Organic Acidaemias
Glutaric Acidaemia Type 1 (GA1)
Definition
Glutaric Acidaemia type 1 is an autosomal recessive hereditary disorder caused by a deficiency of the enzyme glutaryl-CoA dehydrogenase. People with this disorder have inadequate levels of an enzyme that helps break down the amino acids lysine, hydroxylysine, and tryptophan, which are building blocks of protein. Accumulation of 5- carbon dicarboxylic acids may impair synthesis of gamma-aminobutyric acid (GABA), which functions as a neurotransmitter in the brain, inhibiting nerve excitation. The severity of glutaric acidemia type I varies widely; some individuals are only mildly affected, while others have severe problems.
Diagnosis
The condition is diagnosed during newborn screening via the heel prick test taken 48-72 hours after birth.
Prevalence
1:30,000 – 40,000 estimated worldwide.
Treatment
The treatment of Glutaric Acidaemia type 1 consists of a low protein diet aimed at reducing the production of glutaric acid and other intermediate metabolites. The diet involves restricting the intake of natural protein and of lysine specifically and a supplement with lysine-free, low-tryptophan amino acid mixtures to ensure supply of the other amino acids essential for optimal health. The diet should include a high carbohydrate and fat content to provide sufficient calories. Adequate fluid levels should be maintained and vitamin and mineral intake optimised. During illness treatment will be different and you will need to ring your metabolic doctor/dietitian or the 24hour emergency number you have been given.
Support Links & Materials
Urea Cycle Disorders (UCD)
Ornithine Transcarbamylase Deficiency (OTC)
Citrullinaemia
Argininosuccinic Acidaemia (ASA)
Arginase Deficiency (ARG)