Mitochondrial Short-Chain Enoyl-CoA Hydratase 1 Deficiency
Autosomal recessive
Caused by changes in both copies of ECHS1, which encodes a mitochondrial enzyme in fatty acid metabolism. Its deficiency can cause severe lactic acidosis, a sign of impaired mitochondrial energy production.
Signs and symptoms
More commonly it begins in infancy with developmental delay or regression, dystonia, low muscle tone and basal ganglia changes on brain MRI, which are very common. Some infants have a severe neonatal form with heart muscle disease and severe lactic acidosis. In a later-onset form, the course is milder, with episodes of dystonia triggered by exercise or illness.
What a diagnosis changes
Care is led by metabolic specialists; a valine-restricted diet has been used in some people with reported benefit. Avoiding prolonged fasting and prompt treatment during illness are important, along with supportive therapies. Both parents of an affected child are usually carriers, so each further child has a 1 in 4 chance of being affected; genetic counselling and carrier testing of relatives are available.
Genes analysed
Also known as
ECHS1D; short-chain enoyl-CoA hydratase deficiency
