Malonyl-CoA decarboxylase deficiency is a rare autosomal recessive disease characterized by developmental delay, seizure, hypoglycemia, cardiomyopathy and malonic aciduria. Malonyl-CoA decarboxylase (MCD) is an enzyme involved in the metabolism of fatty acids synthesis and is important in muscle and brain metabolism. Mutations in MLYCD gene that encodes MCD, result in a deficiency of MCD activity.