Discovery of Four New FGF5 Variants Causing Long Hair in the Dog

The study discovered four new FGF5 gene variants (Lh6-Lh9) linked to long hair in dogs, particularly Tibetan Mastiffs, which were not accounted for by previously known variants. The research involved 739 dogs, including 24 Tibetan Mastiffs and one mixed breed dog, with most exhibiting longer hair than expected. These variants significantly affect protein structure, as shown by PolyPhen-2 and SIFT analyses, and are located near crucial β sheets of the FGF5 protein. Although less common than known alleles, these variants enhance phenotype predictions for certain breeds and may exist in other large breeds like the Anatolian Shepherd. Further research with larger samples is needed to assess their prevalence across breeds.