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From SNPedia
Citrullinemia type II/citrin deficiency; neonatal and/or adult-onset
Is agenotype
Geno Mag Summary
(A;A) 5.7 Citrullinemia type II/citrin deficiency; neonatal and/or adult-onset
(A;G) 3 Carrier of a citrullinemia/citrin deficiency allele
(G;G) 0 common in clinvar

Pathogenic in ClinVar;see sidebar on main SNP page. This is a genotype with recommended actions if clinically confirmed. In brief:

  • CTLN2 can appear suddenly in children or adults as recurrent hyperammonemia with neuropsychiatric symptoms.
  • To prevent hyperammonemia a diet rich in protein and lipids and low in carbohydrates is recommended. Diet composition consultation and a medical genetics consultation are recommended. However, the effectiveness of dietary treatment prior to the onset of symptoms of CTLN2 is unknown.
  • Alcohol, acetaminophen and rabeprozole may trigger CTNL2.
  • Arginine and sodium pyruvate administration may be effective in preventing hyperammonemic crises (by reducing blood ammonia concentrations) and fatty liver, thereby delaying the need for liver transplantation.
  • Liver transplantation is the most successful therapy to date for symptomatic patients. More recently, some reports indicate that arginine and sodium pyruvate administration combined with a carbohydrate-restricted diet may be an effective therapy.
  • Should severe brain edema occur, avoid treatment with glycerol-containing osmotic agents.
  • Determining the genetic status of at-risk relatives could allow an infant's diet to be managed for citrin deficiency before symptoms occur.

The full ClinGen Actionability report about adult-onset type II citrullinemia (CTLN2) can be found here.

Genetic counseling may be available to you through your health-care network. In the US, genetic counselors may be found via this webpage of the National Society of Genetic Counselors.