=Momoi | first9=Yasuyuki | last10=Maeda | first10=Shingo | title=Large-scale epidemiological study on feline autosomal dominant polycystic kidney disease and identification of novel PKD1 gene variants | journal=Journal of Feline Medicine and Surgery | publisher=SAGE Publications | volume=25 | issue=7 | year=2023 | issn=1098-612X | doi=10.1177/1098612x231185393 | page=| doi-access=free | pmc=10812055 }}</ref> A study in Japan of cats suspected to have kidney problems found that 54% of tested Scottish Fold cats had the PKD1 mutation, which is responsible for PKD.<ref>{{cite journal |last1=Sato |first1=R. |last2=Uchida |first2=N. |last3=Kawana |first3=Y. |last4=Tozuka |first4=M. |last5=Kobayashi |first5=S. |last6=Hanyu |first6=N. |last7=Konno |first7=Y. |last8=Iguchi |first8=Aiko |last9=Yamasaki |first9=Yayoi |last10=Kuramochi |first10=Konomi |last11=Yamasaki |first11=Masahiro |title=Epidemiological evaluation of cats associated with feline polycystic kidney disease caused by the feline PKD1 genetic mutation in Japan |journal=The Journal of Veterinary Medical Science |date=2019 |volume=81 |issue=7 |pages=1006–11 |pmid=31155548 |doi=10.1292/jvms.18-0309 |pmc=6656814 }}</ref>

A study in Japan found two genes linked to [[hypertrophic cardiomyopathy]] in the Scottish Fold population.<ref>{{cite journal | last=Akiyama | first=Noriyoshi | last2=Suzuki | first2=Ryohei | last3=Saito | first3=Takahiro | last4=Yuchi | first4=Yunosuke | last5=Ukawa | first5=Hisashi | last6=Matsumoto | first6=Yuki | title=Presence of known feline ALMS1 and MYBPC3 variants in a diverse cohort of cats with hypertrophic cardiomyopathy in Japan | journal=PLOS One | publisher=Public Library of Science (PLoS) | volume=18 | issue=4 | date=2023-04-18 | issn=1932-6203 | doi=10.1371/journal.pone.0283433 | doi-access=free | page=e0283433| pmc=10112785 }}</ref>

===Osteochondrodysplasia===
A defect of [[Ear|aural]] [[cartilage]] gives the Scottish Fold the characteristic appearance. This cartilage defect is caused by an [[autosomal]] [[dominant gene]]. This mutation also causes a shortened and stiff tail that lacks rigidity. It also causes a [[skeletal dysplasia]] known as osteochondrodysplasia. All Scottish Fold cats develop [[arthritis]]: [[heterozygous]] cats develop a progressive form of arthritis and [[homozygous]] cats develop a severe arthritis much quicker than heterozygous cats.  Near the [[Hock (anatomy)|tarsal]] and [[metatarsal]] joints [[exostosis]] forms in kittens with the condition. [[Endochondral ossification]] is retarded and [[metatarsal]] and [[metacarpal]] bones fail to reach full length and develop abnormally result in improper shapes for the bones. Treatment is possible with either [[palliative radiation]] and surgery, which can be either excising the exostoses or a bilateral [[pantarsal arthrodesis]] can alleviate [[lameness]]; however, given all fold cats will become affected the only solution is the cessation of breeding of affected cats.<ref name="orthopaedics">{{cite book | last=Scott | first=Harry | last2=Marti | first2=Juan M | last3=Witte | first3=Philip | title=Feline Orthopaedics | publisher=CRC Press | publication-place=Boca Raton | date=August 2021 | isbn=978-1-4987-6497-1 | page=107}}</ref>

In a 2021 study,<ref>{{Cite journal |doi=10.1007/s00439-021-02337-5 |pmid=34406467 |title=Radiographical Survey of Osteochondrodysplasia in Scottish Fold Cats caused by the TRPV4 gene variant |date=2021 |last1=Rorden |first1=Chris |last2=Griswold |first2=Marilee C. |last3=Moses |first3=Nan |last4=Berry |first4=Clifford R. |last5=Keller |first5=G. Gregory |last6=Rivas |first6=Rudy |last7=Flores-Smith |first7=Helen |last8=Shaffer |first8=Lisa G. |last9=Malik |first9=Richard |journal=[[Human Genetics (journal)|Human Genetics]] |volume=140 |issue=11 |pages=1525–34 |s2cid=237198301}}</ref> four radiologists, [[Blinded experiment|blinded]] to the ear phenotype, assessed radiographs of 22 Scottish Fold/Straight cats. All cats were genotyped showing the heterozygous mutation in all folded ear cats but not in straight cats. Each reviewer gave on average the folded ear cats a worse "severity score", however the images showed much milder signs than previously published. The authors state that the severity of OCD in heterozygous cats is very variable and subtle. This could be due to other modifier genes or nurture (climate, diet, exercise). So it was shown that the least affected folded ear cat was given identical or less score than the highest rated straight ear cat.

