Beckwith-Wiedemann Syndrome : CDKN1C Sequencing

Test Information

CDKN1C sequencing is a molecular test used to identify variants in the gene associated with Beckwith-Wiedemann Syndrome.

Turnaround Time

3 weeks

CPT Code(s)

81479

Cost

$500

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

Sanger Sequencing

Detection

5-10% of de novo cases of BWS will have a sequence alteration in the CDKN1C gene. Sequencing of this gene identifies a pathogenic maternally inherited variant in 40% of familial cases.

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

Molecular Testing, Sanger Sequencing
Lucy's Story

Lucy's Story

When our daughter Lucy had a metabolic crisis at 7 days old, we were shocked and devastated to find out that she was born with a rare genetic disorder (MSUD). Her newborn screening results did not make it back in time to prevent the crisis, and no one at our local hospital was familiar with the disease. They did not know how to treat her. Calls were made to Greenwood Genetic Center to confirm her diagnosis...

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