摘要目的 鉴定1例皮肤、虹膜色素沉着异常、先天性听力缺失合并多发先天异常患儿的遗传学病因.方法 应用常规G显带技术分析患儿及其父母外周血染色体,之后应用单核苷酸多态性芯片(single nucleotide polymorphism array,SNP array)检测患儿的微小染色体改变.用荧光定量PCR验证芯片的检测结果.结果 常规染色体核型分析显示患儿及其父母的染色体均为正常核型,其中患儿核型为46,XY.SNP array分析发现患儿3号染色体短臂结构异常,结果 显示在3p13p14.1区存在3.9 Mb的缺失(位于此区域的MITF基因全部缺失).荧光定量PCR结果与芯片结果一致.患儿临床表现为先天性耳聋(双侧听力严重损失),皮肤和虹膜色素沉积减少及多发畸形.结论 本例患者的异常表型是由3p13p14.1区存在缺失而导致的,并表现为Tietz综合征(或)Waardenburg综合征,为临床表型和基因型的关联研究提供了新的资料.

abstractsObjective To determine the genetic cause for a patient featuring decreased pigmentation of the skin and iris,hearing loss and multiple congenital anomalies.Methods Routine chromosomal banding was performed to analyze the karyotype of the patient and his parents.Single nucleotide polymorphism array (SNP array) was employed to identify cryptic chromosome aberrations,and quantitative real-time PCR was used to confirm the results.Results Karyotype analysis has revealed no obvious anomaly for the patient and his parents.SNP array analysis of the patient has demonstrated a 3.9 Mb deletion encompassing 3p13p14.1,which caused loss of entire MITF gene.The deletion was confirmed by quantitative real-time PCR.Clinical features of the patient have included severe bilateral hearing loss,decreased pigmentation of the skin and iris and multiple congenital anomalies.Conclusion The patient,carrying a 3p13p14.1 deletion,has features of Tietz syndrome/ Waardenburg syndrome type Ⅱ a.This case may provide additional data for the study of genotype-phenotype correlation of this disease.