Hoof Wall Separation Disease (HWSD)
Gene or Region: SERPINB11
Reference Variant: -
Mutant Variant: C
Affected Breeds: Connemara
Research Confidence: High Confidence - Strong association and functional data in studied population
Explanation of Results: hwsd/hwsd = homozygous for Hoof Wall Separation Disease, trait expressed hwsd/n = heterozygous for Hoof Wall Separation Disease, carrier n/n = no variant detected
General Description
Hoof wall separation disease is characterized by separation and breakage of the dorsal hoof wall extending up from the sole. Affected ponies begin showing symptoms at less than 6 months of age, and often develop chronic laminitis. Frequent hoof trimming and glue on shoes can help manage the condition. Hoof wall separation disease is an autosomal recessive disorder, thus a pony must inherit two copies (HWSD/HWSD) to show symptoms. Ponies with only one allele (HWSD/n) are known as carriers due to their ability to produce affected offspring.
Gene Information
SERPINB11 is a serine protease inhibitor of unknown function. In normal horses, it is highly expressed in the corony band. However, the insertion associated with HWSD results in a premature stop codon, resulting in an incomplete protein and greatly decreased expression.
References
Finno CJ et al., “SERPINB11 frameshift variant associated with novel hoof specific phenotype in Connemara ponies.” (2015) PLoS Genet. 11: e1005122. PMID: 25875171
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