Hyperammonaemia

Gene: AUH

Green List (high evidence)

3-Methylglutaconic aciduria type I (MGCA1) is a rare autosomal recessive disorder of leucine catabolism. The metabolic landmark is urinary excretion of 3-methylglutaconic acid (3-MGA) and its derivatives 3-methylglutaric acid (3-MG) and 3-hydroxyisovaleric acid (3-HIVA). Two main presentations have been described: one with onset in childhood associated with the nonspecific finding of psychomotor retardation, and the other with onset in adulthood of a progressive neurodegenerative disorder characterized by ataxia, spasticity, and sometimes dementia; these patients develop white matter lesions in the brain. However, some asymptomatic paediatric patients have been identified by newborn screening and show no developmental abnormalities when reexamined later in childhood.

More than 5 unrelated families reported.

Created: 29 Dec 2021, 9:16 p.m. | Last Modified: 29 Dec 2021, 9:16 p.m.

Panel Version: 0.10389

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
3-methylglutaconic aciduria, type I, MIM# 250950

Publications

• 12434311
• 16354225
• 20855850
• 21840233