SLC26A4基因IVS7-2A>G突变在中国不同地区和民族重度感音聋患者中分布频率的观察

Frequency of SLC26A4 IVS7-2A>G mutation in patients with severe to profound hearing loss from different area and ethnic group in China

目的进行全国范围的 SLC26A4基因 IVS7-2 A>G 突变的分子流行病学调查,为大前庭水管综合征的快速筛查和临床基因诊断提供证据。方法应用自主研制的 SLC26A4基因 IVS7-2A>G 突变检测试剂盒对来自全国不同省市的1979例散发的非综合征性聋患者进行 IVS7-2 A>G 突变筛查,比较不同地区、民族的 IVS7-2 A>G 突变携带频率。结果在中国大陆不同地区1979例耳聋患者中发现 SLC26A4 IVS7-2A>G 纯合突变90例,杂合突变155例,总的携带率12.38%。不同地区间的携带率比较差别有统计学意义(x^2=34.4899,P<0.05),华中地区最高,西南地区最低;不同民族比较差别有统计学意义(x^2=35.4456,P<0.05),汉族携带率最高为13.88%,藏族最低携带率为0。不同民族间的两两比较汉族与我国西部地区的少数民族比较差别有统计学意义,西部地区少数民族之间比较差别无统计学意义。结论中国非综合征性聋患者中 IVS7-2A>G 突变携带率相当高,中国不同地区、民族间 SLC26A4基因 IVS7-2 A>G 突变可能存在明显的差异,SLC26A4的基因诊断可作为大前庭水管综合征的快速筛查方法。

Objective To carry out molecular epidemiology study of SLC26A4 IVS7-2 A 〉 G mutation in large Chinese deaf population and to provide evidence for fast screening and gene diagnosis of enlarged vestibular aqueduct syndrome（ EVAS）. Methods A total of 1979 patients with non-syndromic hearing loss（ NSHL）underwent questionnaire and PCR for IVSA 〉 G mutation detection of SLC26A4 gene. Results All 245 patients （ 12. 38% ） with homozygotous and heterozygotous IVS7-2 A 〉 G mutation were found among the 1979 NSHL. It showed statistically significant difference among north and northeast, northwest, east and southeast, southwest and central area in China. （ X^2 = 34. 4899, P 〈 0. 05 ）. Carrier frequency of the central area（27. 52% ） was notably higher than southwest area（6. 69% ）. The IVS7-2 A 〉 G mutation was most frequently found in Han deaf groups （ 13. 88% ）. Tibetan, Hui, and other western minorities were lower than Han deaf population（ X^2 = 35.4456,P 〈 0.05）. Conclusions A high SLC26A4 IVS7-2 A 〉 G mutation frequency for deafness in Chinese patients was found. Detection of the pathogenic mutations was bringing the possibility to detect EVAS at an early stage. Moreover, it might help to establish diverse diagnostic strategies toward differently ethical deaf population in different region of China.