Dudipala Sai Chandar, M Prashanthi, B Krishna Chaithanya, Chenalla Laxman Kumar
Pediatric Neurology, Star Women and Children Hospital, Karimnagar, IND.
Pediatrics, Prathima Institute of Medical Sciences, Karimnagar, IND.
Cureus. 2020 Dec 7;12(12):e11951. doi: 10.7759/cureus.11951.
3-Methylglutaconic aciduria type I (3-MGA I) is a rare inherited disorder of the leucine metabolism pathway due to mutations in the AUH gene for 3-methylglutaconyl-CoA hydratase enzyme and enzyme deficiency. It has a variable phenotypic presentation from infancy to adulthood. Here, we report a three-year-old female patient with normal development presented with acute encephalopathy and status dystonicus. Neuroimaging was normal. Urine organic acid analysis showed high levels of 3-methylglutaconic acid, 3-hydroxyisovaleric acid. Next-generation sequencing revealed a novel homozygous mutation of variant c.505+1G>C (5' splice site) in intron 4 of the AUH gene that was compatible with the diagnosis of 3-MGA I. The child was asymptomatic on follow-up with a low leucine diet. Clinicians should suspect rare inherited metabolic disorders in acute onset unexplainable neurological symptoms and evaluate with urine organic acid analysis.
I型3-甲基戊二酸尿症（3-MGA I）是一种罕见的亮氨酸代谢途径遗传性疾病，由3-甲基戊二酰辅酶A水合酶的AUH基因突变和酶缺乏引起。其表型从婴儿期到成年期各不相同。在此，我们报告一名发育正常的三岁女性患者，出现急性脑病和张力障碍状态。神经影像学检查正常。尿有机酸分析显示3-甲基戊二酸、3-羟基异戊酸水平升高。下一代测序揭示了AUH基因第4内含子中一个新的纯合变异c.505+1G>C（5'剪接位点），与3-MGA I的诊断相符。该患儿采用低亮氨酸饮食随访时无症状。临床医生在遇到急性发作且无法解释的神经症状时，应怀疑罕见的遗传性代谢疾病，并通过尿有机酸分析进行评估。
