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Test Code MISCLM Prader-Willi/Angelman Syndrome, Molecular Analysis

Additional Codes

 

MAYO Test ID

PWAS

EPIC Test ID

LAB2608

 

Useful For

Confirmation of diagnosis in patients suspected of having either Prader-Willi syndrome (PWS) or Angelman syndrome (AS) based on clinical assessment or previous laboratory analysis

 

Prenatal diagnosis in families at risk for PWS or AS

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
CULAF Amniotic Fluid Culture/Genetic Test Yes No
MATCC Maternal Cell Contamination, B Yes No

Testing Algorithm

For prenatal specimens only: If amniotic fluid (nonconfluent cultured cells) is received, amniotic fluid culture/genetic test will be added and charged separately. For any prenatal specimen that is received, maternal cell contamination studies will be added.

 

See Prader-Willi and Angelman Syndromes: Laboratory Approach to Diagnosis in Special Instructions.

Method Name

Methylation-Sensitive Multiple Ligation-Dependent Probe Amplification (MLPA)
(PCR is utilized pursuant to a license agreement with Roche Diagnostic Systems, Inc.)

Reporting Name

Prader Willi/Angelman Mol Analysis

Specimen Type

Varies


Additional Testing Requirements


Mayo Medical Laboratories highly recommends that this test be ordered along with a routine chromosomal microarray analysis, CMACB / Chromosomal Microarray, Congenital, Blood, if the diagnosis of PWS or AS is not certain and chromosome analysis has not already been done.

 

All prenatal specimens must be accompanied by a maternal blood specimen. Order MATCC / Maternal Cell Contamination, Molecular Analysis on the maternal specimen.



Shipping Instructions


Specimen preferred to arrive within 96 hours of collection.

 

Prenatal specimens can be sent Monday through Thursday and must be received by 5 p.m. CST on Friday in order to be processed appropriately.



Specimen Required


Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call Mayo Medical Laboratories for instructions for testing patients who have received a bone marrow transplant.

 

Submit only 1 of the following specimens:

 

Specimen Type: Whole blood

Container/Tube:

Preferred: Lavender top (EDTA) or yellow top (ACD)

Acceptable: Any anticoagulant

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.

Specimen Stability Information: Ambient (preferred)/Refrigerated

 

Prenatal Specimens

Due to the complexity of prenatal testing, consultation with the laboratory is required for all prenatal testing.

 

Specimen Type: Amniotic fluid

Container/Tube: Amniotic fluid container

Specimen Volume: 20 mL

Specimen Stability Information: Refrigerated (preferred)/Ambient

 

Acceptable:

Specimen Type: Confluent cultured cells

Container/Tube: T-25 flask

Specimen Volume: 2 flasks

Collection Instructions: Submit confluent cultured cells from another laboratory.

Specimen Stability Information: Ambient (preferred)/Refrigerated


Specimen Minimum Volume

Blood: 1 mL
Amniotic Fluid: 10 mL

Specimen Stability Information

Specimen Type Temperature Time
Varies Varies

Reject Due To

No specimen should be rejected.

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday, Wednesday

Analytic Time

14 days

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

81331-SNRPN/UBE3A, (small nuclear ribonucleoprotein polypeptide Nand ubiquitin protein ligase E3A) (eg, Prader-Willi syndrome and/or Angelman syndrome), methylation analysis

 

Amniotic Fluid Culture/Genetic Test

 

88235-Tissue culture for amniotic fluid (if appropriate)

 

88240-Cryopreservation (if appropriate)

Maternal Cell Contamination, B

 

81265-Comparative analysis using Short Tandem Repeat (STR) markers; patient and comparative specimen (eg, pre-transplant recipient and donor germline testing, post-transplant non-hematopoietic recipient germline [eg, buccal swab or other germline tissue sample] and donor testing, twin zygosity testing or maternal cell contamination of fetal cells (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PWAS Prader Willi/Angelman Mol Analysis In Process

 

Result ID Test Result Name Result LOINC Value
52913 Result Summary 50397-9
52914 Result In Process
52915 Interpretation 69047-9
52916 Reason for Referral 42349-1
52917 Specimen 31208-2
52918 Source 31208-2
52919 Released By No LOINC Needed

Forms

1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.

2. Molecular Genetics: Congenital Inherited Diseases Patient Information (T521) in Special Instructions

3. If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/neurology-request-form.pdf)