A NOVEL MUTATION IN THE MITF GENE CAUSES WAARDENBURG-SYNDROME TYPE-2

Mutations in the MITF gene on human chromosome 3 have been reported in families with Waardenburg Syndrome Type 2 (WS2), an autosomal dominan t disorder responsible for a large proportion of congenital hearing lo ss. We examined 16 families with WS2 for mutations in the MITF gene. I n one four-generation family, we found a novel two-base deletion in ex on 6 of the MITF gene at nucleotide position 699. This mutation introd uces a frame-shift and stop codon which leads to a truncation of the p rotein. This mutation is predicted to have phenotypic consequences not withstanding evidence of reduced penetrance and heterogeneity within the family studied.