目的:分析2个大前庭水管家系中患者的临床表现及基因型。方法:应用PDS(SLC26A4)基因检测方法进行2个家系成员的基因型分析。所有患者和父母均采集外周血,以试剂盒方法提取DNA。先行Exon7+8序列分析,未见突变后再扩增其余17个片段,以覆盖PDS基因全部cDNA序列及每个外显子前后的剪切区序列,以变性高效液相色谱仪分析每个扩增子,如待测标本与对照组标本的混合物的过柱波形与对照组相比有前移、后移或有明显的波形畸变,特别是出现2~4个波峰,则判定为待测标本的扩增片段内可能存在序列变异,将此待测标本的扩增子进行全自动序列分析。结果:2个家系的共同特点为父母非近亲结婚,听力均正常,父母双方家族内无其他成员发生耳聋;但2个家系均有2个子女患病,患者临床特征为听力进行性下降,交流良好,但发声略含糊。家系1孪生姐妹在2年内3次纯音测听呈现听阈进行性增高;Exon7+8序列分析结果显示孪生姐妹均具有IVS7-2A-G纯合突变,其父母均携带IVS7-2A-G杂合突变。家系2先证者发现DHPLC异常波形2个,分别分布在外显子2和外显子10,序列分析发现先证者的外显子10存在T410M和1199ins T复合突变,其兄具有同样的复合突变。结论:家族性大前庭水管综合征是典型的遗传性疾病,单个家族内患病个体具有相似的临床表现和相同的变异基因型。 Objective: To analyze the clinical manifestations and genotypes of two large vestibular aqueduct families. Methods: Genotype analysis of two pedigree members was performed using the PDS (SLC26A4) gene test. Peripheral blood was collected by all patients and parents, and DNA was extracted by kit method. Exon7 + 8 sequence analysis was performed first, and then the remaining 17 fragments were amplified without mutation to cover the entire cDNA sequence of PDS gene and the sequence of the cleavage region before and after each exon. Each amplification was analyzed by denaturing high performance liquid chromatography Additives, such as samples of test specimens and control samples of the column waveform compared with the control group had forward, after the shift or obvious waveform distortion, especially the emergence of 2 to 4 peaks, then determine the test specimen Of the amplified fragments may exist sequence variation, the amplicons of the specimen to be tested for automatic sequence analysis. Results: The common features of the two families were that their parents were married without any close relatives, their hearing was normal, and no other members of both parents had deafness. However, the two families had two children and the clinical features of the patients were decreased hearing and communication Good, but vaguely vocal. The twin sisters of family 1 had three thresholds of pure tone audiometry within 2 years. The results of Exon 7 + 8 analysis showed that all twin siblings had IVS7-2A-G homozygous mutation, and both parents carried IVS7-2A-G heterozygous mutation . Family 2 proband found DHPLC abnormal waveform 2, respectively, located in exon 2 and exon 10, sequence analysis found proband exon 10 exists T410M and 1199ins T compound mutation, the brother has the same compound mutation . CONCLUSIONS: Familial vestibular aqueduct syndrome is a classic hereditary disease with similar clinical manifestations and the same variant genotype in affected individuals within a single family.