Jiang Hua, Chen Jia, Li Ying, Lin Peng-Fang, He Jian-Guo, Yang Bei-Bei
Department of Otolaryngology, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Zhejiang, China.
Department of Otolaryngology, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Zhejiang, China.
Braz J Otorhinolaryngol. 2016 Jul-Aug;82(4):391-6. doi: 10.1016/j.bjorl.2015.06.006. Epub 2015 Nov 5.
Several mitochondrial DNA mutations have been reported to be associated with nonsyndromic hearing loss in several families. However, little is known about the prevalence of these mutations in sporadic patients with nonsyndromic sensorineural hearing loss.
The purpose of our study was to investigate the incidence of these mitochondrial DNA mutations in such population.
A total of 178 sporadic patients with nonsyndromic sensorineural hearing loss were enrolled in this study. Genomic DNA was extracted from the peripheral blood sample. We employed the SNaPshot(®) sequencing method to detect five mitochondrial DNA mutations, including A1555G and A827G in 12S rRNA gene and A7445G, 7472insC, and T7511C in tRNA(Ser(UCN)) gene. Meanwhile, we used polymerase chain reaction and sequenced the products to screen GJB2 gene mutations in patients carrying mitochondrial DNA mutations.
We failed to detect the presence of A1555G mutation in 12S rRNA gene, and of A7445G, 7472insC, T7511C mutations in tRNA(Ser(UCN)) gene in our population. However, we found that 6 patients (3.37%) were carriers of a homozygous A827G mutation and one of them also carried homozygous GJB2 235delC mutation.
Our findings in the present study indicate that even in sporadic patients with nonsyndromic sensorineural hearing loss, mitochondrial DNA mutations might also contribute to the clinical phenotype.
据报道，几个家族中的几种线粒体DNA突变与非综合征性听力损失有关。然而，对于这些突变在散发性非综合征性感音神经性听力损失患者中的患病率知之甚少。
我们研究的目的是调查这些线粒体DNA突变在该人群中的发生率。
本研究共纳入178例散发性非综合征性感音神经性听力损失患者。从外周血样本中提取基因组DNA。我们采用SNaPshot(®)测序方法检测5种线粒体DNA突变，包括12S rRNA基因中的A1555G和A827G以及tRNA(Ser(UCN))基因中的A7445G、7472insC和T7511C。同时，我们使用聚合酶链反应并对产物进行测序，以筛查携带线粒体DNA突变患者的GJB2基因突变。
我们在研究人群中未检测到12S rRNA基因中的A1555G突变以及tRNA(Ser(UCN))基因中的A7445G、7472insC、T7511C突变。然而，我们发现6例患者（3.37%）是纯合A827G突变的携带者，其中1例还携带纯合GJB2 235delC突变。
我们在本研究中的发现表明，即使在散发性非综合征性感音神经性听力损失患者中，线粒体DNA突变也可能对临床表型有影响。
