ESPE Abstracts

Background: Beta-ketothiolase deficiency is a rare autosomal recessive disease caused by ACAT1 gene mutation. Only 100 cases have been reported up to now.

Methods: Among the 13 patients, four were diagnosed in our institute, and 9 were from a literature review of all reported Chinese cases. Two patients were diagnosed with newborn screening, and the others were diagnosed after ketoacidotic episodes. Clinical characteristics, laboratory and molecular findings and outcome of the 13 Chinese patients were recorded.

Results: All patients had increased urine 2-methyl-3-hydroxybutyric acid, 2-methylacetoacetic acid, and tiglylglycine, or elevated blood levels of C5:1 and C5-OH carnitines. Eight patients were found with ACAT1 gene mutations. Except the two patients diagnosed by newborn screening, all patients were symptomatic and experiencing acute ketoacidotic episodes upon admission. Severe metabolic acidosis was found in eight patients or respiratory acidosis in two patients. Common triggers of the episodes included respiratory infections in and/or gastroenteritis. One patient died after the first ketoacidotic episode at eight months of age, and the other 11 patients had favorable outcomes.

Conclusions: Early diagnosis and treatment is very important for the favorable outcome. Patients with beta-ketothiolase deficiency may remain asymptomatic if with early diagnosis and preventive management.

Keywords: beta-ketothiolase deficiency, genetic testing, newborn screening, outcome