Carnitine-acylcarnitine translocase deficiency is a rare genetic disorder that affects the body's ability to transport fatty acids into the mitochondria, the energy-producing structures in cells. This condition is caused by mutations in the SLC25A20 gene, which encodes the protein responsible for this transport process. As a result, individuals with this deficiency may experience low energy levels, muscle weakness, and other metabolic issues. Symptoms often appear in infancy or early childhood and can include hypoglycemia, lethargy, and cardiomyopathy. Diagnosis typically involves blood tests to measure levels of carnitine and acylcarnitines. Treatment focuses on managing symptoms and may include dietary changes and supplementation with carnitine to help improve energy metabolism.