What Your Test Results Mean:

Carriers typically show no symptoms of glutaric acidemia type I; however, carriers are at an increased risk of having a child with glutaric acidemia type 1. Risk for the current or future pregnancies is dependent on your partner’s carrier status. Carrier testing of your partner is recommended in addition to consultation with a genetic counselor for more detailed risk assessment.

Disease Explained:

Glutaric acidemia type I is an inherited metabolic disorder caused by a missing enzyme, glutaryl-CoA dehydrogenase. Without this enzyme, the body cannot break down the amino acids lysine and tryptophan. Symptoms may include metabolic crisis (severe vomiting and lethargy that can lead to seizures and other complications) in times of illness, fever, or fasting. To avoid a metabolic crisis, individuals with the disorder should avoid fasting and may be placed on a special diet. Diet and medications for individuals with glutaric academia type I are typically managed by a metabolic physician and dietician. With proper management, most individuals with glutaric academia type I will live long and healthy lives.

How the Genetics Works:

Glutaric acidemia type I is an autosomal recessive disorder caused pathogenic variants in the GCDH gene. In general, individuals have two copies of the GCDH gene. Carriers of glutaric acidemia type I have a single variant in one copy of the GCDH gene while individuals with glutaric acidemia type I have variants in both copies of their genes, one inherited from each parent. Risk for two carriers to have a child with the disorder is 25%.