Identification of 605ins46, a novel GJB2 mutation in a Japanese family

Connexin 26 gene (GJB2) mutations are known to be responsible for a significant portion (30–80%) of autosomal recessive congenital severe to profound deafness. More than 60 recessive mutations in GJB2 have been reported and most consist of point mutations of a nucleotide. We report here a novel insertional GJB2 mutation consisting of a long repetitive nucleotide sequence. As compound heterozygotes of this mutation with 235delC express sensorineural hearing loss of variable severity, further analysis of the phenotype–genotype relationship is required.