An amino acid metabolic disorder characterized by metabolic acidosis without ketonuria, hypoglycemia, and a characteristic pattern of elevated urinary organic acid metabolites, including 3-hydroxy-3-methylglutaric, 3-methylglutaric, and 3-hydroxyisovaleric acids that has_material_basis_in homozygous or compound heterozygous mutation in the HMGCL gene on chromosome 1p36.11.