Test Overview
Test Methodology

Multi-locus imprinting MS-MLPA (Methylation Specific Multiplex Ligation-dependent Probe Amplification) is used to determine the methylation status and the copy number at imprinted loci in 15q11.2 (5’ SNRPN).

Test Usage

Testing for or confirmation of diagnosis or suspicion of Prader-Willi or Angelman syndrome.

Reference Range *

Interpretive report provided.
*Reference ranges may change over time. Please refer to the original patient report when evaluating results.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

This assay is not able to identify the 11% of Angelman syndrome cases caused by defects in UBE3A or the other 10% of Angelman syndrome cases caused by unidentified genetic mechanism.

Test Details
Days Set Up
Various days Monday – Friday
Analytic Time

14 - 21 days

Soft Order Code
PWSMP
MiChart Code
Prader-Willi/Angelman Syndrome Analysis
Synonyms
  • Prader-Willi / Angelman Methylation Analysis
  • Prader-Willi / Angelman Methylation PCR
  • SNRPN Methylation Analysis
  • SNRPN Methylation PCR
  • Prader-Willi Syndrome
  • Angelman Syndrome
  • Autism / Intellectual Disability
Laboratory
MMGL
Section
MMGL Molecular Genetics
Specimen Requirements
Collection Instructions

Collect blood specimen in a EDTA lavender top tube. Send it within 24 hours if stored at room temperature or within 5 days if stored refrigerated.

Fill out a MLabs Molecular test requisition (or place an e-order if applicable):
https://mlabs.umich.edu/media/166
Fill out a Clinical History Form for Insurance Prior Authorization (include all required documentation indicated at the bottom of this form):
https://mlabs.umich.edu/sites/default/files/2020-08/file/mlab11618clini…
Fill out a UMHS Request and Consent for Genetic Testing form:
https://mlabs.umich.edu/sites/default/files/2023-04/file/germline-conse…
Michigan State law requires the ordering provider to obtaining informed consent from the patient prior to prognostic or predictive genetic testing. Contact a MLabs Client Services Center at 800-862-7284 to request paper copies or to setup a client account.

Alternate Specimen
Cheek swab kit (Oragene OCD-100), follow collection instructions.
Saliva kit (Oragene OGD-510), follow collection instructions.
Normal Volume
5 mL whole blood
Minimum Volume
1 mL whole blood (0.5 mL infants)
Storage Temperature
Room temperature up to 24 hours or 2-8°C up to 5 days for blood
2-36°C for saliva
Rejection Criteria
Hemolyzed blood sample. Fresh tissue (POC) or paraffin embedded specimens are not acceptable.
Additional Information

Aberrations affecting imprinted loci in 15q11-13 region, including deletions, uniparental disomy, or rare epimutations at imprinting center, account for more than 99% of Prader-Willi syndrome cases and approximately 80% of Angelman syndrome cases. These aberrations can be detected by MS-MLPA in the forms of abnormal methylation status and/or abnormal copy number at imprinted loci in 15q11.2 (5’ SNRPN gene). Depending on the specific abnormal results, additional tests including chromosomal microarray, uniparental disomy analysis and imprinting center sequencing may be needed to further determine the molecular mechanism.

Most insurance carriers require prior authorization for genetic testing. Testing will not begin until insurance prior authorization is received by the laboratory or it is confirmed that prior authorization is not required. The ordering health care provider can obtain the prior authorization or request the laboratory to submit it. To obtain BCN prior authorization call Joint Venture Hospital Laboratories (JVHL) at 800-445-4979; for all other insurances, contact the plan directly. By ordering this test the clinician acknowledges that informed consent, https://mlabs.umich.edu/sites/default/files/2023-04/file/germline-conse…, has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test includes medical geneticist interpretation of results billed as a separate additional charge. This test is not available without interpretation.

Billing
CPT Code
81331
Fee Code
DA030
Pro Fee CPT
G0452-26
NY State Approved
No