Carnitine palmitoyltransferase I deficiency

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

The signs and symptoms of CPT I deficiency are often brought on by episodes of increased energy demands in the body such as illness or periods of fasting. During these times, affected individuals usually develop low levels of glucose in the blood and a low level of ketones, which are normally produced when fats are broken down to be used for energy. Together, these signs are called hypoketotic hypoglycemia. This may cause individuals to experience confusion, seizures, or a lack of energy (lethargy).

People with CPT I deficiency can also develop an enlarged liver (hepatomegaly) that is not able to remove toxins from the blood efficiently. These toxins build up and can affect brain function (hepatic encephalopathy). As long as no brain damage occurs during these episodes of hepatic encephalopathy, individuals with CPT I deficiency often have normal development.

Health can decline quickly in people with CPT I deficiency. Affected individuals are encouraged to avoid prolonged fasting to prevent serious health problems. Individuals with CPT I deficiency are at risk for nervous system damage, liver failure, coma, and sudden death. These problems can begin any time between infancy to adulthood, though some individuals experience no health problems at all.

CPT I deficiency is often detected shortly after birth by newborn screening, which identifies abnormal levels of certain compounds in the blood. People with CPT I deficiency have high levels of a compound called carnitine. Cells use carnitine, a natural substance that is acquired mostly through the diet, to process fats and produce energy.