We were pleased to see the results of Marlin et al1 in the article "Connexin 26 Gene Mutations in Congenitally Deaf Children," which appeared in the August 2001 issue of the ARCHIVES. Their results confirm those of our previously published study demonstrating that the M34T allele of connexin 26 (GJB2) is unlikely to be a recessive mutant allele causing DFNB1 deafness.2 However, their statement that they " . . . report herein for the first time, to our knowledge, that 2 subjects (parents of deaf children) who were compound heterozygotes (M34T/35delG) had normal hearing" is misleading. Although the statement appears to restrict their conclusion to the M34T/35delG genotype, its wording and the context of its discussion lay broader claim to the idea that M34T is not a recessive deafness allele. They do not refer to our study published nearly 1 year prior in September 2000 (electronic publication in July 2000), which was the first (and heretofore only) to show normal or near-normal auditory function associated with compound heterozygosity for M34T in trans with a known DFNB1 deafness allele, 167delT.2 Although our 47-year-old subject had presbycusic threshold elevations at 6 and 8 kHz, they were less than 15 dB above the 90th percentile value for age- and sex-matched normal control individuals, and our conclusion was that M34T is not a recessive mutant allele associated with deafness.2,3 It is worth noting that the individual with the compound heterozygous M34T/167delT genotype2 had normal hearing according to the pure-tone average (0.5, 1, and 2 kHz) criterion used by Marlin et al.1 It is unfortunate that audiometric data were not presented to confirm the normal hearing status of their M34T/35delG compound heterozygotes.1 We were gratified that the accompanying editorial written by Dr Smith4 accurately represented the relevant published literature.
Griffith AJ, Friedman TB. Auditory Function and the M34T Allele of Connexin 26. Arch Otolaryngol Head Neck Surg. 2002;128(1):94. doi: