Carnitine palmitoyltransferase I deficiency is a condition that prevents the body from converting certain fats called long-chain fatty acids into energy, particularly during periods without food (fasting). Carnitine, a natural substance acquired mostly through the diet, is required by cells to process fats and produce energy. People with this disorder have a faulty enzyme that disrupts carnitine's role in processing long-chain fatty acids.
One of the main signs of this disorder is a low level of ketones, which are products of fat breakdown that are used for energy. Low blood sugar (hypoglycemia) is another major feature. Together these signs are called hypoketotic hypoglycemia, which can result in a loss of consciousness or seizures. People with this disorder typically also have an enlarged liver (hepatomegaly), muscle weakness, nervous system damage, and elevated levels of carnitine in the blood.
This condition is sometimes mistaken for Reye syndrome, a severe disorder that develops in children while they appear to be recovering from viral infections such as chicken pox or flu. Most cases of Reye syndrome are associated with the use of aspirin during these viral infections
This condition is rare; there are fewer than 50 individuals identified with this disorder. This disorder may be more common in the Hutterite populations of the northern United States and Canada, and in the Inuit populations of northern Canada, Alaska, and Greenland.
Mutations in the CPT1A gene cause carnitine palmitoyltransferase I deficiency.
Mutations in the CPT1A gene lead to the production of a defective version of an enzyme called carnitine palmitoyltransferase I. Together with carnitine, this enzyme normally helps transport long-chain fatty acids into mitochondria, the energy-producing centers within cells. If this enzyme is defective, long-chain fatty acids from food and fats stored in the body cannot be broken down and processed. As a result, these fatty acids are not converted into energy, which can lead to characteristic signs and symptoms of this disorder, such as weakness and hypoketotic hypoglycemia. Excess long-chain fatty acids may build up in tissues, damaging the liver, heart, and brain.
Read more about the CPT1A gene.
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
These resources address the management of carnitine palmitoyltransferase I deficiency and may include treatment providers.
You might also find information on treatment of carnitine palmitoyltransferase I deficiency in
Educational resources and Patient support.
- CPT deficiency, hepatic, type I
- CPT I deficiency
- Liver form of carnitine palmitoyltransferase deficiency
The resources on this site should not be used as a substitute for
professional medical care or advice. Users seeking information about
a personal genetic disease, syndrome, or condition should consult with a qualified
healthcare professional.
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