What Your Test Results Mean:

Carriers typically show no symptoms of VLCAD deficiency; however, carriers are at an increased risk of having a child with VLCAD deficiency. 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.

Disease Explained:

VLCAD deficiency is an inherited disorder that prevents the body from converting certain fats to energy, particularly during fasting periods. Pathogenic variants in the ACADVL gene result in a build up of very long-chain fatty acids. Symptoms of VLCAD deficiency usually appear during infancy or early childhood and can include low blood sugar, lack of energy, and muscle weakness. Serious complications include liver abnormalities and life-threatening heart problems. The later the symptoms first develop, the milder the disorder. Affected individuals exhibit the most problems during periods of fasting, illness, and exercise. VLCAD deficiency is usually not fatal as long as it is diagnosed early. Treatment is usually required throughout life for those affected with VLCAD deficiency. Affected individuals should avoid going a long time without food in order to prevent a metabolic crisis. Management is overseen by a group of metabolic specialists.

How the Genetics Works:

VLCAD deficiency is an autosomal recessive metabolic disorder caused by pathogenic variants in the ACADVL gene. All individuals have two copies of the ACADVL gene. Carriers of VLCAD deficiency have a variant in one copy of the ACADVL gene while individuals with VLCAD deficiency have variants in both copies of ACADVL, one inherited from each parent. Risk for two carriers to have a child with the disorder is 25%.