Angelman Syndrome Methylation-Specific MLPA

Test Information

Angelman syndrome Methylation-Specific MLPA is a molecular test used to detect copy number variants and methylation abnormalities associated with Angelman syndrome.

Turnaround Time

3 weeks

CPT Code(s)

81331

Cost

$600

Clinical Information

Angelman syndrome is an example of a disorder involving imprinted genes. Imprinted genes are only expressed from either the maternally or paternally derived member of a homologous chromosome pair. Angelman syndrome is characterized by significant developmental delay or intellectual disability, severe speech impairment, an ataxic gait, and inappropriate happy behavior including excessive laughing and smiling. Other physical concerns include microcephaly, seizures, wide mouth and a prominent mandible. Angelman syndrome is caused by the lack of expression of the maternally inherited region of chromosome 15 (15q11.2-q13). This lack of expression can be caused by a deletion of the maternal chromosome, paternal uniparental disomy (UPD), a mutation in the UBE3A gene in this region, or an imprinting defect.

Indications

Methylation testing and copy number status is useful to confirm the diagnosis. Further testing may be necessary to determine the etiology of the disorder and 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 15q11.2-q13 as well as any copy number variants in this region. If an abnormal methylation pattern is identified, then pyrosequencing is performed to quantify the methylation at these sites as needed.

Detection

Methylation analysis for Prader-Willi/Angelman syndromes will detect nearly all cases of Prader-Willi syndrome and approximately 78% of patients with Angelman syndrome.

Specimen Requirements

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.

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. 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
Falecia Thomas, MS, CGC

Meet Ella

We will remember February 26th for the rest of our lives. On that day, we received the call from the Greenwood Genetic Center that they had discovered our daughter, Ella Marie, has Kleefstra syndrome. Very early on, my wife, Kelly, observed Ella being delayed in some of her milestones. Kelly monitored Ella’s progression and sought out testing in an effort to get Ella some assistance. Along the way, we were sent to GGC and met with Dr. Roger St...

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