Pupo Altair Cadrobbi, Pirana Sulene, Spinelli Mauro, Lezirovitz Karina, Netto Regina C Mingroni, Macedo Lisandra S
PhD in Communication Disorders at UNIFESP, Head of Department at speech and hearing therapy clinic - PUC/SP.
PhD in Medicine at Universidade de São Paulo, Associate Professor at the Speech and Hearing Therapy School at PUC-SP.
Braz J Otorhinolaryngol. 2008 Sep-Oct;74(5):786-789. doi: 10.1016/S1808-8694(15)31392-6.
We hereby report on the audiological and genetic findings in individuals from a Brazilian family, with the following mitochondrial mutation A1555G in the 12SrRNA gene (MT-RNR-1). Nine individuals underwent speech, audiologic (tonal audiometry and logoaudiometry) and genetic evaluations. Eight individuals among the A1555G carriers were affected by hearing impairment and one person had normal hearing thresholds till the end of the present study. The audiologic evaluation results indicated normal hearing thresholds all the way to bilateral profound hearing loss with post-lingual onset and variable configuration. Two affected siblings presented progressive hearing loss. It was impossible to precise the time of hearing loss onset; however, the impairment was present in both children and adults. The genetic study revealed the A1555G mitochondrial mutation in the 12SrRNA gene. Given the prevalence of mitochondrial mutations as a cause of hearing loss, it is fundamental to perform the etiopathologic diagnosis in order to postpone the onset or avoid hearing impairment progression. This kind of hearing impairment represents a challenge to the professionals since there are no physical traits that indicate genetic transmission.
我们在此报告一个巴西家庭中个体的听力学和遗传学研究结果，该家庭存在12SrRNA基因（MT-RNR-1）中的线粒体突变A1555G。九名个体接受了言语、听力学（纯音听力计检查和言语测听）及遗传学评估。A1555G携带者中有八人患有听力障碍，一人在本研究结束时听力阈值正常。听力学评估结果显示，从正常听力阈值到双侧极重度听力损失，呈语后起病且类型多样。两名受影响的兄弟姐妹表现出进行性听力损失。无法精确确定听力损失的起始时间；然而，儿童和成人中均存在这种损害。遗传学研究揭示了12SrRNA基因中的A1555G线粒体突变。鉴于线粒体突变作为听力损失原因的普遍性，进行病因诊断对于推迟发病或避免听力障碍进展至关重要。这种听力障碍对专业人员来说是一项挑战，因为没有表明遗传传递的身体特征。
