ARGININEMIA - A TREATABLE GENETIC CAUSE OF PROGRESSIVE SPASTIC DIPLEGIA SIMULATING CEREBRAL-PALSY - CASE-REPORTS AND LITERATURE-REVIEW

Argininemia, a rare autosomal recessive urea cycle disorder is caused by a deficiency of arginase, with resulting elevated plasma arginine a nd ammonia levels. Reports to date have focused little on the neurolog y of this disorder or the efficacy of treatments. A MEDLINE search rev ealed 25 previously reported cases, to which we have added two brother s who presented with late onset progressive spastic diplegia. Though t heir degree of enzyme deficiency was comparable, the severity of their phenotypic abnormalities differed substantially. With dietary therapy , both showed improved cognitive and motor function. Late metabolic cr ises occurred in both, resulting in death of the less severely affecte d brother. Based on analysis of our clinical database, we report on th e full spectrum of neurologic abnormalities seen in argininemia with p articular focus on the accompanying progressive spastic diplegia and i ts response to treatment; progressive decline in head growth; distinct ive neuroradiologic findings; and life-threatening later complications . Current and potential future therapies and long-term outcome are sum marized.