西南地区母系遗传性耳聋家系的线粒体DNA分析

Mitochondrial DNA Mutations in Matrilineal Nonsyndromic Deafness Pedigrees of Southwest China

目的 检测 15 5 5 A→ G突变在西南地区母系遗传性非综合征性耳聋家系中的发生率 ,探讨其听力学特征 ,为建立相应的基因诊断方法提供依据。方法 对六个家系成员共 10 2人进行听力学评估 ,并收集每人的外周静脉血标本 ,提取 DNA,用 PCR- RFL P法 (Alw 2 6 限制性内切酶 )检测 15 5 5 A→ G突变。结果 听力损害的共同特点为双侧、对称性进行性耳蜗性聋 ,氨基甙类抗生素致聋 (AAID)家系 1、2所有母系成员共 17人有 15 5 5 A→ G突变 ,非 AAID家系 6母系成员 10人也有此突变。非母系成员及家系 3、4、5所有成员无此突变。结论 mt DNA15 5 5 A→ G突变是这类耳聋的遗传基础之一 ,而氨基甙类抗生素是其重要的环境因素。 15 5 5 A→ G突变在西南地区 AAID及非综合征性耳聋家系均有较高发生率。

Objective To identify the incidence of the 1555 A→G mutation and explore the audiological features of pedigrees with matrilineal non syndromic deafness in Southwest of China so as to provide the theoretical evidence for establishing the method of gene diagnosis. Methods Six pedigrees with 102 members were evaluated audiologically and clinically. DNA was extracted from their blood samples. All subjects were screened for mitochondrial DNA 1555 A→G mutation by Alw 26I restriction endonuclease digestion. Results Seventeen maternal relatives of aminoglycoside antibiotic induced deafness (AAID) pedigree 1 and pedigree 2, carried 1555 A→G mutation. 10 maternal relatives of Non AAID pedigree 6 also carried 1555 A→G mutation. No mutation was found among paternal relatives and pedigrees 3, 4 and 5. Conclusion The same audiological features of these pedigrees are : bilateral and symmetrical progressive sensorineural hearing loss with variable age of onset. The 1555 A→G mitochondrial mutation is one of the hereditary factors for this disorder.4 Aminoglycoside antibiotic plays an important role in developing deafness. The incidence of the 1555 A→G mutation in AAID and matrilineal non syndromic deafness pedigrees is fairly high. Screening for mitochondrial 1555 A→G mutation may be of great clinical use fulness.