(MGA) 3-Methylglutaconic acidemia or 3-Methylglutaconyl-CoA Hydratase Deficiency
3-Methylglutaconic aciduria type I (250950) is an autosomal recessive disorder characterized clinically by various symptoms ranging from mild features, including delayed speech development and hyperchloremic acidosis associated with gastroesophageal reflux, to a more severe phenotype, including seizures and cerebellar abnormalities. The disorder is caused by deficiency of 3-methylglutaconyl-CoA hydratase, one of the key enzymes of leucine degradation. The enzyme deficiency results in elevated urinary levels of 3-methylglutaconic acid, 3-methylglutaric acid, and 3-hydroxyisovaleric acid. Fewer than 50 cases of this disorder have been identified.