Hyperammonaemia

Gene: SLC25A15

Green List (high evidence)

Hyperornithinemia-hyperammonemia-homocitrullinuria syndrome (HHHS) is an autosomal recessive, chronic and progressive disorder of the urea cycle with typical age of onset in early life. The acute phase is characterized by hyperammonemia accompanied by vomiting, ataxia, lethargy, confusion, and coma. Chronically, aversion to protein-rich foods, coagulation abnormalities, hypotonia, developmental delay, progressive encephalopathy with mental regression, and signs of motor dysfunction are present. About 95% of patients survive after diagnosis and therapy is established. However, in early adulthood most patients develop signs of pyramidal tract dysfunction.

Well established gene-disease association. More than 50 families reported.

Created: 10 Apr 2022, 10:54 p.m. | Last Modified: 10 Apr 2022, 10:54 p.m.

Panel Version: 0.12827

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Hyperornithinemia-hyperammonemia-homocitrullinemia syndrome , MIM#238970

Publications

• 10369256
• 19242930]