3-Methylglutaconic Aciduria Type 9
Autosomal recessive
Caused by changes in both copies of TIMM50, which encodes part of the machinery that imports proteins into the mitochondria, the cell's energy-producing structures. Reduced TIMM50 function impairs mitochondrial energy production.
Signs and symptoms
Often begins early in life with seizures, which can be difficult to control, alongside developmental delay and intellectual disability. Urine tests show raised 3-methylglutaconic acid, and blood lactate may be slightly raised. Heart muscle disease (cardiomyopathy) has also been reported.
What a diagnosis changes
Care is supportive, with seizure treatment, developmental support and monitoring for heart involvement. Because it is recessive, parents are usually carriers, so each pregnancy carries a recurrence risk; genetic counselling and carrier testing of relatives are available.
Genes analysed
Also known as
3-methylglutaconic aciduria-epilepsy-spasticity-severe intellectual disability syndrome; MGA9; MGCA9
