Test Overview

Test Methodology

Bisulfite conversion and PCR amplification to detect abnormal methylation patterns in the SNRPN gene.

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.

Test Limitations

Causal mutations or alterations that do not affect SNRPN gene methylation imprinting status will not be detected by this assay.

Test Details

Days Test Performed

Monday - Friday

Analytic Time

14 - 21 days

Soft Order Code


MiChart Code

Prader-Willi/Angelman Syndrome by PCR



Generic Peds Genetics Test
Prader-Willi / Angelman Methylation Analysis
Prader-Willi / Angelman Methylation PCR
SNRPN Methylation Analysis
SNRPN Methylation PCR
Prader-Willi Syndrome
Angelman Syndrome
PWS/AS crit reg M-PCR Shadow
Autism / Intellectual Disability

+ See More



Looking to Order a Test?

We’ve provided helpful links to make ordering easy.

Find a Requisition

All specimens should be accompanied by a requisition.

Submitting Specimens

Learn about how to properly label and where to ship specimens.

Order Kits and Supplies

MLabs provides all the supplies necessary for the collection of specimens.

Test FAQ

Visit our provider FAQ and learn about common questions to ordering tests.

Specimen Requirements

Offsite Collection Instructions

Collect specimen in a lavender top tube. Send intact specimen within 24 hours if stored at room temperature or within 5 days if stored refrigerated. Include the patient's family history, pedigree, and ethnicity on the test requisition. Obtaining informed consent from the patient prior to genetic testing is strongly recommended. If desired, a UMHS Request and Consent for Genetic Testing form can be obtained from the MMGL Molecular Genetics Laboratory by contacting the MLabs Client Services Center at 800-862-7284 or online at https://mlabs.umich.edu/sites/default/files/2020-01/file/pci-mmgl_infor….


Lavender Top Tube

Normal Volume

5 - 10 mL EDTA whole blood

Minimum Volume

2 mL EDTA whole blood

Additional Information

Aberrations in the 15q11-13 critical region including deletions, uniparental disomy, or rarely imprinting center mutations, account for 99% of individuals with Prader-Willi syndrome and approximately 80-85% of individuals with Angelman syndrome, and can be detected as abnormal methylation of the SNRPN gene. After an abnormal SNPRN result, additional analyses including FISH, UPD analysis and imprinting center sequencing may be needed to determine the molecular mechanism. By ordering this test the clinician acknowledges that informed consent 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 Information

Fee Codes

CPT Code


Have More Billing Questions?

Explore our helpful billing resources:

Billing Resources

Billing FAQ