Molecular genetic analysis of the ATP2A2 gene as candidate for chronic pastern dermatitis in German draft horses.

Chronic pastern dermatitis predominantly affects draft horses, and this condition is characterized by hyperkeratotic-hyperplastic dermal alterations. Chronic pastern dermatitis resembles the acral-hemorrhagic phenotype of Darier-White disease in humans. The ATP2A2 gene has been shown to be responsible for human Darier-White. Thus, we chose ATP2A2 on equine chromosome 8 (ECA8) as candidate for chronic pastern dermatitis in coldblood horses. A linkage analysis was performed in 10 paternal half-sib families consisting of 85 German coldblood horses using a microsatellite closely linked to ATP2A2, a microsatellite within intron 5, 3 single-nucleotide polymorphisms within intron 3 of ATP2A2, and 5 more distantly located flanking microsatellites on ECA8. These markers were clearly not linked to pastern dermatitis and so our data proved that ATP2A2 is not responsible for chronic pastern dermatitis of German coldblood horses.