Long-Chain 3-Hydroxyacyl-CoA Dehydrogenase Deficiency (HADHA)

Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHAD) is a pan-ethnic autosomal recessive condition caused by pathogenic variants in the gene HADHA. It prevents the body from properly turning fats into energy. The clinical presentation is highly variable. Symptoms most commonly begin in infancy or early childhood with low blood sugar, lethargy, low muscle tone, liver disease, and heart problems. Treatment with a special low-fat diet improves but does not eliminate symptoms. Long-term problems include peripheral neuropathy (nerve pain) and retinal disease which in some people progresses to blindness. LCHAD is highly variable in its severity, and some people are so mildly affected that they do not know that they have LCHAD until a family member is diagnosed. Life expectancy depends on the severity of symptoms, but ranges from infancy to adulthood. It is not currently possible to predict how severe the disease will be based on the type of variants inherited.

For information about carrier frequency and residual risk, please see the residual risk table.