Short-chain 3-hydroxyacyl-CoA dehydrogenase deficiency associated with hyperinsulinism: a novel glucose–fatty acid cycle?

Hyperinsulinism of infancy is caused by inappropriate insulin secretion in pancreatic β-cells, even when blood glucose is low. Several molecular defects are known to cause hyperinsulinism of infancy, such as K_ATP channelopathies and regulatory defects of glucokinase and glutamate dehydrogenase. Although defects of fatty acid oxidation have not previously been known to cause hyperinsulinism, patients with deficiency in SCHAD (short-chain 3-hydroxyacyl-CoA dehydrogenase; an enzyme of mitochondrial β-oxidation) have hyperinsulinism. A novel link between fatty acid oxidation and insulin secretion may explain hyperinsulinism in these patients.