Beta-ketothiolase deficiency

Beta-ketothiolase deficiency is an inherited disorder in which the body cannot effectively process a protein building block (amino acid) called isoleucine. This disorder also impairs the body's ability to process ketones, which are molecules produced during the breakdown of fats.

The signs and symptoms of beta-ketothiolase deficiency typically appear between the ages of 6 months and 24 months. Affected children experience episodes of vomiting, dehydration, difficulty breathing, extreme tiredness (lethargy), and, occasionally, seizures. These episodes, which are called ketoacidotic attacks, sometimes lead to coma. Ketoacidotic attacks are frequently triggered by infections or periods without food (fasting), and increased intake of protein-rich foods can also play a role.

Other names

2-methyl-3-hydroxybutyricacidemia; 2-methylacetoacetyl-coenzyme A thiolase deficiency; 3-alpha-oxothiolase deficiency; 3-ketothiolase deficiency; 3-oxothiolase deficiency; Alpha-methylacetoacetic aciduria; MAT deficiency; Methylacetoacetyl-coenzyme A thiolase deficiency; Mitochondrial 2-methylacetoacetyl-CoA thiolase deficiency – potassium stimulated; Mitochondrial acetoacetyl-CoA thiolase deficiency; T2 deficiency; Β-ketothiolase deficiency

Inheritance pattern

Autosomal recessive

Related genes

ACAT1

Source: MedlinePlus Genetics, U.S. National Library of Medicine.