Late onset citrullinemia, also known as adult-onset citrullinemia or type II citrullinemia, is a rare genetic disorder characterized by abnormal levels of the amino acid citrulline in the body. It is caused by a deficiency of the enzyme argininosuccinate synthetase (AS), which is responsible for the conversion of citrulline into argininosuccinate.
Unlike the classical form of citrullinemia, which typically presents in infancy, late onset citrullinemia usually manifests during adolescence or adulthood, hence its name. Symptoms may include recurrent episodes of vomiting, liver dysfunction, mental confusion, and neuropsychiatric abnormalities. These symptoms are often triggered by factors such as fasting, infections, or medications that place additional stress on the body's metabolism.
Late onset citrullinemia is inherited in an autosomal recessive manner, meaning that an affected individual inherits two defective copies of the responsible gene, one from each parent who are carriers. Genetic testing can confirm the diagnosis, and early detection is crucial to prevent life-threatening episodes and manage the condition effectively.
Treatment of late onset citrullinemia involves a combination of dietary restriction and medication. Protein intake must be carefully monitored and limited to reduce the production of citrulline. Medications such as sodium benzoate and sodium phenylacetate may also be prescribed to help remove excess ammonia from the body. Additionally, regular monitoring and follow-up with a specialized healthcare team, including geneticists, dieticians, and hepatologists, is essential to manage this complex disorder effectively and mitigate long-term complications.
