Lysinuric Protein Intolerance Presenting with Recurrent Hyperammonemic Encephalopathy.

Background: Lysinuric protein intolerance is an inherited disorder of transport of cationic amino acids, causing amino aciduria. Case characteristics: A 3-year-old boy with 12 month history of episodic change in behavior (decreased sleep, poor interaction), stunted growth and hyperammonemia. Outcome: Genetic analysis revealed a homozygous mutation, c.158C>T (p.Ser53Leu) in exon 1 of SLC7A7 gene.With appropriate management of hyperammonemia episodes, his neurodevelopmental outcome is normal. Message: Lysinusic protein intolerance is a potentially treatable disorder and should not to be missed.