What Does NxGen MDx Screen For?

We screen for up to 120 genetic disorders that can affect your pregnancy, the health of your baby, and your family's future. You can learn more about our various screens — and which sets of screens (or "panels") align with where you are in your reproductive journey.

What Does NxGen MDx Screen For?

Citrullinemia Type 1

What Your Test Results Mean:

Test results indicate that you are a carrier of citrullinemia type 1. 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 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 is symptomatic as there is no cure for citrullinemia type 1. Treatment focuses on reducing blood ammonia levels through diet, medication, and dialysis.

Which Screens Are Right for You?

Determining which screens or set of screens are right for you will depend on where you are in your reproductive journey. Tell us where you are today so you can learn more about how to move forward tomorrow.

Planning to Have a Baby Already Expecting
Which Screens Are Right for You?

Talk to a Genetic Counselor

As a NxGen client, you'll have access to personal genetic counselors who can help explain the results of your screens and provide insight on how to move forward. To schedule a personal conference to discuss your screen results, call (855) 776-9436. or click the link below.

Discuss Your Screening Results