一个可能为X染色体显性遗传的单一镫骨畸形家系的临床研究

Clinical study of a single congenital stapes malformation with possible X-linked dominant inheritance

目的研究一个可能为X染色体显性遗传的先天性单一镫骨畸形家系的发病机制、相关基因、听力学特点及遗传特征。方法对所有家系成员都询问病史,进行体格、纯音测听、声阻抗等检查,部分患者还接受了高分辨率颞骨CT检查和免疫学检查;对先证者进行染色体核型分析,并实施了左耳的人工镫骨安装手术。结果经检查可以排除综合征性耳聋。该家系连续3代以上发病,女性发病机会较男性大。患病的母亲可将致病基因传给下一代,患病的父亲则未能传给儿子。听力检查显示,他们的耳聋呈传导性,骨、气导差都≤40dB,声阻抗检查均为A型曲线,颞骨高分辨CT可显示正常的内耳结构。在先证者的手术中发现其镫骨呈扁圆柱型且缺少足板,染色体核型分析显示核型为46,XX。结论该家系中的患者们有着单一的先天性镫骨畸形伴固定的特征,家系分析显示为可能X染色体显性遗传。

Objectives：To study the etiology of one Chinese pedigree with familial conductive deafness which was demonstrated involvment of X-linked dominant inheritance. Method.. History of illness, physical examinations, pure-tone audiometry and acoustic and immittance measurement were obtained from members of this family. Some subjects received computed tomography scan of the temporal bone. The proband accepted chromatosome caryotype analysis and operation with artificial stapes prosthesis. Result： The patients had normal physical examinations. Pedigree analysis indicated that they distributed four continuous generations and the number of female patients was larger than that of male patients. Only female patients can transmit the mutant gene to their later generations. Their audiological evaluation showed conductive hearing loss and acoustic immittance measurement showed A form curve. Two of them who underwent high-resolution CT scan had normal innear structures. In the operation for proband, we found that her stapes which was flat cylinder shape lacking stape footplate. Furothermore, her chromatosome showed 46,XX. Conclusion： Patients with characteristics of congenital non-syndrome stapes fixation were identified in one large Chinese family. Pedigree analysis suggested a possible X linked dominant inheritance in this pedigree.