3-Methylglutaconic aciduria type 1 (MGCA1)


Autosomal recessive

Inheritance from both parents will result in the disease

Age range at onset:

Neonatal or infancy (rarely adulthood)

Specialists you may see:


While symptoms may begin in the neonatal period, diagnosis of MGCA1 often happens later in childhood, following symptoms such as hypoglycaemia, microcephaly, spastic quadriparesis, seizures, vomiting, hypotonia, hepatomegaly, dystonia and progressive neurological deficit. Optic atrophy may occur, and severely affected individuals may become comatose.

Those who begin to experience MGCA1 in adulthood have symptoms such as dysarthria, ataxia, spasticity, optic atrophy and dementia.


Caused by mutations in the AUH gene. This gene creates 3- methylglutaconyl-CoA hydratase – an enzyme. This enzyme breaks down an amino acid to create energy. When the AUH gene is mutated, the amino  acid is not broken down, creating an accumulation in the fluids surrounding the brain and spinal cord. Researchers think that this causes damage, leading to the symptoms described.