They result from a deficiency in PRODH and P5 enzymes in type I and type II hyperprolinemias, and plasma proline concentrations range from 500 to 1,000 μmol/L and 1,500 to 3,000 μmol/L, respectively.14, 15, 16 These conditions are associated with congenital renal anomalies, deafness, and neurological disorders, but not with tubular injuries resulting from high proline concentration.14 This evidence concerns the gene PRODH and nervous system disorder.