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?

Rhizomelic Chondrodysplasia Punctata Type 1/Refsum Disease

What Your Test Results Mean:

Test results indicate that you are a carrier of rhizomelic chondrodysplasia punctata type 1 (RCDP1)/Refsum disease. Carriers typically show no symptoms of RCDP1. Risk for current or future pregnancies is dependent on your partner’s carrier status. Carrier testing of your partner is recommended in addition to consultation with a genetic counselor for 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 and their own personal clinical management.

Disease Explained:

Rhizomelic chondrodysplasia punctata type 1 (RCDP1)/Refsum disease is an inherited condition that impairs the body’s ability to make plasmalogen, an important component of cell membranes. It is characterized by skeletal abnormalities, distinctive facial features, intellectual disability, and respiratory problems. There are three types, with type I being the most common. Type I rhizomelic chondrodysplasia punctata is caused by variants in the PEX7 gene, which is involved in the formation of function of the peroxisomes in the cell. Some of the skeletal features include shortening of the bones in the upper arms and thighs (called rhizomelic shortening), a bone abnormality called chondrodysplasia punctata that affects the growth of the long bones, and joint deformities called contractures which make the joints very stiff and painful. The facial features include a prominent forehead, widely spaced eyes, a sunken appearance to the middle of the face, a small nose with upturned nostrils, and full cheeks. People with this condition can also develop cataracts very early in life. Other features include significant developmental delay, severe intellectual disability, growth delay, seizures, recurrent respiratory infections, and life-threatening breathing problems.


RCDP1 has a very poor prognosis with death generally occurring during the first decade of life, mainly due to respiratory complications.


Management of this condition is usually focused on addressing specific symptoms; there is no cure. Physical therapy is usually recommended to assist in the improvement of contractures; orthopedic surgeries have also improved function in some individuals. Dietary restriction of phytanic acid to avoid the consequences of phytanic acid accumulation over time may be of benefit to some individuals with milder forms of this condition. Other management includes seizure control; vision, hearing, and orthopedic care; prevention of respiratory infections; and placement of a gastrostomy tube to assist with poor feeding and recurrent aspiration.

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