Late onset citrullinemias are a group of rare inherited metabolic disorders that are characterized by a deficiency in enzymes necessary for the breakdown and removal of waste substances from the body. These disorders specifically affect the metabolism of the amino acid citrulline, resulting in its accumulation and toxic buildup in various tissues and organs.
Late onset citrullinemias typically manifest in adolescence or adulthood, hence the term "late onset." These disorders are caused by mutations in genes that encode for enzymes involved in the urea cycle, a process that converts toxic ammonia into urea for elimination. As a result, individuals with late onset citrullinemias have impaired urea cycle function, leading to the buildup of ammonia and citrulline in the blood.
Symptoms of late onset citrullinemias can vary in severity and may include fatigue, confusion, headaches, seizures, behavioral changes, and recurrent episodes of high levels of ammonia in the blood (hyperammonemia). These symptoms often worsen during periods of increased protein intake or stress, as these conditions increase the production of ammonia.
Diagnosis of late onset citrullinemias typically involves a combination of clinical evaluation, blood tests to measure ammonia and citrulline levels, and genetic testing to identify specific mutations. Treatment generally involves a low-protein diet, medication to reduce ammonia levels, and supportive therapies such as dialysis or liver transplantation in severe cases.
Early detection and management of late onset citrullinemias are crucial in preventing long-term complications and improving quality of life for individuals affected by these disorders.
