Morales Angulo Carmelo, Gallo-Terán Jaime, Señaris Blanca, Fontalva Ana, González-Aguado Rocío, Fernández-Luna José Luis
Servicio de ORL, Hospital Universitario Marqués de Valdecilla, Profesor Asociado Universidad de Cantabria, Santander, Spain.
Acta Otorrinolaringol Esp. 2011 Mar-Apr;62(2):83-6. doi: 10.1016/j.otorri.2010.08.003. Epub 2010 Dec 3.
The A1555G mitochondrial DNA (mtDNA) mutation is responsible for maternally inherited non-syndromic hearing loss that is increased by aminoglycoside exposure. The objective of this study was to ascertain the frequency of the A1555G mutation among patients without family history of hearing loss or known exposition to aminoglycosides.
We screened for the mtDNA A1555G mutation in Spanish patients with sporadic sensorineural hearing impairment without a known family history of hearing loss or aminoglycoside exposition seen at the ENT Department in Sierrallana Hospital (Torrelavega, Cantabria, Spain) over a four-year period.
A total of 219 patients with bilateral hearing loss were screened. Two of them (0.9%) had the A1555G mitochondrial DNA mutation. Both patients had a moderate bilateral sensorineural hearing loss for low frequency, and moderate to severe loss for high-frequency.
The mtDNA A1555G mutation in patients with sensorineural hearing loss without family history of deafness or aminoglycoside ototoxicity is infrequent in our region. We should suspect this mutation in patients younger than 50 years old, with postlingual bilateral sensorineural hearing loss that is more pronounced at high frequency.
A1555G线粒体DNA（mtDNA）突变可导致母系遗传的非综合征性听力损失，氨基糖苷类药物暴露会加重这种听力损失。本研究的目的是确定在无听力损失家族史或无已知氨基糖苷类药物暴露史的患者中A1555G突变的频率。
我们对西班牙西雷亚纳医院（西班牙坎塔布里亚自治区托雷拉韦加）耳鼻喉科在四年期间接诊的散发性感音神经性听力障碍患者进行了mtDNA A1555G突变筛查，这些患者无已知的听力损失家族史或氨基糖苷类药物暴露史。
共筛查了219例双侧听力损失患者。其中2例（0.9%）存在A1555G线粒体DNA突变。两名患者均为低频中度双侧感音神经性听力损失，高频为中度至重度损失。
在我们地区，无耳聋家族史或氨基糖苷类药物耳毒性的感音神经性听力损失患者中，mtDNA A1555G突变并不常见。对于50岁以下、伴有高频更明显的语言后双侧感音神经性听力损失的患者，我们应怀疑存在这种突变。
