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HelpTest ID AXINZ AXIN2 Gene, Full Gene Analysis
Useful For
Confirmation of oligodontia-colorectal cancer syndrome in patients with clinical features
Additional Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| COLAB | Hereditary Colon Cancer CGH Array | Yes, (order FMTT) | Yes |
Testing Algorithm
When this test is ordered, comparative genomic hybridization array will always be performed at an additional charge.
See Colonic Polyposis Syndromes Testing Algorithm in Special Instructions.
Special Instructions
Method Name
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
AXIN2 Gene, Full Gene AnalysisSpecimen Type
VariesSpecimen 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: Specimen preferred to arrive within 96 hours of draw.
Forms:
1. Molecular Genetics: Inherited Cancer Syndromes Patient Information (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 (T576) is available in Special Instructions.
Specimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Ambient (preferred) | |
| Frozen | ||
| Refrigerated | ||
Clinical Information
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
An interpretive report will be provided.
Cautions
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.
Day(s) Performed
Performed weekly, Varies
Report Available
14 daysPerforming 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
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)