[Analysis of genetic mutation in patients with nonsyndromic hearing loss received cochlear implant].
OBJECTIVE
To investigate the prevalence of mutations of the gap junction protein (GJB) 2 and mitochondria 12SrRNA in patients with nonsyndromic hearing loss who received cochlear implant.


METHODS
Genomic DNA was extracted from the peripheral blood samples obtained from 100 Chinese patients who had received cochlear implantation, 96 with prelingual hearing loss and 4 with postlingual hearing loss, all very severe. Sixteen of the 100 patients had the history of application of aminoglycosides, among which 12 were with prelingual hearing loss and 4 with postlingual hearing loss. PCR was performed and the products were sequenced by automated DNA sequencer.


RESULTS
GJB2 mutations were detected in 34 of the 100 cochlear implant recipients (34%), all with prelingual hearing loss, among which 27 (27%) had 235delC mutation. Among the 16 patients who had used aminoglycosides, two had the mutation A1555G, and one carried the mitochondrial genetic mutation delT961Cn.


CONCLUSIONS
Mutation of GJB2 gene is the major cause of deafness in cochlear implant recipients, with a high frequency of 235delC mutation. Mitochondria genetic mutation A1555G is the common form of mutation in postlingual deafness with a history of aminoglycoside injection.
Tian
Yong-sheng
YS
Department of Otorhinolaryngology, Peking Union Medical College Hospital, Peking Union Medical College, Beijing 100730, China.
Chen
Xiao-wei
XW
Cao
Ke-li
KL
Chen
Dong-ye
DY
Zuo
Jin
J
Fang
Fu-de
FD
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D019929:Cochlear Implantation; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D034381:Hearing Loss / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009154:Mutation; D012335:RNA, Ribosomal / Q000235:genetics
D017630:Connexins; D004272:DNA, Mitochondrial; C000607042:GJB2 protein, human; D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S; D000072259:Connexin 26