Beta-Ketothiolase Deficiency (ACAT1)

Beta-ketothiolase deficiency is an autosomal recessive disorder caused by pathogenic variants in the ACAT1 gene, and has the highest prevalence in the Caucasian and Asian populations. Patients with beta-ketothiolase deficiency can develop both acidosis (increased levels of acid in the body) and ketosis (the body uses fat for energy instead of sugar). Patients with acidosis can have seizures, lethargy, hepatomegaly, vomiting, coma, and, if untreated, death. In between episodes of acidosis, patients are generally healthy and have no symptoms. When they undergo stress such as fasting or extreme energy need, however, patients are at risk for developing severe ketoacidosis. During this crisis, they may develop any or all of the symptoms outlined; this can prove fatal without intervention. If they are closely monitored by an experienced medical team, patients may live a typical lifespan. There have been no reported genotype-phenotype correlations.

For information about carrier frequency and residual risk, please see the residual risk table.