Beta-ketothiolase (T2) deficiency is a rare organic aciduria affecting ketone body metabolism and the catabolism of isoleucine and characterized by intermittent ketoacidotic episodes associated with vomiting, dyspnea, tachypnoea, hypotonia, lethargy and coma, with an onset during infancy or toddlerhood and usually ceasing by adolescence. The disease is beta-ketothiolase deficiency (MONDO_0008760, a Monarch Disease Ontology term). Also known as: 2-methyl-3-hydroxybutyricacidemia, 3-ketothiolase deficiency, 3-oxothiolase deficiency, Alpha methylacetoacetic aciduria, Alpha-methyl-acetoacetyl-CoA thiolase deficiency, BKT, T2 deficiency, alpha-methylacetoaceticaciduria.