Methylacetoacetyl-coenzyme A thiolase (MAT) deficiency is
an autosomal recessive disease caused by a defect of
mitochondrial acetoacetyl-CoA thiolase (T2). There is an
error of isoleucine catabolism and ketone body utilization
due to mutations in the acetyl-Coenzyme A acetyltransferase
1 (ACAT1) gene. We report a case of a 14 months old
Sabahan boy with beta deficiency who presented with
severe sepsis and ketoacidosis who subsequently
recovered..