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Test ID: PMS2S
PMS2 Gene, Full Gene Analysis

NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.

Conditional

Useful For Suggests clinical disorders or settings where the test may be helpful

Establishing a diagnosis of Lynch syndrome/hereditary nonpolyposis colorectal cancer

 

Determining whether absence of PMS2 protein in tumor tissue, as demonstrated by immunohistochemistry, is associated with a germline mutation in the affected individual

 

Identification of familial PMS2 mutation to allow for predictive testing in family members

Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.

See Hereditary Nonpolyposis Colorectal Cancer Testing Algorithm in Special Instructions.

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test

Method Name A short description of the method used to perform the test

Polymerase Chain Reaction (PCR) followed by DNA Sequence Analysis and Gene Dosage Analysis by Multiplex Ligation-Dependent Probe Amplification (MLPA)

(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)

Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name

PMS2 Gene, Full Gene Analysis

Aliases Lists additional common names for a test, as an aid in searching

HNPCC
Hereditary Non-Polyposis Colorectal Cancer
Hereditary Non-Polyposis Colon Cancer
Lynch syndrome
Colon cancer gene testing
Constitutional mismatch repair deficiency
Mismatch repair

Specimen Type Describes the specimen type needed for testing

Varies

Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.

Specimen must arrive within 96 hours of collection.

 

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.

Forms:

1. Molecular Genetics-Inherited Cancer Syndromes Patient Information Sheet (Supply T519) in Special Instructions

2. 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 (Supply T576) is available in Special Instructions.

Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.

1 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

Plasma or serum

 

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.

Specimen TypeTemperatureTime
VariesAmbient (preferred)
 Frozen 
 Refrigerated 

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Lynch syndrome (also known as hereditary nonpolyposis colorectal cancer or HNPCC) is an autosomal dominant hereditary cancer syndrome associated with germline mutations in the mismatch repair genes, MLH1, MSH2, MSH6, and PMS2. Deletions within the 3-prime end of the EPCAM gene have also been associated with Lynch syndrome, as this leads to inactivation of the MSH2 promoter.  

 

Lynch syndrome is predominantly characterized by significantly increased risks for colorectal and endometrial cancer. The lifetime risk for colorectal cancer is highly variable and dependent on the gene involved. The risk for colorectal cancer associated MLH1 and MSH2 mutations (approximately 50%-80%) is generally higher than the risks associated with mutations in the other Lynch syndrome-related genes, and the lifetime risk for endometrial cancer (approximately 25%-60%) is also highly variable. Other malignancies within the tumor spectrum include gastric cancer, ovarian cancer, hepatobiliary and urinary tract carcinomas, and small bowel cancer. The lifetime risks for these cancers are <15%. Of the 4 mismatch repair genes, mutations within the PMS2 gene confer the lowest risk for any of the tumors within the Lynch syndrome spectrum.

 

Several clinical variants of Lynch syndrome have been defined. These include Turcot syndrome, Muir-Torre syndrome, and homozygous mismatch repair mutations (also called constitutional mismatch repair deficiency syndrome). Turcot syndrome and Muir-Torre syndrome are associated with increased risks for cancers within the tumor spectrum described, but also include brain and central nervous system malignancies and sebaceous carcinomas, respectively. Homozygous mismatch repair mutations, characterized by the presence of biallelic deleterious mutations within a mismatch repair gene, are associated with a different clinical phenotype defined by hematologic and brain cancers, cafe au lait macules, and childhood colon or small bowel cancer.

