Is hyperprolinemia type I actually a benign trait? Report of a case with severe neurologic involvement and vigabatrin intolerance

Hyperprolinemia type I is a deficiency of proline oxidase, (McKusick 23950) , leading to hyperprolinemia and iminoglycinuria, usually with renal involv ement. Hyperprolinemia type I is considered a benign trait. We reported a c ase of hyperprolinemia type I with a severe neurologic disorder and without renal involvement. The patient had marked psychomotor delay and right hemi paresis. Epilepsy was characterized by status epilepticus or a cluster of s eizures. Laboratory findings revealed elevated levels of proline in the ser um, urine, and cerebrospinal fluid without Delta (1)-pyrroline 5-carboxylat e dehydrogenase in the plasma or urine. Fluorescence in situ hybridization excluded a chromosome 22q11 deletion. Vigabatrin inhibits ornithine, transa minase. Thus, vigabatrin could lead to a depletion of the normal pool of py rroline 5-carboxylate dehydrogenase and could aggravate the clinical condit ion of the child. In this study, vigabatrin was discontinued. In the follow ing months, the patient had marked psychomotor improvement, without modific ation of the epilepsy. We suggest that vigabatrin should be avoided in hype rprolinemia type I.