AXIN2 Gene, Full Gene Analysis
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Confirmation of oligodontia-colorectal cancer syndrome in patients with clinical features
Additional Tests Lists test(s) that are always performed, at an additional charge, with the initial test(s)
|Test ID||Reporting Name||Available Separately||Always Performed|
|COLDB||Hereditary Colon Cancer CGH Array||Yes, (order SDEL or HCCD)||Yes|
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
When this test is ordered, COLDB/61889 Hereditary Colon Cancer CGH Array will always be performed at an additional charge.
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
Polymerase Chain Reaction (PCR) Amplification/DNA Sequencing
(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)
Array comparative genomic hybridization (aCGH) is used to test for the presence of large deletions and duplications.
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
AXIN2 Gene, Full Gene Analysis
Hereditary colorectal cancer
Oligo dontia-colorectal cancer syndrome
Hereditary colorectal cancer
Oligo dontia-colorectal cancer syndrome
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.
Preferred: Lavender top (EDTA) or yellow top (ACD)
Acceptable: Any anticoagulant
Specimen Volume: 3 mL
1. Invert several times to mix blood.
2. Send specimen in original tube.
1. Molecular Genetics-Colon Cancer Patient Information Sheet (Supply T521) 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.
Note: No specimen should be rejected. If specimen is received in wrong anticoagulant or at an inappropriate temperature, include note to laboratory. If questions, contact laboratory.
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Oligodontia, defined as the congenital absence of 6 or more permanent teeth, can occur as either an isolated finding or as part of an underlying syndrome. AXIN2 is one of several genes that have been associated with nonsyndromic oligodontia. In a subset of patients, mutations in the AXIN2 gene have been found to be associated with a combined oligodontia-colorectal cancer syndrome. Oligodontia-colorectal cancer syndrome is a rare hereditary cancer syndrome. One study of a Finnish family with AXIN2-related oligodontia-colorectal cancer syndrome identified colorectal cancer in 67% (6 of 9) of family members with oligodontia and a confirmed AXIN2 mutation. The AXIN2 mutation in this family was inherited in an autosomal dominant fashion. In the same study, a de novo AXIN2 mutation was identified in a 13-year-old patient with oligodontia but no history of colorectal cancer.
Somatic AXIN2 mutations have been identified in mismatch repair-deficient colorectal tumors and have been shown to cause accumulation of beta-catenin and subsequent activation of T-cell factor-dependent transcription. These findings support the role of AXIN2 in tumorigenesis.
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.
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
This test should be ordered only for individuals with symptoms suggestive of oligodontia-colorectal cancer syndrome. Asymptomatic patients with a family history of oligodontia-colorectal cancer syndrome should not be tested until a mutation has been identified in an affected family member.
Some individuals who are carriers or have a diagnosis of oligodontia-colorectal cancer syndrome may have a mutation that is not identified by this method (eg, promoter mutations). The absence of a mutation, therefore, does not eliminate the possibility of positive carrier status or the diagnosis of oligodontia-colorectal cancer syndrome. For carrier testing, it is important to first document the presence of an AXIN2 gene mutation in an affected family member.
We strongly recommend that patients undergoing predictive testing receive genetic counseling both prior to testing and after results are available.
In some cases, DNA alterations of undetermined significance may be identified.
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.
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 of interpretation and reporting of sequence variations: revisions 2007. Genet Med 2008:10(4):294-300
2. Lammi L, Arte S, Somer M, et al: Mutations in AXIN2 Cause Familial Tooth Agenesis and Predispose to Colorectal Cancer. Am J Hum Genet 2004;74:1043-1050
3. Liu W, Dong X, Mai M, et al: Mutations in AXIN2 cause colorectal cancer with defective mismatch repair by activating beta–catenin/TCF signaling. Nat Genet 2000;26:146-147
4. Mai M, Qian C, Yokomizo A, et al: Cloning of the human homolog of conductin (AXIN2), a gene mapping to chromosome 17q23-q24. Genomics 1998;55:341-344
5. Dong X, Seelan RS, Qian C, et al: Genomic structure, chromosome mapping and expression analysis of the human AXIN2 gene. Cytogenet Cell Genet 2001;93:26-28
Method Description Describes how the test is performed and provides a method-specific reference
Bi-directional sequence analysis is used to test for the presence of a mutation in all coding regions and intron/exon boundaries of the AXIN2 gene. (Unpublished Mayo method) Array comparative genomic hybridization (aCGH) is used to test for the presence of large deletions and duplications. Swaroop A, Lewis R, Bonaga T, et al: Exon-level array CGH in a large clinical cohort demonstrates increased sensitivity of diagnostic testing for Mendelian disorders. Genet Med 2012;14:594-603)
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.
Wednesday; 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
Whole Blood: 2 weeks (if available) Extracted DNA: 3 months
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.
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.
81479-Unlisted molecular pathology code
Hereditary Colon Cancer CGH Array
81228-Cytogenomic constitutional (genome-wide) microarray analysis; interrogation of genomic regions for copy number variants (eg, bacterial artificial chromosome [BAC] or oligo-based comparative genomic hybridization [CGH] microarray 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 ID||Reporting Name||LOINC Code|
|33932||Reason for Referral||42349-1|
|33936||Array Billed?||In Process|