An autosomal recessive inherited disorder caused by mutations in the BCKDHA, BCKDHB, DBT, and DLD genes. It is characterized by a deficiency of branched-chain alpha-keto acid dehydrogenase complex, leading to accumulation of metabolites in the body fluids. The name of the disease derives from the sweet odor of the urine in infants, reminiscent of maple syrup. Signs and symptoms usually appear in infancy and include lethargy and developmental delays. If untreated, it may lead to seizures, coma, and death. The disease is MONDO_0009563 (maple syrup urine disease). Also known as: BCKD deficiency, BCKDH deficiency, Ketoacidaemia, MSUD, branched chain ketoaciduria, branched-chain 2-ketoacid dehydrogenase deficiency, branched-chain ketoaciduria.