摘要目的:对1例二氢硫辛酰胺脱氢酶(dihydrolipoamide dehydrogenase，DLD)缺乏症患儿 DLD基因进行变异分析，明确其致病原因。 方法:应用全外显子测序及Sanger测序法对患儿 DLD基因进行变异检测。 结果:测序结果显示患儿 DLD基因存在c.704_705delTT(p.Leu235Argfs*8)和c.1058T>C(p.Ile353Thr)复合杂合变异，其表型正常的父母分别携带c.704_705delTT(p.Leu235Argfs*8)杂合变异和c.1058T>C(p.Ile353Thr)杂合变异，患儿弟弟未携带上述2个变异。其中c.1058T>C(p.Ile353Thr)变异为已报道的致病变异；c.704_705delTT(p.Leu235Argfs*8)变异为未报道过的新变异，参照美国医学遗传学与基因组学学会评级指南提示其为致病性变异(PVS1＋PM2＋PP4)。 结论:DLD基因c.704-705delTT和c.1058T>C变异为该患儿的致病原因，基因检测结果可为临床诊断、家系遗传咨询和产前诊断提供依据。

abstractsObjective:To analyze the clinical and genetic characteristics of a patient with dihydrolipoamide dehydrogenase deficiency.Methods:Potential variants of the DLD gene were detected by whole exome sequencing and verified by Sanger sequencing. Results:Compound heterozygous variants, c. 704_705delTT (p.Leu235Argfs*8) and c. 1058T>C (p.Ile353Thr), were detected in the DLD gene. The c. 1058T>C (p.Ile353Thr) variant was derived from his mother and known to be pathogenic. The c. 704_705delTT (p.Leu235Argfs*8) variant was derived from his father and was unreported previously. Conclusion:The compound heterozygous variants of c. 704_705delTT (p.Leu235Argfs*8) and c. 1058T>C (p.Ile353Thr) of the DLD gene probably underlay the disease in this patient. Above finding has facilitated genetic counseling and prenatal diagnosis for the family.