Citrullinemia Type 1: Behavioral Improvement with Late Liver Transplantation

Citrullinemia Type 1 (also known as classic citrullinemia) is a rare autosomal recessive urea cycle disorder due to reduced activity of argininosuccinate synthetase 1; characterized by hyperammonemia leading to neurological damage. The authors report a case of an 8-y boy who was diagnosed with Citrullinemia Type 1 at birth which was anticipated prenatally due to family history. His diagnosis was confirmed as a homozygous mutation (Exon 15: c.1168G > A (p.G390R)) of ASS gene. Inspite of being on a protein-free diet and ammonia scavenging treatment; the patient developed recurrent episodes of encephalopathy and seizures; complicated with behavioral issues. The patient underwent living related liver-transplantation from his mother (heterozygous carrier of the same mutation). Peri-transplant management of ammonia and plasma amino acid levels is challenging and has been highlighted. It is important to consider liver transplantation as it corrects the genetic deficiency of ASS resulting in the reversal of neuro-behavioral changes, as was seen in index patient.