What Your Test Results Mean:

Carriers are not expected to show symptoms. You and your partner would both have to be carriers of citrullinemia type 1 for there to be an increased chance to have a child with symptoms; this is known as autosomal recessive inheritance. Carrier testing of your partner or donor is recommended in addition to consultation with a genetic counselor for a more detailed risk assessment.

Since this is an inherited gene change, this information may be helpful to share with family members as it may impact their family planning.

Disease Explained:

Citrullinemia type 1 is an inherited metabolic disorder caused by excess nitrogen build up in the body. The excess nitrogen typically takes the form of ammonia and accumulates to toxic levels in the bloodstream. Infants appear normal at birth and start to show symptoms by the first week of life. Symptoms include lethargy (lack of energy), vomiting, seizures, pressure around the brain, and poor feeding. If left untreated, signs and symptoms can worsen and become life-threatening. A less-common, milder form of citrullinemia type 1 presents with symptoms later in life and causes headaches, ataxia (issues with balance and muscle coordination), partial loss of vision, and lethargy.

Prognosis:

Prognosis is not well defined. If left untreated, citrullinemia type 1 can be fatal early in infancy. With treatment, individuals with citrullinemia type 1 can survive for an unknown amount of time, but treatment cannot reverse neurological impairment.

Treatment:

Treatment is symptomatic as there is no cure for citrullinemia type 1. Treatment focuses on reducing blood ammonia levels through diet, medication, and dialysis.