[GJB2 gene mutation in deaf patients].
OBJECTIVE
To detect the GJB2 gene mutation in patients with autosomal-recessive deafness, and analyze the relationship between clinical phenotype and gene mutation.


METHODS
Forty-two patients were examined clinically by pure tone audiometry, acoustic impedance and auditory brainstem response. The complete coding region of the GJB2 gene was amplified by polymerase chain reaction (PCR) and the PCR products were subjected to automatic DNA sequencing.


RESULTS
Two cases had homozygous mutation of 235delC. One of them had sensorineural hearing loss while the other had mixed hearing loss. Heterozygous mutation of 176del16bp was detected in a pair of twins who had mixed hearing loss. The 109G to A, 79G to A and 341A to G mutations were observed in both the patients and the controls.


CONCLUSIONS
Homozygous 235delC mutation is one of the pathogeni c mutations which could occur in patients with mixed hearing loss. The heterozygous 176del16bp mutation combined with environmental factor may cause hearing loss. The 109G to A, 79G to A and 341A to G variants were considered to be polymorphisms of the GJB2 gene.
The Second Affiliated Hospital, Jinan University School of Medicine, 518020 People's Republic of China.
Zhi-yong
ZY
Xu
Guo-feng
GF
Gao
Chang
C
Liu
Yu-hua
YH
Hu
Yi
Y
Lin
Ruan-zhang
RZ
Zhang
Ming
M
Liu
Sha-yan
SY
Wang
D000328:Adult; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D004272:DNA, Mitochondrial; D003638:Deafness / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005820:Genetic Testing; D034381:Hearing Loss / Q000235:genetics*; D006319:Hearing Loss, Sensorineural / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D016254:Mutagenesis, Insertional; D009154:Mutation; D019986:Persons with Hearing Disabilities; D011110:Polymorphism, Genetic; D017384:Sequence Deletion
D017630:Connexins; D004272:DNA, Mitochondrial; C000607042:GJB2 protein, human; D000072259:Connexin 26