In a 2020 case study,<ref>{{Cite journal |doi=10.1292/jvms.20-0299 |pmc=7804039 |pmid=33162427 |title=Osteochondrodysplasia in Scottish Fold cross-breed cats |date=2020 |last1=Takanosu |first1=Masamine |last2=Hattori |first2=Yuki |journal=The Journal of Veterinary Medical Science |volume=82 |issue=12 |pages=1769–72}}</ref> two Scottish Fold mixed cats with severe [[exostosis]] in the hind leg are described. Both cats were homozygous for the ''Trpv4'' mutation, assuming the parental cats had both the c.1024G>T mutation in the ''TrpV4'' gene. This reinforces the hypothesis that mostly homozygous Scottish Folds are severely affected.<ref>{{cite journal |pmid=18339089 |date=2008 |last1=Takanosu |first1=M. |last2=Takanosu |first2=T. |last3=Suzuki |first3=H. |last4=Suzuki |first4=K. |title=Incomplete dominant osteochondrodysplasia in heterozygous Scottish Fold cats |journal=The Journal of Small Animal Practice |volume=49 |issue=4 |pages=197–9 |doi=10.1111/j.1748-5827.2008.00561.x}}</ref> On the other hand it is concerning that still Scottish Fold cats are bred with each other,  also breeding with other cat strains with skeletal abnormalities ([[Munchkin cat|Munchkin]], [[American Curl]]) should be avoided.

In a large retrospective Australian study <ref>{{cite journal |vauthors=Velie BD, Milden T, Miller H, Haase B |title=An estimation of osteochondrodysplasia prevalence in Australian Scottish Fold cats: a retrospective study using VetCompass Data |journal=BMC Vet Res |volume=19 |issue=1 |pages=252 |date=November 2023 |pmid=38031079 |doi=10.1186/s12917-023-03811-0 |doi-access=free |pmc=10685627 }}</ref> over 30,000 patient records from veterinary clinics were searched for specific keywords to look for the occurrence of OCD in Scottish Fold cats. Of 1131 Scottish Folds, 12 were detected with OCD (1.1%) and 5.7% were suspected of OCD. 

In a study by Sartore et al.<ref>{{cite journal |vauthors=Sartore S, Moretti R, Piras LA, Longo M, Chessa S, Sacchi P |title=Osteochondrodysplasia and the c.1024G>T variant of TRPV4 gene in Scottish Fold cats: genetic and radiographic evaluation |journal=J Feline Med Surg |volume=25 |issue=12 |pages=1098612X231211763 |date=December 2023 |pmid=38055304 |doi=10.1177/1098612X231211763 |pmc=10811760 }}</ref>, in which folded-eared cats were genetically analyzed and only one specific gene variant (c.1024G>T) was examined, it was found that 1 out of 12 cats showed signs of OCD. The authors speculate that it is not just this mutation in the ''Trpv4'' gene that is responsible for the development of OCD.

Because heterozygous Scottish Folds also develop [[Progressive disease|progressive]] arthritis of varying severity, some researchers recommend abandoning the breeding of Fold cats entirely.<ref name="AustraliaVetJournal">{{cite journal |last1=Malik |first1=R. |last2=Allan |first2=G.S. |last3=Howlett |first3=C.R. |last4=Thompson |first4=D.E. |last5=James |first5=G. |last6=McWhirter |first6=C. |last7=Kendall |first7=K. |title=Osteochondrodysplasia in Scottish Fold cats |journal=[[Australian Veterinary Journal]] |date=February 1999 |volume=77 |issue=2 |pages=85–92 |pmid=10078353}}</ref><ref>{{cite web |url= http://www.vin.com/proceedings/Proceedings.plx?CID=WSAVA2003&PID=6652&O=Generic |title=Genetic Disorders of Cats |last=Malik |first=Richard |date=2003 |publisher=World Small Animal Veterinary Association |work=World Congress Proceedings, 2003 |access-date=20 December 2009}}</ref>