CYP17基因新的突变导致两姐妹17α羟化酶/17,20裂链酶联合缺乏

Combined deficiency of steroid 17-α-hydroxylase/17 and 20-lyase induced by mutation of homozygous 985del TAC insAA of CYP17 gene

目的分析一家庭中患17α羟化酶/17,20裂链酶联合缺乏症的两姐妹及其父母的CYP17基因序列。方法外周血中提取基因组DNA。设计引物行PCR反应并对PCR产物进行序列测定。结果两姐妹均表现为典型的17α羟化酶/17,20裂链酶联合缺乏,其CYP17基因均为985缺失TAC插入AA的纯合子突变,而其父母是杂合子突变。结论985缺失TAC插入AA杂合子仅是一遗传标志,并不能引起疾病,但这种纯合子突变或在此基础上再发生另一突变可导致疾病的发生。

Objective To analyze the CYP17 gene of two sisters with combined 17-alpha hydroxylase/17, 20-1yase deficiency, and that of their parents. Methods Genomic DNA of the four members was prepared from peripheral blood by standard methods. All the eight exons and intron/exon boundaries of CYP17 were PCR amplified and sequenced. All the hormone levels were measured by time-resolved immunofluorometric assay. Results Combined 17-α-hydroxylase/17, 2（〉lyase deficiency was confirmed by marked hormone change. Sequence analysis revealed that the sisters were homozygous 985delTAGnsAA of CYP17, and their parents were heterozygous 985delTACinsAA. Conclusion Novel mutation of 985delTACinsAA in CYP17 was found in two sisters with 17-α-hydroxylase/17, 2（〉lyase deficiency. The homozygous one can induced the phenotype and the heterozygous one is a genomic marker.