一个常染色体显性遗传低频感音神经性聋家系听力学及遗传学特征分析

Genetic and Audiological Characteristics of a Chinese Family with Autosamal Dominant Hereditary Non-syndromic Low-frequency Sensorineural Hearing Loss

目的分析一个常染色体显性遗传性聋家系的临床听力学特征及遗传规律。方法对一个常染色体显性遗传低频感音神经性聋家系28名成员进行病史采集、体检及纯音测听、声导抗检查并绘制系谱图。其中，5名患者进行耳声发射、听性脑干反应检查，2名患者进行前庭功能及颞骨CT扫描检查以排除听神经病及听觉系统的其他病变。全部成员均应用微卫星标记对DFNA21个位点23个基因进行初步筛查，数据分析采用连锁分析方法。结果该耳聋家系（命名为BJ—L046）遗传方式为常染色体显性遗传，耳聋患者表现为迟发型的、渐进性的、以低频下降为主的听力损失，发病年龄5～28岁，早期以低频损失为主，听力曲线呈上升型，随着年龄增长逐渐累及全频听力，听力曲线由上升型变为平坦型。全部家系成员FNA21个位点23个基因筛查均为阴性。结论该耳聋家系为常染色体显性遗传方式，表现为低频感音神经性聋，数据连锁分析无阳性发现，初步排除了21个DFNA位点23个已知基因。

Objective To investigate the phenotype and genetic characteristics of a Chinese family with an autosomal -- dominant inherited sensorineural hearing loss. Methods A Chinese pedigree associated with an autosomal dominant inherited low -- frequency sensorineural hearing loss （LFSNHL） was investigated. After obtaining in- formed consent from all study participants medical and audiological examination were used to rule out any syndromic hearing impairment. Five patients were tested with DPOAE and ABR, while two patients were tested with vestibu lar function and computed tomography scan of the temporal bone to exclude auditory neuropathy and other possible aural disorders. Twenty--one loci and twenty--three genes of DFNA screening had been done by using microsatellite markers and linkage analysis. Results Proband of the family had been diagnosed with low--frequency sensorineural hearing loss. A Chinese family BJ-L046 with non -- syndromic autosomal dominant hearing loss was ascer tained. Hearing impairment in the affected members in family BJ--L046 occured from 10 to 20 years of age and mainly affected the low frequencies, causing an upsloping audiogram. Higher frequencies were getting involved with increasing age , thus causing a flat - type audiogram. No positive result was found in twenty one loci and twenty -three genes of DFNA screening. Conclusion A Chinese family with late--onset low - frequency sensorineural hearing loss was clinically studied. No positive result was found by linkage analysis,and twenty--one loci and twen-ty--three genes of DFNA were preliminary excluded.