目的　确定戊二酸血症I型家系的致病基因，以提供遗传咨询和产前诊断。方法　应用Ion Torrent半导体测 序技术检测1例戊二酸血症I型患儿戊二酰辅酶A脱氢酶（GCDH）基因，筛选致病变异，并对患儿双亲以Sanger测序验证。 患儿母亲再孕18周时行羊膜腔穿刺术取羊水胎儿细胞检测GCDH基因。结果　男性患儿， 4岁，GCDH基因（NM_000159） 存在致病变异c.395G>A（p.R132Q）杂合突变，来自父亲；c.769C>T（p.R257W）杂合突变，来自母亲。患儿母亲羊水标 本基因检测显示胎儿GCDH基因c.395位点和c.769均未发生变异，新生儿血串联质谱检测及生长发育情况均无异常。结 论　成功确定一个戊二酸血症I型家系的GCDH基因致病突变位点，并为患儿母亲提供了产前分子遗传学诊断。

Objective　To identify pathogenic gene mutations of glutaric aciduria typeⅠand provide genetic counseling and prenatal diagnosis for a Chinese family. Methods　Mutation of glutaryl-CoA dehydrogenase (GCDH) gene was detected in the proband with glutaric aciduria typeⅠby Ion Torrent semi-conductor sequencing for the screening of the pathogenic mutations. Both parents were verified by Sanger sequencing. Amniotic fluid fetal cells were extracted by amniocentesis at 18 weeks of gestation to detect GCDH gene. Results　The 4-year-old boy had pathogenic variations in the GCDH gene (NM_000159), including heterozygous mutations from the father c.395G>A (p.R132Q) and from the mother c.769C>T (p.R257W). The gene detection of amniotic fluid samples of the mother showed no mutation in c.395 and c.769 of GCDH gene, and there was no abnormality in the results of blood tandem mass spectrometry and growth in the neonate. Conclusions　The pathogenic mutation site of GCDH gene in a family of glutaric aciduria typeⅠwas successfully identified and prenatal molecular genetic diagnosis was provided to the mother of the child.