Milder form of urea cycle defect revisited: Report and review of hyperornithinaemia-hyperammonaemia-homocitrullinuria (HHH) syndrome diagnosed in a teenage girl presenting with recurrent encephalopathy

Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome (OMIM #238970) is a rare autosomal recessive disorder associated with mutations of the SLC25A15 gene which encodes the mitochondrial ornithine transporter 1 (ORNT1).