Very long-chain acyl-coenzyme A dehydrogenase deficiency

Very long-chain acyl-coenzyme A dehydrogenase deficiency is a condition that prevents the body from converting certain fats to energy, particularly during periods without food (fasting). Normally, through a process called fatty acid oxidation, several enzymes work in a step-wise fashion to break down (metabolize) fats and convert them to energy. People with very long-chain acyl-coenzyme A dehydrogenase deficiency have inadequate levels of an enzyme that metabolizes a group of fats called very long-chain fatty acids.

Typically, initial signs and symptoms of this disorder occur during infancy or childhood and include low blood sugar (hypoglycemia), lack of energy (lethargy), and muscle weakness. People with an early onset of very long-chain acyl-coenzyme A dehydrogenase deficiency are also at risk of serious complications such as liver abnormalities and life-threatening heart problems. Symptoms that begin in adolescence or adulthood tend to be milder and usually do not involve heart problems. Episodes of very long-chain acyl-coenzyme A dehydrogenase deficiency can be triggered by periods of fasting, illness, and exercise.

Very long-chain acyl-coenzyme A dehydrogenase deficiency is estimated to affect 1 in 40,000 to 120,000 people.

Mutations in the ACADVL gene cause very long-chain acyl-coenzyme A dehydrogenase deficiency.

Mutations in the ACADVL gene lead to inadequate levels of an enzyme called very long-chain acyl-coenzyme A dehydrogenase. Without sufficient amounts of this enzyme, very long-chain fatty acids from food and fats stored in the body are not metabolized properly. As a result, these fats are not converted to energy, which can lead to characteristic signs and symptoms of this disorder such as lethargy and low blood sugar. Very long-chain fatty acids or partially metabolized fatty acids may accumulate in tissues and can damage the heart, liver, and muscles, causing serious complications.

Read more about the ACADVL gene.

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.