Study of mtDNA 12S rRNA A1555G, GJB2, GJB3 gene mutation in Uighur and Han people with hereditary nonsyndromic hearing loss in Xinjiang / 中华耳鼻咽喉头颈外科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study mtDNA, GJB2, GJB3 and determine gene mutation situs and frequency in Uighur and Han people with hereditary nonsyndromic hearing loss, and to compare the differences of gene mutation situs and frequency between Uighur and Han people.</p><p><b>METHODS</b>Blood samples were obtained from 93 patients (43 Uygur and 50 Han) with hereditary non-syndromic hearing loss and 110 normal people (56 Uygur and 54 Han). Genomic DNA was extracted from isolated leukocytes, and amplified by polymerase chain reaction (PCR). PCR products of GJB3 were sequenced directly; while PCR products of mitochondrial DNA 12S rRNA A1555G point mutations were analyzed by PCR-Alw26I digestion, and positive ones were further sequenced. GJB2 genes of 83 patients (43 Uygur and 40 Han) with hereditary non-syndromic hearing loss and 98 normal people (46 Uygur and 52 Han) were directly sequenced.</p><p><b>RESULTS</b>Among GJB3 genes of 93 patients, 2 cases of 33C-T, 2 cases of of 766G-A, 7 cases of 357C-T, and 4 cases of 798C-T were detected. Mitochondrial DNA 12SrRNA A1555G mutation was detected in 8 patients (2 Uygur and 6 Han). Nine kinds of base changes of GJB2 were detected 109G-A, 233-235delC, 79G-A, 196G-A, 341A-G, 564G-A, 380G-A, 71G-A, and 35delG. In the control group, detected GJB3 mutations included 4 cases of 357C-T, 5 cases of 798C-T, and 2 cases of 93C-T; while 9 kinds of base changes of GJB2 were detected 341A-G, 380G-A, 457G-A, 79-GA, 109G-A, 281A-G, 21G-T, 171G-T, and 368C-A. For mtDNA 12SrRNA A1555G, the difference between study group of and control group of Han people was statistically significant (P < 0.05). For GJB2 mutation 79G-A, the difference between study group and control group was statistically significant (P < 0.05) in both Uygur and Han people; while for GJB2 mutation 341A-G, the difference in study group between Uygur and Han people was statistically significant (P < 0.05). And for GJB3 mutation 798C-T, the difference was statistically significant both between study group and control group, and between Uygur and Han people (P < 0.05).</p><p><b>CONCLUSIONS</b>In Xinjiang, mutation rate was high for mtDNA 12SRNA A1555G. while GJB3 gene mutations were not the main cause of the hereditary nonsyndromic hearing loss. There were certain ethnic and geographical characteristics of GJB2and GJB3 mutations.</p>