Chronic progressive lymphoedema in Friesian horses: suggestive phenotype of affected horses and genome-wide association study.

Abstract

BACKGROUND: Chronic progressive lymphoedema (CPL) is a disabling condition affecting various draft horse breeds, including Friesian horses. HYPOTHESIS: The high incidence of CPL in Friesian horses suggests a genetic component and a predisposing phenotype. ANIMALS: For the genomic study, 26 affected and 19 control horses were evaluated. Body measurements were taken from 28 affected and nine control Friesian horses. METHODS AND MATERIALS: Axiom&#xae; Equine Genotyping Array with a total of 307,474 single nucleotide polymorphism (SNPs) was used for the case/control genome-wide association study (GWAS). Height, weight and leg measurements (seven different body measurements) were obtained and compared between groups. RESULTS: No significant associations were identified with the GWAS. There were significant differences (P&#xa0;<&#xa0;0.05) in gaskin length measurements between CPL-affected horses and controls. CONCLUSION: The current study suggests that the potential genetic contribution to CPL in Friesian horses is complex and may include other SNP-associated factors. Significantly increased gaskin length of affected horses suggests a phenotype prone to developing CPL.