Test ID: MYH
MYH Gene Analysis for Multiple Adenoma, Y165C and G382D
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Determining whether the clinical phenotype of multiple colorectal adenomas is due to biallelic MYH mutations in the affected individual
Predictive testing and familial risk assessment by carrier screening for multiple colorectal adenomatous polyps when an MYH mutation has been identified in an affected family member
Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request
Tests for the Y176C and G382D mutations only.
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
See Colonic Adenomatous Polyposis Syndromes 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)
(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
Aliases Lists additional common names for a test, as an aid in searching
Familial polyposis
Multiple adenomas
MUTYH
polyps
Specimen Type Describes the specimen type needed for testing
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 draw.
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.
3. If not ordering electronically, submit a Molecular Genetics Request Form (Supply T245) with the specimen.
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.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | NA |
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 Type | Temperature | Time |
|---|---|---|
| Varies | Ambient (preferred) | |
| Frozen | ||
| Refrigerated | ||
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Biallelic germline mutations in the MYH gene (official symbol MUTYH) cause MYH-associated polyposis (MAP) syndrome, an autosomal recessive form of inherited colorectal cancer. Approximately 15% to 20% of all colorectal cancer cases are thought to be due to heritable genetic causes. The 2 most common forms of hereditary colorectal cancer are familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). FAP accounts for <1% of all colorectal cancer cases and HNPCC accounts for approximately 2% to 3% of all colorectal cancer. The proportion of inherited colorectal cancer cases attributable to MAP is not known at this time.
Phenotypic overlap exists between MAP and FAP. However, patients with MAP tend to develop fewer adenomatous polyps (generally <100) than patients with classical FAP, who generally develop hundreds to thousands of polyps. Patients with biallelic MYH mutations are at risk for colorectal cancer and other extracolonic manifestations (upper gastrointestinal tumors, congenital hyperpigmentation of the retinal epithelium) similar to those observed in patients with FAP. Although patients with MAP typically present with multiple polyps, literature suggests that biallelic mutations have been seen in patients with early onset colorectal cancer. Therefore, screening for MYH should be considered in patients with early onset colorectal cancer in whom no DNA mismatch repair (MMR) defect has been identified.
Literature suggests that monoallelic carriers may be at slightly increased risk for colon cancer, upper gastrointestinal cancer, and other tumors. Approximately 1% to 2% mixed European Caucasian individuals are predicted to carry an MYH mutation. Therefore, the reproductive partners of monoallelic and biallelic carriers should be offered carrier screening to adequately assess the risk of their offspring having MAP.
The MYH gene is located on chromosome 1 and encodes a base excision repair protein that functions to repair oxidative DNA damage. This assay provides direct analysis of the Y165C and G382D mutations in the MYH gene. These 2 mutations account for approximately 85% of the disease-causing MYH mutations in affected mixed European Caucasian individuals. Refer to Hereditary Colorectal Cancer: Adenomatous Polyposis Syndromes, Mayo Medical Laboratories Communique 2004 Sep;29(9) for more information regarding diagnostic strategy. Also see Colonic Adenomatous Polyposis Syndromes Testing Algorithm in Special Instructions.
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
An interpretive report will be provided.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This assay will not detect all of the mutations that cause MAP. Therefore, the absence of a detectable mutation(s) does not rule out the possibility that an individual is a carrier of or affected with this disease.
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.
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.
In rare cases, DNA alterations of undetermined significance may be identified.
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.
It is important to first document the presence of identifiable MYH mutation(s) in an affected family member prior to performing predictive testing.
We strongly recommend that patients undergoing predictive testing receive genetic counseling both prior to testing and after results are available.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Sieber OM, Lipton L, Crabtree M, et al: Multiple colorectal adenomas, classic adenomatous polyposis, and germ-line mutations in MYH. N Engl J Med 2003;348(9):791-799
2. Wang L, Baudhuin LM, Boardman LA, Steenblock KJ, et al: MYH mutations in patients with attenuated and classic polyposis and with young-onset colorectal cancer without polyps. Gastroenterology 2004;127(1):9-16
3. Croitoru M, Cleary S, Di Nicola N, et al: Association between biallelic and monoallelic germline MYH gene mutations and colorectal cancer risk. J Natl Cancer Inst 2004;96:1631-1634
Method Description Describes how the test is performed and provides a method-specific reference
A PCR-based assay that includes Bby I and Bgl II digestion of amplified product is used to test DNA for the presence of the Y165C and G382D mutations in the MYH gene. (Unpublished Mayo method)
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 a.m.
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.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
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.
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.
81401-MUTYH (mutY homolog [E. coli]) (eg, MYH-associated polyposis), common variants (eg, Y165C, G382D)
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 ID | Reporting Name | LOINC Code |
|---|---|---|
| 22440 | Specimen | 31208-2 |
| 22441 | Specimen ID | N/A |
| 22442 | Source | N/A |
| 22443 | Order Date | N/A |
| 22444 | Reason For Referral | 42349-1 |
| 22445 | Method | In Process |
| 22446 | Result | 40959-9 |
| 22447 | Interpretation | 69047-9 |
| 22448 | Amendment | In Process |
| 22449 | Reviewed By: | N/A |
| 22450 | Release Date | N/A |
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