Tamagawa Y, Kitamura K, Hagiwara H, Ishida T, Nishizawa M, Saito T, Iwamoto Y
Department of Otorhinolaryngology, Jichi Medical School, Minamikawachi, Japan.
Ann Otol Rhinol Laryngol. 1997 Apr;106(4):338-42. doi: 10.1177/000348949710600414.
A mitochondrial tRNALeu(UUR) mutation at nucleotide 3,243 is known to be found in most patients with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes) and has also been identified in several families with maternally inherited diabetes mellitus and hearing loss. We report here audiologic features in patients with hearing loss associated with the mutation. Four patients without and five with MELAS were studied. Most of the patients had bilateral progressive sensorineural hearing loss. The most common shape of the audiogram was sloping, while cases in the advanced stages had flat audiograms. Speech discrimination scores were generally poor and did not parallel the degree of hearing loss. The present study suggests that the lesion for hearing loss could include both cochlear and retrocochlear involvement, but does not demonstrate a significant difference in the audiologic findings between patients with and without MELAS.
已知在大多数线粒体脑肌病伴乳酸血症和卒中样发作（MELAS）患者中可发现核苷酸3243处的线粒体亮氨酸转运RNA（UUR）突变，并且在一些患有母系遗传性糖尿病和听力损失的家族中也已得到确认。我们在此报告与该突变相关的听力损失患者的听力学特征。对4例无MELAS的患者和5例有MELAS的患者进行了研究。大多数患者患有双侧进行性感音神经性听力损失。听力图最常见的形态为斜坡型，而晚期病例的听力图为平坦型。言语辨别得分通常较差，且与听力损失程度不平行。本研究表明，听力损失的病变可能包括耳蜗和蜗后受累，但未显示有MELAS患者和无MELAS患者在听力学检查结果上存在显著差异。
