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

The study investigates chronic progressive lymphoedema (CPL), a disabling condition common in draft horse breeds like Friesian horses, and explores its potential genetic components and possible predisposing physical traits.

Objective of the Research

• The main goal of this research was to determine whether a genetic component and a predisposing phenotype account for the high incidence of CPL in Friesian horses.

Methodology

• For this genomic study, a total of 45 horses were utilized, 26 of which were affected by the condition, and 19 served as controls.
• Body measurements were taken from 37 horses; including 28 affected and nine control Friesian horses.
• The researchers employed an Axiom® Equine Genotyping Array for the genome-wide association study (GWAS), which assessed a total of 307,474 single nucleotide polymorphisms (SNPs).
• Measurements such as height, weight, and seven different measurements related to the horse’s leg were collected and compared between the groups.

Results

• The research did not uncover significant associations through the GWAS.
• However, statistically significant differences (P < 0.05) were observed when comparing the gaskin length measurements (part of the horse's leg) between horses affected by CPL and the control group.

Conclusions

• The research identified that the potential genetic contribution to CPL in Friesian horses is complex and may be influenced by other SNP-associated factors.
• The finding of increased gaskin length in the CPL-affected horses suggests that this may be a physical trait that makes these horses more prone to developing the condition.