This is the situation in argininosuccinic aciduria, despite the fact that formation of this substance ensures incorporation of the 2 waste nitrogen molecules normally found in urea. In any case, the rapid clearance of ASA in urine has given the name to the disease, although elevations of ASA can be found in plasma. Hyperammonemia in this disease presents with the typical findings and has all of the attendant consequences seen in the other diseases of this category. As with other disorders in this category, this deficiency can present in the neonate or later in life, and true incidence cannot be cited without population screening data. Inherited as an autosomal recessive trait, argininosuccinic aciduria affects both sexes equally.
Newborn presentation is consistent with hyperammonemia.
The multiple primary causes of hyperammonemia, specifically due to urea cycle enzyme deficiencies, vary in presentation, diagnostic features, and treatment. The most striking clinical findings of each individual urea cycle disorder consequently relate to the foregoing constellation of symptoms and their temporal sequence. Delayed development and mental retardation are certain long-term consequences in survivors who do not receive proper treatment. Poor growth may be evident. Pulmonary Tachypnea or hyperpnea may be present.