ornithine transcarbamylase deficiency

Ornithine transcarbamylase deficiency is an inherited disorder that causes ammonia to accumulate in the blood. Ammonia, which is formed when proteins are broken down in the body, is toxic if the levels become too high. The nervous system is especially sensitive to the effects of excess ammonia.

Ornithine transcarbamylase deficiency often becomes evident in the first few days of life. This severe, early-onset form of the disorder usually affects males; it is very rare in females. An infant with ornithine transcarbamylase deficiency may be lacking in energy (lethargic) or unwilling to eat, and have a poorly-controlled breathing rate or body temperature. Some babies with this disorder may experience unusual body movements, seizures, or coma. Complications from ornithine transcarbamylase deficiency may include developmental delay and intellectual disability. Progressive damage, skin lesions, and brittle hair may also occur.

In some affected individuals, signs and symptoms of ornithine transcarbamylase deficiency may be less severe, and may not appear until later in life. The later-onset form of the disorder occurs in both males and females. People with later-onset ornithine transcarbamylase deficiency may experience episodes of altered mental status, such as delirium, erratic behavior, or a reduced level of consciousness. Headaches, vomiting, aversion to protein foods, and seizures can also occur in this form of the disorder.