| Abstract #40, Date 2/14/99, Session E1, Poster (J8) |
| Prevalent mutations in connexin 26 gene in sporadic and recessive non-syndromic deafness in Japanese population |
| *S. Usami, S. Abe, H. Shinkawa (Dept of Otorhinolaryngology, Hirosaki Univ Sch of Med, Hirosaki, Japan); M.D. Weston, P.M. Kelley, W.J. Kimberling (Dept of Genetics, Boys Town National Res Hosp, Omaha, NE, USA) |
The gene responsible for DNFB1 and DFNA3, connexin 26 (GJB2), was recently identified and more than 20 disease-causing mutations have been reported. Since there have been no reports regarding Cx26 mutations in Asian populations, it is an interesting question as to whether Cx26 mutations are also an important cause of nonsyndromic recessive hearing loss in the Japanese population. Whether the 35delG mutation is also the most common mutation found in Japanese is of importance. In the present study, we performed mutation screening for the Cx26 gene in recessive nonsyndromic deafness families and sporadic deafness patients. A DNA fragment containing the entire coding region was amplified using PCR. The PCR products were purified and sequenced by means of the ABI Prism BigDye Terminator Cycle Sequencing Ready Reaction Kit and an ABI sequencer 377 (Perkin Elmer Co., Ltd.). Three frequent mutations, 235delC, Y136stop, and R143W, were found to be important mutations associated with Japanese recessive nonsyndromic hearing loss. This spectrum of disease-causing mutations was also found in sporadic cases which are compatible with recessive non-syndromic hearing loss. Surprisingly, none has the 35delG mutation, known as the most common in many other ethnic groups. The present study indicated that different combinations of Cx26 mutations exist in, and are a significant cause of recessive non-syndromic hearing loss in the Japanese ethnic group. |