The CRPPA gene provides instructions for making a protein that is involved in a process called glycosylation. Through this chemical process, sugar molecules are added to certain proteins. In particular, the CRPPA protein helps produce a molecule called ribitol 5-phosphate, which is an important component of the chain of sugar molecules added to a protein called alpha (α)-dystroglycan. Glycosylation is critical for the normal function of α-dystroglycan.~The α-dystroglycan protein helps anchor the structural framework inside each cell (cytoskeleton) to the lattice of proteins and other molecules outside the cell (extracellular matrix). In skeletal muscles, glycosylated α-dystroglycan helps stabilize and protect muscle fibers. In the brain, it helps direct the movement (migration) of nerve cells (neurons) during early development.