Hereditary carnitine deficiency

Hereditary Carnitine Deficiency

Hereditary carnitine deficiency, also known as primary carnitine deficiency, is a genetic disorder that affects the body's ability to utilize fats for energy. This condition is caused by mutations in the SLC22A5 gene, which encodes the protein responsible for transporting carnitine into cells. Carnitine is a nutrient that is essential for the transport of long-chain fatty acids into the mitochondria, where they are oxidized to produce energy.

Pathophysiology

The primary defect in hereditary carnitine deficiency is the impaired transport of carnitine into cells due to mutations in the SLC22A5 gene. This results in low levels of carnitine in the blood and tissues, leading to an inability to properly metabolize fatty acids. As a consequence, the body relies more heavily on glucose for energy, which can lead to hypoglycemia, especially during periods of fasting or illness.

Clinical Presentation

Individuals with hereditary carnitine deficiency may present with a variety of symptoms, which can vary in severity. Common clinical features include:

-Muscle weakness: Due to impaired energy production in muscle cells. -Hypoglycemia: Low blood sugar levels, particularly during fasting. -Cardiomyopathy: Enlargement and weakening of the heart muscle. -Hepatomegaly: Enlargement of the liver. -Failure to thrive: Poor growth in infants and children.

Diagnosis

Diagnosis of hereditary carnitine deficiency is typically made through a combination of clinical evaluation, biochemical testing, and genetic analysis. Key diagnostic tests include:

-Plasma carnitine levels: Measurement of free and total carnitine in the blood. -Genetic testing: Identification of mutations in the SLC22A5 gene. -Acylcarnitine profile: Analysis of acylcarnitines in the blood to assess fatty acid oxidation.

Treatment

The primary treatment for hereditary carnitine deficiency is carnitine supplementation. Oral L-carnitine is administered to increase carnitine levels in the blood and tissues, thereby improving fatty acid metabolism. Additional management strategies may include dietary modifications to avoid fasting and to ensure adequate caloric intake.

Prognosis

With early diagnosis and appropriate treatment, individuals with hereditary carnitine deficiency can lead relatively normal lives. However, untreated or late-diagnosed cases may result in serious complications, including heart failure and metabolic crises.

Also see

- Fatty acid oxidation disorders - Carnitine palmitoyltransferase deficiency - Metabolic myopathies - Hypoglycemia