Additional findings_Adult
Gene: ASS1
Approximately 1/3 of individuals present with late onset.
Hyperammonaemia can be triggered by protein overload, catabolic events (including pregnancy), or certain drugs and can lead to neurological deficits. Liver failure is now recognized as a primary presentation. Hepatic dysfunction, when present, is often noted at the time of initial hyperammonaemic episode but has also developed in individuals not experiencing significant hyperammonemia.
The mainstay of long-term management is dietary treatment based on minimizing the nitrogen load on the urea cycle under the expertise of a specialist metabolic dietician; may also include nitrogen scavengers.
Elective surgery should be performed in centers with a metabolic department including emergency treatment options for hyperammonaemia. Steroids and valproate contraindicated.
Sources: LiteratureCreated: 11 Apr 2025, 6:21 p.m.
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
Citrullinemia MIM#215700
Gene: ass1 has been classified as Green List (High Evidence).
Phenotypes for gene: ASS1 were changed from Citrullinemia MIM#215700 to Citrullinaemia MIM#215700
Gene: ass1 has been classified as Green List (High Evidence).
gene: ASS1 was added gene: ASS1 was added to Additional findings_Adult. Sources: Literature Mode of inheritance for gene: ASS1 was set to BIALLELIC, autosomal or pseudoautosomal Phenotypes for gene: ASS1 were set to Citrullinemia MIM#215700 Review for gene: ASS1 was set to GREEN