Test Detail

Test for the curly coat of the horse, which analyses the main variant in KRT25 and the modifier variant in SP6 associated with the presence or absence of hypotrichosis. It is complementary to, not a substitute for, clinical examination.

Applicable breed: Bashkir Curly, Curly Horse and other breeds with curly hair. Frequencies: limited data.

• Curly coat, ranging from soft waves to a tight, permanent curl.\n• It may be accompanied by hypotrichosis or hair loss depending on the alleles present.\n• Carriers of variants in both genes may show curl with hypotrichosis.

Curly hair was classically described with dominant inheritance (Crd). In 2017 Morgenthaler and colleagues identified a variant in KRT25, and in 2018 Thomer and colleagues described the epistatic interaction between KRT25 and SP6.

• Interpret KRT25 and SP6 together because of their epistatic effect.\n• In horses with hypotrichosis, assess cold management and skin protection.\n• Not all curly horses are explained by KRT25; if the phenotype does not match, consider other causes.\n• Selection for curl must not compromise hair coverage.

Curly hair has also been associated with a lower allergen load in some studies, which must not be confused with the absence of allergens. Hypotrichosis may require dermatological management.

1. Morgenthaler 2017, A missense variant in the coil1A domain of the keratin 25 gene is associated with the dominant curly hair coat trait (Crd) (PMID 29141579); OMIA:003039-9796.
2. Thomer 2018, An epistatic effect of KRT25 on SP6 is involved in curly coat in horses (PMID 29686323); OMIA:002175-9796.