Joubert syndrome 2 occurs at increased frequency in the Ashkenazi Jewish population, with a carrier frequency of 1 in 92. Joubert syndrome 2 is characterized by a brain malformation with symptoms including cerebellar ataxia, significant developmental delay, hypotonia, and seizures. Other abnormalities of the digits, kidney and liver as well as facial clefting may also occur.
Couples who are planning a pregnancy or who are already pregnant may decide to have testing to find out if they are carriers and at risk of having a baby with Joubert syndrome 2. It is standard of care to offer carrier screening to individuals of Ashkenazi Jewish descent for Bloom syndrome, Canavan disease, cystic fibrosis, familial dysautonomia, Fanconi anemia group C, Gaucher disease, mucolipidosis type IV, Niemann-Pick disease type A and Tay-Sachs disease. If both parents are found to be carriers, prenatal diagnosis by CVS or amniocentesis is available. Our Joubert syndrome 2 mutation analysis tests for one mutation for a 99% carrier detection rate in the Ashkenazi Jewish population.
- ACD-A (yellow-top) or EDTA (lavender-top) tube.
- Adult: 10 ml whole blood, 30 ml whole blood if ordering multiple tests.
- Please Note: Patient should not eat, drink, smoke or chew gum for at least one hour prior to collection. (See specimen kit for detailed instructions). Mouthwash samples can be sent when ordering up to two tests. When ordering more than two tests, blood samples are required.
- 10 ml of Scope® mouthwash that has been swished vigorously for at least 1 minute.
- Collect in orange-top 50 ml polypropylene tube.
- Please Note: Call a laboratory genetic coordinator prior to obtaining any specimens. Prenatal testing is recommended only for carrier couples with identified mutations. In some circumstances, specimens from other family members may be required.
All prenatal specimens (including cord blood) must be accompanied by a maternal blood specimen or mouthwash for analysis of possible maternal cell contamination.
- Discard first 2 ml; then 10 ml amniotic fluid in 15 ml orange-top polypropylene tube, 10-15 mg chorionic villi in laboratory-provided screw-top tubes with sterile transport medium or one T-25 flask of confluent fetal cells.
- Additional specimen must be obtained for back-up culture at one of our cytogenetics laboratories or another facility.
- If additional testing is desired, more amniotic fluid is needed. For example, chromosome analysis requires an additional 15-25 ml (see Cytogenetics - Amniotic Fluid Chromosome Analysis test page) and AFAFP requires an additional 2 ml (see Amniotic Fluid Alpha-Fetoprotein (AFAFP) Testing test page).
Client Services: Reproductive Genetics 800-345-GENE (4363)
Specimen Services/Pickup: 877-246-1226
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