Carnitine palmitoyltransferase IA (CPT IA) deficiency is an inherited disorder in which the body is unable to use certain types of fats for energy. This is due to a deficiency of the enzyme carnitine palmitoyltransferase IA. Onset of symptoms is usually in infancy or childhood, beginning with poor appetite, irritability, fatigue, followed by more serious symptoms of low blood sugar, fever and vomiting. If left untreated, a child with CPT IA can then develop liver failure, seizures, coma leading to sudden death. Appearance of symptoms tends to be episodic and is usually triggered by periods of fasting or illness. Affected individuals are developmentally and cognitively normal between episodes, however recurrent episodes can cause brain damage, resulting in learning problems or intellectual disability. The life expectancy of individuals with CPT IA is not affected if fasting and intense exercise is avoided. CPT IA deficiency is caused by pathogenic variants in the CPT1A gene.