Recurrent stupor due to lysinuric protein intolerance

Recurrent stupor in children is an uncommon clinical problem with a wide differential diagnosis; inherited metabolic disorders account for a vast majority. We report a 9-year-old girl with recurrent episodes of stupor. Initial episode was treated as viral encephalitis and the second episode was managed as non-convulsive status epilepticus. Hyperammonemia was detected in the last episode. Metabolic work-up after dietary protein challenge revealed classical biochemical features of lysinuric protein intolerance. She was managed with protein-restricted diet, which resulted in marked neurological improvement. LPI is a rare inherited metabolic disorder due to membrane transport defect of cationic amino acids.