Inheritance of hereditary equine regional dermal asthenia in Quarter Horses.
ABSTRACT To assess heritability and mode of inheritance for hereditary equine regional dermal asthenia (HERDA) in Quarter Horses.
1,295 horses with Quarter Horse bloodlines, including 58 horses affected with HERDA.
Horses were classified as affected or unaffected or as undetermined when data were insufficient to assess phenotype. Pedigree data were analyzed to determine the probable mode of inheritance. Heritability was estimated by use of Bayesian statistical methods.
Heritability (mean+/-SD) of HERDA was estimated to be 0.38+/-0.13, with both sexes having an equal probability of being affected. Results for evaluation of the pedigrees were consistent with a single Mendelian autosomal recessive mode of inheritance.
HERDA in Quarter Horses is an inherited disease, and affected horses are more likely to produce affected offspring. An autosomal recessive mode of inheritance should be considered by people making breeding decisions involving Quarter Horses when a first-degree relative has been confirmed with HERDA or has produced affected offspring. In addition, breeders whose horses have produced affected offspring can reduce the likelihood of producing affected horses in the future by avoiding inbreeding.
- The Veterinary record 02/2008; 162(1):20-2. DOI:10.1136/vr.162.1.20 · 1.63 Impact Factor
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ABSTRACT: In neonatal foals and young horses, both hereditary and acquired diseases can have skin lesions as the primary owner complaint. Cutaneous markers of disorders of young horses include coat color patterns (eg, lethal white foal syndrome and deafness syndrome in Paint horses or lavender foal syndrome in Arabian horses) as well as specific skin lesions (eg, skin sloughing due to junctional epidermolysis bullosa) that should alert equine practitioners and dermatologists alike to underlying disease processes. Diseases with skin manifestations range from those in which the skin is the primary organ affected (eg, skin that is easily stretched with hereditary equine regional dermal asthenia) to those for which dermatological lesions are secondary and resolve with treatment of the underlying disease (eg, syndrome of suspected immune-mediated ulcerative dermatitis). This review is primarily focused on disorders that are either hereditary or affect young horses in the first few weeks to years of life.Clinical Techniques in Equine Practice 12/2005; 4(4):314-323. DOI:10.1053/j.ctep.2005.10.006
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ABSTRACT: A Quarter Horse gelding presented with pathology consistent with hereditary equine regional dermal asthenia (HERDA) but without the familial association typically present with this disease. Grossly, lesions exhibited either a firm, scar-like appearance or a potential space between the superficial and deep dermis. Both lesioned and non-lesioned skin showed evidence of edema and collagen fragmentation, whereas lesions were also characterized by hemorrhage and inflammation. Genetic testing was performed by three independent laboratories, each using different methods to detect the mutation described in the PPIB gene, previously shown to be associated with HERDA. No mutations in the PPIB gene were revealed by genetic testing, either at the known location of the point mutation or at any other location in the coding sequence. These findings are suggestive of a diagnosis of HERDA or hyperelastosis cutis in the absence of the well-described, putatively causative mutation in the PPIB gene. We propose that, whereas HERDA refers specifically to a familial disease caused by a mutation in the PPIB gene, similar symptoms may in fact be caused by a syndrome resulting from either inherited or spontaneous mutations in any of a number of collagen-processing genes. We conclude that Ehlers-Danlos syndrome be diagnosed in horses of any breed with HERDA-like pathology without the causative mutation.Journal of Equine Veterinary Science 12/2013; 34(4). DOI:10.1016/j.jevs.2013.10.178 · 0.89 Impact Factor