In a recently published article titled “Dwarfism with joint laxity in Friesian horses is associated with a splice site mutation in B4GALT7”, a group of researchers indicated that they had “localized the genetic cause of the dwarfism by a genome wide approach to a 3 Mb region on the p-arm of equine chromosome 14. The DNA of two dwarfs and one control Friesian horse was sequenced completely and we identified the missense mutation” “that cosegregated with the phenotype in all Friesians analyzed.” They then observed that a similar mutation in humans is “associated with Ehlers-Danlos syndrome progeroid type 1 and Larsen of Reunion Island syndrome. Growth retardation and ligamentous laxity are common manifestations of these syndromes.” They conclude by stating that “crosses between carriers can be prevented by screening breeding horses for the B4GALT7 mutation and the dwarfism trait could thus be eliminated from the breed.”
Relevance: The more we understand and can identify the exact location of a mutation for a genetic disease, the more reliable our genetic test becomes. This is a very important step in the overall goal of decreasing genetic disease in the Friesian breed by breeding with knowledge of the genetic status of both stallion and mare.
Article: Leegwater et al. Dwarfism with joint laxity in Friesian horses is associated with a splice
site mutation in B$GALT7. BMC Genomics (2016) 17:839. DOI 10.1 186/s12864-016- 3186-0.