Adding evidence for a role of the SLITRK gene family in the pathogenesis of left displacement of the abomasum in Holstein-Friesian dairy cows

Left displacement of the abomasum (LDA) is a frequent disease in Holstein-Friesian cattle with a big economic impact in dairy farms. LDA is a multi-factorial disease and genetics is known to play a role (low to moderate estimated heritability). It is therefore of interest to look for genetic polymorphisms associated with LDA in order to find involved genes and clarify the pathogenesis of the condition. In a population of 62 Italian Holstein-Friesian cows, LDA cases and SNP genotypes were recorded, and a genome-wide association study (GWAS) was performed. A genetic signal of association with LDA was detected on BTA 12, within the sequence of the SLITRK5 gene. This gene is involved in neurological activities such as axonogenesis and synaptic transmission, and this may be related with abomasal hypomotility and atony, which are considered the primary causes of LDA. The results of this research suggest a role for the SLITRK5 gene, and more generally for all nearby genes of the SLITRK family, in the pathogenesis of LDA in dairy cattle. The involvement of the SLITRK gene family may lead to novel approaches for the prevention, diagnosis and therapy of LDA, and could also be used in enhanced selection schemes for healthier animals.