BWS Methylation-Specific MLPA is a molecular test used to detect copy number variants or methylation abnormalities associated with Beckwith-Wiedemann syndrome.
3 weeks
81401
$600
BWS is the most common overgrowth syndrome characterized by large organs and body size. Macroglossia, ear lobe creases, helical creases, and omphalocele are common features as well. Patients with BWS are at an increased risk for embryonal tumors in childhood. These individuals typically have normal intelligence and attain a normal height and weight in adulthood. BWS is casued by alterations in methylation at two imprinting centers at 11p15.5.
Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.
A methylation sensitive multiplex ligation-dependent probe amplification (MLPA) assay is used to determine methylation status at the two imprinting centers and to identify microdeletions or duplications. If an abnormal methylation pattern is identified, then pyrosequencing is performed to quantify the methylation at these sites.
This testing will detect approximately 75% of cases of BWS. This includes about 55% of cases with an isolated imprinting defect, 20% of cases with paternal UPD, and less than 1% of cases with a deletion or duplication.
The preferred sample type is 3-5 ml of peripheral blood collected in an EDTA (purple top) tube. Extracted DNA and saliva are also accepted for this test. Saliva samples must be submitted in an approved saliva kit. Contact the lab to receive a saliva kit or to have one sent to your patient.
The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.
Prenatal diagnosis is available if the familial mutations are known or there are clinical features identified via ultrasound suggestive of a diagnosis in the fetus. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.
Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Falecia Thomas, MS, CGC
Alex Finley, MS, CGC