Blonds Have Less KIT Ligand

Many genome-wide association studies (GWAS) have focused on identifying genetic loci that determine hair pigmentation. Hair color is one of the most diverse, visible, and heavily modified of all human phenotypes, with deep cultural implications.

Guenther and colleagues studied rs12821256, a single nucleotide variation (SNV) in the human genome associated with blond hair in northern Europeans. Although the nearest gene was the KIT ligand, it was initially unclear how this variant might alter its function as the natural activator of the KIT receptor, a critical regulator of melanocyte migration and pigmentation. Transplanting the region of DNA containing rs12821256 into mice and into cells showed that the SNV functions as an enhancer of transc…