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.