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?

3-Methylglutaconic Aciduria Type III (Costeff Optic Atrophy)

What Your Test Results Mean:

Test results indicate that you are a carrier of 3-methylglutaconic aciduria type III (Costeff optic atrophy). Carriers are not expected to show symptoms. You and your partner would both have to be carriers of Costeff optic atrophy 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:

Costeff optic atrophy is an inherited condition characterized by vision loss, delayed development, and movement problems. Vision loss is primarily caused by degeneration (atrophy) of the optic nerves, which carry information from the eyes to the brain. This typically begins in infancy or early childhood and results in vision impairment that worsens over time.

Development of motor skills such as walking is often delayed in people with Costeff optic atrophy. Affected individuals may also have speech difficulties (dysarthria). While some people with Costeff optic atrophy have mild to moderate intellectual disability, many have normal intelligence.

Movement problems in people with Costeff optic atrophy develop in late childhood and include muscle stiffness, impaired muscle coordination (ataxia), and involuntary jerking movements. As a result of these movement difficulties, individuals with Costeff optic atrophy may require wheelchair assistance.


While some individuals with this condition have been known to live into their thirties, life expectancy beyond that is unknown.


Treatment is supportive. A multidisciplinary team including a neurologist, orthopedic surgeon, ophthalmologist, geneticist, and physical therapist is required for the care of affected individuals.

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.

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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