摘要目的:对一例全面发育落后的婴儿进行临床和遗传学分析，明确其病因。方法:采集患儿及其家系成员的病史，应用实验室检查、遗传代谢病筛查和新一代测序技术对该家系进行临床和遗传学分析。结果:先证者临床表现为对声音反应不灵敏，竖头不稳，不能翻身、逗笑，不认识母亲。实验室检查血乳酸、血糖等正常，尿有机酸中3-甲基戊烯二酸、3-甲基戊二酸水平增高，提示为"3-甲基戊烯二酸尿症可能"。头颅磁共振扫描显示胼胝体压部T1W信号偏低，髓鞘化落后于月龄。高通量测序发现 CLPB基因存在复合杂合变异c.1085G>A和c.1700A>C，分别遗传自父亲和母亲，二者均为新变异。根据美国医学遗传学与基因组学学会标准，两个变异均预测为疑似致病变异。 结论:该患儿可能为 CLPB基因变异引起的3-甲基戊烯二酸尿症Ⅶ型。高通量测序技术为分析该类疾病提供了有力的诊断工具。

abstractsObjective:To analyze the clinical and genetic characteristics of an infant girl featuring comprehensive developmental backwardness.Methods:The patient was subjected to clinical examination, gas chromatography mass spectrometry and next-generation sequencing (NGS).Results:The child was insensitive to sound, could not turn over, raise head, laugh, or recognize his mother. Laboratory tests were all normal, but metabolic analysis suggested 3-methylglutaconic aciduria due to elevated 3-methylglutaconic acid and 3-methylglutaric acid. NGS has detected two compound heterozygous CLPB variants in the child, namely c. 1085G>A and c. 1700A>C, which were respectively inherited from her father and mother. Bioinformatic analysis predicted both variants to be pathogenic. The patient was diagnosed with 3-methylglutaconic aciduria type Ⅶ (MGCA7). Conclusion:The MGCA7 in the child was probably caused by CLPB gene variants. NGS has provided a powerful diagnostic tool for this rare disorder.