Human piebaldism: relationship between phenotype and site of kit gene mutation.

Human piebaldism is a rare autosomal dominant disorder characterized by congenital depigmented patches of skin and hair. Piebaldism results from mutations of the kit proto-oncogene, which encodes a cell-surface receptor, tyrosine kinase, whose ligand is the stem/mast cell growth factor. We report four unrelated patients with piebaldism and consider the variations in phenotype in relation to the site of the kit gene mutation.