Defects in RPIA are the cause of ribose 5-phosphate isomerase deficiency (RPID) [MIM:608611]. A patient has been described with a deficiency of ribose 5-phosphate isomerase who presented with leukoencephalopathy and peripheral neuropathy. Proton magnetic resonance spectroscopy of the brain revealed a highly elevated level of the polyols ribitol and D-arabitol, which were subsequently also found in high concentrations in body fluids. Deficient activity of RPIA, one of the pentose phosphate pathway enzymes, has been demonstrated in fibroblasts.
Belongs to the ribose 5-phosphate isomerase family.