Waardenburg syndrome type II (WS2) is associated with syndromic deafness. A 
subset of WS2, WS2A, accounting for approximately 15% of patients, is attributed 
to mutations in the microphthalmia-associated transcription factor (MITF) gene. 
We examined the genetic basis of WS2 in a large Chinese family. All 9 exons of 
the MITF gene, the single coding exon (exon 2) of the most common hereditary 
deafness gene GJB2 and the mitochondrial DNA (mtDNA) 12S rRNA were sequenced. A 
novel heterozygous mutation c.[742_743delAAinsT;746_747delCA] in exon 8 of the 
MITF gene co-segregates with WS2 in the family. The MITF mutation results in a 
premature termination codon and a truncated MITF protein with only 247 of the 
419 wild type amino acids. The deaf proband had this MITF gene heterozygous 
mutation as well as a c.[109G>A]+[235delC] compound heterozygous pathogenic 
mutation in the GJB2 gene. No pathogenic mutation was found in mtDNA 12S rRNA in 
this family. Thus, a novel compound heterozygous mutation, 
c.[742_743delAAinsT;746_747delCA] in MITF exon 8 was the key genetic reason for 
WS2 in this family, and a digenic effect of MITF and GJB2 genes may contribute 
to deafness of the proband.