Reference Interval:
| Available Separately
| Components
| Reference Interval
| | No
| MLH1 Sequencing
| By report
| | No
| MLHI Deletion/Duplication
| By report
|
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| Interpretive Data: |
Background Information for HNPCC/Lynch Syndrome (MLH1) Sequencing and Deletion/Duplication:
Characteristics: Increased risk of colorectal and extra-colonic cancers including endometrial, renal pelvis, ureter, ovary, stomach, small intestine, and hepatobiliary tract.
Incidence: 1-2 percent of colorectal cancer is due to mismatch repair gene mutations.
Inheritance: Autosomal dominant
Penetrance of MLH1 Mutations: 80 percent lifetime risk of colorectal cancer; 20-60 percent risk for endometrial cancer.
Cause: Pathogenic germline MLH1, MSH2, MSH6, and PMS2 gene mutations.
Gene Tested: MLH1
Clinical Sensitivity: Approximately 45 percent of Lynch syndrome is due to MLH1 mutations.
Methodology: Bidirectional sequencing of MLH1 coding regions and intron-exon boundaries; multiplex ligation-dependent probe amplification (MLPA) to detect large MLH1 exonic deletions.Analytical Sensitivity & Specificity: 99 percent.
Limitations: Rare diagnostic errors can occur due to primer and probe site mutations.The breakpoints of large deletions/duplications will not be determined. Regulatory region mutations, deep intronic mutations and mutations in genes other than MLH1 will not be detected.
This test is performed pursuant to an agreement with Roche Molecular Systems, Inc.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.
Refer to Statement C under Testing Information at http://www.aruplab.com.
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| CPT Code(s): |
Sequencing portion: 83891 Isolation; 83898 x20 Amplification; 83904 x20 Sequencing; 83909 x2 Capillary electrophoresis; Del: 83896 Nucleic Acid Probes; 83898 Amplification; 83914 Extension; 83909 Capillary Electrophoresis; 83912 Interpretation and report - Additional CPT code modifiers may be required for procedures performed to test for oncologic or inherited disorders.
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Cross References: |
Lynch Syndrome (HNPCC/Lynch Syndrome (MLH1) Sequencing and Deletion/Duplication)
, MLH1 Full Gene Analysis (HNPCC/Lynch Syndrome (MLH1) Sequencing and Deletion/Duplication)
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