1例临床诊断为17-α羟化酶/17,20-裂解酶缺陷症患儿及其父母和哥哥的基因检测分析

Genetic analysis of a child with 17α-hydroxylase/17,20-lyase deficiency and her parents and elder brother

目的了解17-α羟化酶/17,20-裂解酶缺陷症(17α-hydroxylase/17,20-lyasedeficiency,17OHD)患儿的基因变异及遗传情况。方法1例主要临床表现为双侧腹股沟区肿物、外生殖器女性化的假两性畸形患儿,临床诊断为17OHD,抽取患儿、患儿父母及哥哥的外周静脉血,采用高通量测序技术(High-ThroughputSequencing,HTS)进行全基因组外显子测序,分析患儿、患儿父母及哥哥的基因情况。结果患儿细胞色素P450c17酶基因(Cytochrome P450c17 enzymegene,CYP17A1 gene)第6外显子存在c.987delC(p.Tyr329fs)纯合突变;患儿父母及其哥哥均存在10号染色体CYP17A1基因第6外显子c.987delC(p.Tyr329fs)杂合突变。结论17OHD患儿存在10号染色体CYP17A1基因第6外显子c.987delC(p.Tyr329fs)纯合突变,其父母、哥哥均存在10号染色体CYP17A1基因第6外显子c.987delC(p.Tyr329fs)杂合突变。17OHD患儿的外显子突变遗传自父母。

Objective To investigate the genetic variation and inheritance of a child with 17α-hydroxylase/17,20-lyase deficiency(17OHD).Methods A child was diagnosed with 17OHD,and the main clinical manifestations were bilateral inguinal mass and feminization of external genitalia pseudohermaphroditism.We extracted peripheral venous blood from the child,her parents and her elder brother.Whole-genome exon sequencing was performed by using High-Throughput Sequencing(HTS)technology to analyze the gene of the patient,her parents and her elder brother.Results A homozygous mutation c.987delC(p.Tyr329fs)located in exon 6 of cytochrome P450c17 enzyme gene(CYP17A1 gene)was identified in the child.A heterozygous mutation c.987delC(p.Tyr329fs)located in exon 6 of CYP17A1 gene on chromosome 10 was identified in both her parents and her elder brother.Conclusions The child with 17OHD had a homozygous mutation c.987delC(p.Tyr329fs)located in exon 6 of CYP17A1 gene on chromosome 10.Her parents and her elder brother had heterozygous mutation c.987delC(p.Tyr329fs)located in exon 6 of CYP17A1 gene on chromosome 10.The exon mutation in patient with 17OHD was inherited from parents.