carnitine palmitoyltransferase II deficiency

Carnitine palmitoyltransferase II deficiency is an inherited metabolic disorder that affects the body’s ability to oxidize long chain fatty acids within mitochondria. The condition is caused by pathogenic alterations in the CPT2 gene, which encodes a key enzyme involved in energy production from fats. While the disorder can present in various forms including infantile and neonatal types, the myopathic form is commonly observed later in life. This condition is uncommon, affecting approximately 1 to 9 per 100,000 individuals.

Individuals with CPT II deficiency frequently experience muscle-related symptoms, with muscle weakness, myalgia, and exercise intolerance being the most characteristic. During or after periods of physical exertion, many patients suffer from exercise-induced muscle cramps and pain, accompanied by episodes of myoglobinuria and red-brown urine that indicate muscle breakdown. In addition, some individuals may report less common features such as seizures, headache, and even signs of renal impairment. Not all individuals experience all features, and severity varies considerably.

This condition is caused by pathogenic variants in the CPT2 gene, which encodes carnitine palmitoyltransferase II, an enzyme essential for the mitochondrial oxidation of long chain fatty acids. Disruption in this enzyme’s function impairs the body’s ability to derive energy from fats, particularly under conditions of prolonged exercise or fasting. Although a clear inheritance pattern is not provided, confirmation of the diagnosis is achieved through genetic testing that identifies these CPT2 alterations.

Currently, management of CPT II deficiency focuses on supportive care and individualized symptom management. While no treatments have been specifically approved for this condition, care is typically tailored to reduce muscle stress by incorporating dietary modifications, avoiding prolonged fasting, and moderating exercise intensity. Regular surveillance is an essential part of long-term care, helping to detect complications such as renal issues or episodes of rhabdomyolysis at an early stage. A multidisciplinary team approach, along with genetic counseling, is recommended to help families navigate treatment options and ongoing management.

Outcomes in CPT II deficiency are variable, with the clinical course ranging from relatively mild, exercise-induced symptoms to more significant complications affecting muscle function and other organ systems. With current standards of care, many individuals manage their symptoms effectively, although regular monitoring remains critical to prompt intervention when complications occur. Outcomes described in medical literature continue to evolve as standards of care improve. Families often find it helpful to connect with specialists familiar with this condition for ongoing management and support.

Several clinical trials are underway exploring new treatment approaches for CPT II deficiency, with investigators evaluating interventions aimed at improving energy metabolism and reducing muscle-related complications. Active research is shedding light on potential therapies that may offer further benefits over supportive care. Individuals interested in clinical trials can search ClinicalTrials.gov or consult their healthcare team about eligibility.