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Test ID: MYHZ MUTYH Gene, Full Gene Analysis, Varies


Shipping Instructions


Specimen preferred to arrive within 96 hours of draw.



Specimen Required


Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.

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.

Additional Information: To ensure minimum volume and concentration of DNA is met, the preferred volume of blood must be submitted. Testing may be canceled if DNA requirements are inadequate.


Forms

1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

2. Molecular Genetics: Inherited Cancer Syndromes Patient Information (T519) in Special Instructions

3. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Oncology Test Request (T729)

-Gastroenterology and Hepatology Client Test Request (T728)

Useful For

Confirmation of suspected clinical diagnosis of MUTYH-associated polyposis (MAP) in patients with adenomatous polyps or early-onset colorectal cancer

 

Identification of familial MUTYH mutations to allow for predictive or diagnostic testing in family members

Testing Algorithm

See Colonic Polyposis Syndromes Testing Algorithm in Special Instructions.

Method Name

Custom Sequence Capture/Targeted Next-Generation Sequencing followed by Polymerase Chain Reaction (PCR) and Sanger Sequencing

Reporting Name

MUTYH Full Gene Analysis

Specimen Type

Varies

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Ambient (preferred)
  Frozen 
  Refrigerated 

Clinical Information

Biallelic germline mutations in the MUTYH gene (also known as MYH) cause MUTYH-associated polyposis (MAP) syndrome, an autosomal recessive form of hereditary colorectal cancer. MAP is a polyposis syndrome typically associated with 10 to 100 adenomatous colon polyps, which in turn confer a significantly increased risk for colorectal cancer. Therefore, phenotypic overlap exists between MAP and attenuated familial adenomatous polyposis (FAP). However, the number of cumulative polyps is variable and can mimic both classic FAP, associated with hundreds to thousands of polyps, and Lynch syndrome, which is generally associated with very few (1-5) adenomatous polyps. Therefore, evaluation for MUTYH should be considered in patients with early onset colorectal cancer in whom a DNA mismatch repair (MMR) defect has not been identified.

 

Patients with biallelic MUTYH mutations are at risk for extracolonic manifestations including upper gastrointestinal polyps or cancer as well as other tumors. Congenital hyperpigmentation of the retinal epithelium (CHRPE), dental anomalies, dermal cysts, desmoid tumors, and osteomas may also occur, but to a lesser extent than what is observed in patients with FAP.

 

Literature suggests that monoallelic carriers may also be at increased risk for colon, gastric, breast, and endometrial cancer. Approximately 1% to 2% of mixed European Caucasian individuals are predicted to carry a MUTYH mutation. Therefore, the reproductive partners of monoallelic and biallelic carriers should be offered carrier screening to adequately assess the risk of their offspring to have MAP.

 

Two mutations, G396D and Y179C (originally known as G382D and Y165C), account for approximately 85% of the disease-causing MUTYH mutations in affected mixed European Caucasian individuals.

Reference Values

An interpretive report will be provided.

Interpretation

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

Clinical Reference

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. Goodenberger M, Lindor NM: Lynch syndrome and MYH-associated polyposis: review and testing strategy. J Clin Gastroenterol 2011;45(6):488-500

3. Lindor NM, McMaster ML, Lindor CJ, et al: Concise handbook of familial cancer susceptibility syndromes. Second edition. J Natl Cancer Inst Monogr 2008;(38):1-93

4. Win AK, Cleary SP, Dowty JG, et al: Cancer risks for monoallelic MUTYH mutation carriers with a family history of colorectal cancer. Int J Cancer 2011;129(9):2256-2262

5. MUTYH-Associated Polyposis-GeneReviews-NCBI Bookshelf. Available at  www.ncbi.nlm.nih.gov/books/NBK107219/

Day(s) and Time(s) Performed

Performed weekly; Varies

Analytic Time

14 days

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

81406

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MYHZ MUTYH Full Gene Analysis 94228-4

 

Result ID Test Result Name Result LOINC Value
BA1637 Result Summary 50397-9
BA1638 Result 82939-0
BA1639 Interpretation 69047-9
BA1640 Additional Information 48767-8
BA1641 Specimen 31208-2
BA1642 Source 31208-2
BA1643 Released By 18771-6
Mayo Clinic Laboratories | Gastroenterology Catalog Additional Information:

mml-gi-colon-cancer