Beckwith-Wiedemann syndrome : BWS Methylation-Specific MLPA

Test Information

BWS Methylation-Specific MLPA is a molecular test used to detect copy number variants or methylation abnormalities associated with Beckwith-Wiedemann syndrome.

Turnaround Time

3 weeks

CPT Code(s)

81401

Cost

$600

Genes

Clinical Information

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.

Indications

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.

Methodology

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.

Detection

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.

Specimen Requirements

5 to 7 ml of peripheral blood collected in an EDTA (lavender top) tube is the preferred specimen type. The minimal blood needed for reliable DNA isolation is 3 ml. Extracted DNA, dried blood spots, and saliva are also accepted for this test.

Transport Instructions

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 Testing Information

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.

Have Questions Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Methylation-Specific MLPA, Other Molecular Testing, Test Finder
One Mother's Story

One Mother's Story

After a long three-year struggle trying to have children, our son, Charlie, was born on April 18, 2009. He was our miracle...perfect in every way! When Charlie was five days old, our pediatrician called to notify us that one of the numbers from the heel prick test was a bit high. We headed to the hospital that afternoon for more tests. I will never forget the following day. It was cool and crisp - not a cloud in the sky....

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