SLC22A5 (Solute Carrier Family 22 Member 5): SLC22A5 is a protein, also known as OCTN2, that functions as a key carnitine transporter in the body. It facilitates the cellular uptake of carnitine, a compound essential for moving fatty acids into mitochondria for energy production. This process is critical for energy metabolism in tissues such as the heart and muscles. Mutations in the SLC22A5 gene can result in primary carnitine deficiency, a condition marked by muscle weakness and cardiomyopathy, highlighting its vital role in metabolic health and energy balance.