HMGCL gene encodes a mitochondrial enzyme named 3-hydroxymethyl-3-methylglutaryl-CoA lyase (HMG-CoA lyase). This enzyme belongs to the HMG-CoA lyase family. It catalyzes the final step of leucine degradation and plays a critical role in ketone body formation.
Mutations in HMGCL gene cause 3-hydroxymethyl-3-methylglutaryl-CoA lyase deficiency - an autosomal recessive disease characterized by vomiting, seizures, metabolic acidosis, hypoketotic hypoglycemia, and lethargy.