The FKTN gene provides instructions for making an enzyme called fukutin. This enzyme is present in many of the body's tissues, but it is particularly abundant in the heart, brain, and the muscles used for movement (skeletal muscles). Within cells, fukutin is found in a specialized structure called the Golgi apparatus, where newly produced proteins are modified.~Fukutin is involved in a protein modification process called glycosylation. Through this chemical process, sugar molecules are added to certain proteins. Fukutin works closely with other enzymes to add ribitol phosphate molecules to the chain of sugars already attached to a protein called alpha-dystroglycan. Glycosylation is critical for the normal function of alpha-dystroglycan.~The alpha-dystroglycan protein helps anchor the structural framework inside each cell (cytoskeleton) to a network of molecules outside the cell (extracellular matrix). In skeletal muscles, alpha-dystroglycan helps stabilize and protect muscle fibers. In the brain, alpha-dystroglycan helps direct the movement (migration) of nerve cells (neurons) during early development.