 

There are several strategies for evaluating individuals whose personal or family history of cancer is suggestive of Lynch syndrome. One such strategy involves testing the tumors from suspected individuals for microsatellite instability and/or immunohistochemistry for the presence or absence of defective DNA mismatch repair. Tumors that demonstrate absence of expression of PMS2 are more likely to have a germline mutation in the PMS2 gene.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Interpretation Provides information to assist in interpretation of the test results

All detected alterations will be evaluated according to American College of Medical Genetics and Genomics (ACMG) recommendations.(1) Variants will be classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Some individuals who have a diagnosis of PMS2-related Lynch syndrome may have a mutation that is not identified by this method (eg, deep intronic mutations, promoter mutations). The absence of a mutation, therefore, does not eliminate the possibility of a diagnosis of Lynch syndrome. For predictive testing of asymptomatic individuals, it is important to first document the presence of a PMS2 gene mutation in an affected family member.

 

In some cases, DNA alterations of undetermined significance may be identified.

 

We strongly recommend that asymptomatic patients undergoing predictive testing receive genetic counseling both prior to testing and after results are available.

 

Predictive testing of an asymptomatic child is not recommended.

 

Rare polymorphisms exist that could lead to false-negative or false-positive results. If results obtained do not match the clinical findings, additional testing should be considered.

 

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.

 

Test results should be interpreted in the context of clinical findings, family history, and other laboratory data. Errors in our interpretation of results may occur if information given is inaccurate or incomplete.

 

In addition to disease-related probes, the multiplex ligation-dependent probe amplification technique utilizes probes localized to other chromosomal regions as internal controls. In certain circumstances, these control probes may detect other diseases or conditions for which this test was not specifically intended. Results of the control probes are not normally reported. However, in cases where clinically relevant information is identified, the ordering physician will be informed of the result and provided with recommendations for any appropriate follow-up testing.

Clinical Reference Provides recommendations for further in-depth reading of a clinical nature

1. Richards CS, Bale S, Bellissimo DB, et al: ACMG recommendations for standards for interpretation and reporting of sequence variations: Revisions 2007. Genet Med 2008:10(4):294-300

2. Vaughn CP, Hart J, Samowitz WS, Swensen JJ: Avoidance of pseudogene interference in the detection of 3'deletions in PMS2. Hum Mutat 2011;32:1063-1071

3. Senter L, Clendenning M, Sotamaa K, et al: The clinical phenotype of Lynch syndrome due to germ-line PMS2 mutations. Gastroenterology 2008;135:419-428

4. Clendenning M, Hampel H, LaJeunesse J, et al: Long-range PCR facilitates the identification of PMS2-specific mutations. Hum Mutat 2006;27(5):490-495

5. Vasen HFA, Moslein G, Alonso A, et al: Guidelines for the clinical management of Lynch syndrome (hereditary non-polyposis cancer). J Med Genet 2007;44:353-362

6. Lynch Syndrome-GeneReviews-NCBI Bookshelf. Available from URL: http://www.ncbi.nlm.nih.gov/books/NBK1211/

Method Description Describes how the test is performed and provides a method-specific reference

DNA sequence analysis is performed to test for the presence of a mutation in all 15 exons of the PMS2 gene. Additionally, gene dosage analysis (multiplex ligation-dependent probe amplification) is used to test for the presence of large deletions and duplications in this gene. Mutation nomenclature is based on GenBank accession number, NM_000535.5.(Vaughn CP, Hart J, Samowitz WS, Swensen JJ: Avoidance of pseudogene interference in the detection of 3'deletions in PMS2. Hum Mutat 2011;32:1063-1071)

Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.

Friday; 10 am

Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.

14 days

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

20 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Whole Blood: 2 weeks (if available); Extracted DNA: 3 months

Performing Laboratory Location The location of the laboratory that performs the test

Rochester

Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.

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 Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

81317-PMS2 (postmeiotic segregation increased 2 [S. cerevisiae]) (eg, hereditary non-polyposis colorectal cancer, Lynch syndrome) gene analysis; full sequence analysis

LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.

Result IDReporting NameLOINC Code
33613Reason for Referral42349-1
33614ResultIn Process
33615InterpretationIn Process
33616Method49549-9
33617AmendmentN/A
33618Specimen31208-2
33619SourceN/A
33620Reviewed ByN/A
33621Release DateN/A