KIT’ing Around

Familial progressive hyperpigmentation (FPH), also known as melanosis universalis hereditaria, is a rare disorder characterized by congenital hyperpigmentation. Investigators in Shanghai undertook a genome-wide scan in a six-generation Chinese family with FPH and found significant evidence linking the FPH-responsible gene to chromosome 12q21.31-q23.1.

Affected individuals showed hyperpigmentation of the hands, palms, limbs, face, neck, trunk, and soles. Biopsy of the hyperpigmented skin demonstrated a significant increase in the number of melanocytes and in melanin content in the basal keratinocytes, as well as a slight increase in the size of melanocytes. Because the KIT ligand gene (KITLG) falls within the region of linkage, and, given its…