[Study of the relation between Cx31 gene and hereditary hearing impairment].
OBJECTIVE
To study the relation between hereditary nonsyndromic hearing impairment (NSHI) in Chinese and mutation in Connexin 31 (Cx31) gene and to explore the pathogenic mechanism.


METHODS
Forty-seven pedigrees with hereditary NSHI, 38 Children with sporadic NSHI and cases of control were collected in present studies. The coding sequence of Cx31 gene was amplified by polymerase chain reaction (PCR), screened by denaturing high-performance liquid chromatography (DHPLC) and confirmed by direct sequencing.


RESULTS
The mutation rate of heterozygous mutation C --> T at position 798 of Cx31 cDNA in patient group and in control were 14.1% (12/85) and 1% (1/100) respectively. Significant difference was found between the two group (P < 0.01). Heterozygous mutation G --> A at position 580 of GJB3 cDNA, which results in a missense mutation (A194T), was found in two members of one pedigree with autosomal dominant NSHI. The mutation was not found in numbers with normal hearing of this pedigree and controls. Heterozygous mutation G --> A at position 250 of Cx31 cDNA was found in one child with sporadic congenital NSHI. In our previous studies, Cx26 gene mutations have been screened among the patient with hereditary NSHI and sporadic NSHI and the control of our test, and two Cx26 gene mutations were found in two pedigrees. But the two NSHI pedigrees which were confirmed to have Cx26 gene mutation were not found to have Cx31 mutation. The patient and the control which were confirmed to have Cx31 gene mutations were not found to have Cx26 mutations.


CONCLUSIONS
Cx31 gene was associated with nonsyndromic hearing impairment There was no cross and cooperative effect between Cx26 gene and Cx31 gene.
Gao
Wei-Hua
WH
Department of Otorhinolaryngology Head and Neck Surgery, PeKing University First Hospital, Beijing 100034, China. gaohz@263.net
Ke
Xiao-Mei
XM
Liu
Yu-He
YH
Zhu
Ping
P
Pan
Kai-Feng
KF
D000293:Adolescent; D044466:Asian People; D002648:Child; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D004252:DNA Mutational Analysis; D003638:Deafness / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D010375:Pedigree
D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26; C068044:GJB3 protein, human