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.
Joubert Syndrome 2/TMEM216-Related Disorders
What Your Test Results Mean:
Carriers are not expected to show symptoms. You and your partner or donor would both have to be carriers of Joubert syndrome 2/TMEM216-related disorders 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.
Joubert syndrome 2 and TMEM216-related disorders are inherited, multisystem disorders caused by a defect in the cilia. The diseases are characterized by abnormal development of regions near the back of the brain (molar tooth sign), hypotonia, and developmental delays. Other symptoms can include infant breathing abnormalities, eye abnormalities such as retinal dystrophy, skeletal anomalies such as polydactyly, and kidney or liver disease.
A condition called Meckel syndrome 2 has also been associated with variants in the TMEM216 gene. Meckel syndrome is a disorder with severe signs and symptoms that affect many parts of the body. The most common features are enlarged kidneys with numerous fluid-filled cysts; an occipital encephalocele, which is a sac-like protrusion of the brain through an opening at the back of the skull; and the presence of extra fingers and toes (polydactyly). Most affected individuals also have a buildup of scar tissue (fibrosis) in the liver.
Prognosis for Joubert syndrome 2 is generally unfavorable. Affected individuals typically have significant psychomotor and cognitive delays, as well as oral motor difficulties resulting in swallowing and chewing difficulties. Some individuals experience end-stage renal insufficiency by mid-adolescence.
Prognosis for Meckel syndrome 2 is also unfavorable. Because of their serious health problems, most individuals with Meckel syndrome die before or shortly after birth. Most often, affected infants die of respiratory problems or kidney failure.
Treatment typically involves supportive care, as there is no cure for Joubert syndrome 2/TMEM216-related disorders. Surgical interventions may be considered for physical anomalies such as oral clefting, polydactyly, and hydrocephalus.
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