New KIT mutations in patients with piebaldism.

BACKGROUND: Piebaldism is an autosomal dominantly inherited disorder characterized by congenital leukoderma, typically on the forehead, abdomen, and knees. The leukoderma is usually stable throughout life. KIT mutations have been demonstrated in about 75% of patients with piebaldism.

OBJECTIVES: To identify KIT mutations of the family with piebaldism and examine genotype-phenotype correlations in this disorder.

METHODS: PCR-direct-sequencing technique using genomic DNA from peripheral leukocytes.

RESULTS: We have studied 10 individuals within six piebaldism families and able to identify six novel mutations in the KIT gene in patients with piebaldism. These include four frameshift mutations: 142delG, 1768-1769delAG, 2139delC, 2246-2249delAAAG, and two missense mutations: M541L, Y870C.

CONCLUSIONS: These six new mutations are associated with phenotypes that are well in accordance with our knowledge of genotype-phenotype correlations in KIT.