Editing Sphynx cat (section)

==Genetics and breeding==
Other hairless breeds may have body shapes or temperaments that differ from those of Sphynx standards. There are, for example, new hairless breeds, including the [[Don Sphynx]] and the [[Peterbald]] from Russia, which arose from their own spontaneous gene mutations. The standard for the Sphynx differs between cat associations such as [[The International Cat Association]] (TICA), [[Fédération Internationale Féline]] (FIFE) and [[Cat Fanciers' Association]] (CFA).

=== Breeding ===
In 2010, DNA analysis confirmed that Sphynx hairlessness was produced by a different [[allele]] of the same [[gene]] that produces the short curly hair of the [[Devon Rex]] (termed the "re" allele), with the Sphynx's allele being [[incompletely dominant]] over the Devon allele and both being recessive to the [[wild type]].<ref name=":4">{{Cite journal|last1=Gandolfi|first1=Barbara|last2=Outerbridge|first2=Catherine A.|last3=Beresford|first3=Leslie G.|last4=Myers|first4=Jeffrey A.|last5=Pimentel|first5=Monica|last6=Alhaddad|first6=Hasan|last7=Grahn|first7=Jennifer C.|last8=Grahn|first8=Robert A.|last9=Lyons|first9=Leslie A.|date=October 2010|title=The naked truth: Sphynx and Devon Rex cat breed mutations in KRT71|journal=Mammalian Genome|volume=21|issue=9–10|pages=509–515|doi=10.1007/s00335-010-9290-6|issn=0938-8990|pmc=2974189|pmid=20953787}}</ref> Other associations may vary, and the [[Russian Blue]] is a permitted outcross in the [[Governing Council of the Cat Fancy]] (GCCF).<ref>{{cite web |title=Sphynx Registration Policy |url=https://www.gccfcats.org/Portals/0/BreedRegPols/Sphynx%20Registration%20Policy%20updated%202017.pdf?ver=2017-11-09-125944-257 |publisher=Sphynx Breed Advisory Committee |access-date=30 October 2019 |date=2017}}</ref> 

=== Genetics ===
The Sphynx's distinctive hairlessness is primarily due to a mutation in the KRT71 gene, which also affects other breeds, such as the Devon Rex and Selkirk Rex, albeit with different outcomes. This gene is responsible for the keratinization of the hair follicle. In the Sphynx, the mutation, known as "hr", leads to a complete loss of function, damaging the structure of the hair. Normally, KRT71 helps produce strong hair that is securely anchored to the skin. However, due to the "hr" mutation, the hair of Sphynx cats lacks a solid root or bulb, making it extremely weak. Consequently, the hair is fragile and loosely attached, causing it to fall out easily and contributing to the breed's nearly hairless appearance.<ref name=":4" /> Sphynx cats may still retain very soft, short hair on parts of their body, such as the nose, tails, and toes, but overall, their coat is significantly reduced and lacks the typical structure seen in other cats.<ref name=":4" /> 

In the Devon Rex mutation, a residual activity of the protein still exists.<ref name=":4"/> The Selkirk Rex [[allele]] (sadr) is dominant over the wild type gene, which is dominant over the Devon Rex allele (re) and the Sphynx (hr), which forms an allelic series of : KRT71SADRE > KRT71+ > KRT71re > KRT71hr.<ref name="splice variant">{{cite journal |last1=Gandolfi |first1=B. |last2=Alhaddad |first2=H. |last3=Joslin |first3=S. E. |last4=Khan |first4=R. |last5=Filler |first5=S. |last6=Brem |first6=G. |last7=Lyons |first7=L. A. |year=2000 |title=A splice variant in KRT71 is associated with curly coat phenotype of Selkirk Rex cats |journal=Scientific Reports |volume=3 |pages=2000 |doi=10.1038/srep02000 |pmc=3683669 |pmid=23770706}}</ref>

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File:Cat Sphynx. Kittens. img 48.jpg|alt=Sphynx mother with kittens|Sphynx mother with kittens
File:2 week-old Female Sphynx (Suki).jpg|Two-week-old Sphynx kitten
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