摘要目的 探讨1例经串联质谱新生儿筛查发现并确诊的戊二酸血症Ⅰ型双胞胎的临床表现和基因变异特点.方法 收集患儿的临床资料,采用定制的常见遗传代谢病基因包进行捕获测序和致病变异分析,用Sanger法对双胞胎及其父母进行测序验证.结果 男胎血片戊二酰基肉碱(C5DC+C6OH)初筛值为3.26 μmol/L,尿气相色谱质谱分析戊二酸547.51,颅脑B超检查示“室管膜下出血可能”,尚未出现严重的临床表现,诊断为予特殊奶粉喂养、加用左卡尼汀口服后生长发育情况良好.患儿GCDH基因存在两处杂合变异:c.109_110delCA和c.416C＞G,其中c.416C＞G为疑似致病变异,c.109_110delCA为未经报道的变异,分别来源于其父母.女胎存在一个c.416C＞G位点杂合变异.结论 血串联质谱、尿气相色谱质谱分析结合影像学、基因检测可明确诊断戊二酸血症Ⅰ型,对于早期诊断和治疗本病具有重要的价值.

abstractsObjective To review the clinical features of the twin affected with glutaric academia type Ⅰ (GA-Ⅰ) and to analyse the variations of glutaryl-CoA dehydrogenase.Methods Clinical data of the twins and their parents were collected.Genomic DNA was extracted from blood samples and Variants analysis of GCDH genes was carried out by capture sequencing with customized panel.Then the variants of the twins and parents finally verified by Sanger sequencing.Results The level of glutaric acyl carnitine (C5DC + C6OH) was 3.26 μmol/L in male fetus.The relative level of glutaric acid in urine was 547.51 by gas chromatography mass spectrometry analysis.The subependymal hemorrhage existed by cerebral ultrasound,and he had no serious clinical manifestation.After treatment of special formula milk powder and L-carnitine,the growth and development of boy was in good shape.There were two heterozygous variants in the GCDH gene in boy affected by GA-Ⅰ.c.416 C ＞G was suspected to be pathogenic variant,and c.109 110delCA was not reported.These two variants were from his parents.The girl of twins had one c.416C＞G heterozygous variant.Conclusion GA-Ⅰ can be diagnosed by mass spectrometry,urine gas chromatographic mass spectrometry,imaging examination and genetic diagnosis.It is important for early intervention and early diagnosis.