Carnitine palmitoyltransferase I (CPT I) deficiency is a condition that prevents the body from using certain fats for energy.

Variants (also caused mutations) in the CPT1A gene cause CPT I deficiency. This gene provides instructions for making an enzyme called carnitine palmitoyltransferase 1A, which is found in the liver.

CPT I deficiency is a rare disorder, though its prevalence varies worldwide. It is estimated to occur in 1 in 750,000 to 2,000,000 infants in the United States. CPT I deficiency is more common in certain populations, including some Native Alaskan populations and some Native Pacific Island populations. In certain regions of China, CPT I deficiency is estimated to have an incidence of 1 in 102,388 infants.

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell must have a variant to cause the disorder. The parents of an individual with an autosomal recessive condition each carry one copy of the altered gene, but they typically do not show signs and symptoms of the condition. However, women who have one CPT1A gene variant and who are pregnant with a fetus who has two CPT1A gene variants are at risk of developing a condition called acute fatty liver of pregnancy (AFLP). AFLP begins with abdominal pain and can rapidly progress to liver failure.

Published Date: March 17, 2025
Published By: National Institutes of Health