关键词: 甲基丙二酸血症, 甲基丙二酸尿症, 甲基丙二酰辅酶A变位酶, 钴胺素, 诊断, 治疗

Abstract: Methylmalonic acidemia or aciduria （MMA） is a common organic acidemia/aciduria in China. It is caused by the metabolic disorder of methylmalonyl-CoA mutase （MCM） or its coenzyme cobalamin （cbl）， resulting in a large number of metabolites accumulating in the body， and causing damage to nerves， liver， kidney， bone marrow and other organs. Due to the diverse clinical features and lack of specificity， it is particularly prone to misdiagnosis and missed diagnosis，and finally it has to be diagnosed by biochemical and metabolic examination and genetic testing. Once diagnosed， the patients with isolated MMA with no response or partial response to vitamin B12 should start limiting protein intake as early as possible. For patients with response to vitamin B12，long-term treatment with vitamin B12 can be given （hydroxycobalamin preferred）. MMA patients with hyperhomocysteinemia can be given oral betaine to reduce homocysteine levels. For MMA patients with secondary hyperammonemia， treatment with carglumic acid is of good efficacy. For patients with poor response to treatment， liver （or liver and kidney） transplantation may be attempted. Gene therapy has made some progress in animal experiments in recent years， and it is expected that it can be applied to patients in the future to achieve new breakthroughs.

Key words: methylmalonic acidemia, methylmalonic aciduria, methylmalonyl-CoA mutase, cobalamin, diagnosis, treatment