Argininosuccinic aciduria

Argininosuccinic aciduria is an inherited disorder that causes the accumulation of argininosuccinic acid in the blood and urine. Some patients also have raised ammonia, a toxic chemical that can affect the nervous system. It may become evident in the first few days of life because of high blood ammonia, or later in life with sparse or brittle hair, developmental delay and tremors. An affected infant may seem lethargic or unwilling to eat, or have seizures, and complications can include developmental delay, progressive liver damage and skin lesions. Immediate treatment and lifelong management with a strict diet and supplements may prevent many complications, and a mild form may raise ammonia only during illness or stress.