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CTNNB1 Mutational Analysis

CTNNB1 Mutational Analysis

Indication:  

Somatic mutations in CTNNB1 (also known as beta-catenin), primarily involving exon 3 (codons 5 and 70), have been reported in desmoids tumors, adrenal cortical carcinoma, biliary tract adenocarcinoma, medulloblastoma, endometrial adenocarcinoma, ovarian endometroid carcinoma, diffuse large B-cell lymphoma, NK-T cell lymphoma, Wilms tumor, hepatocellular carcinoma, pancreatic tumors, pituitary craniopharyngioma, salivary gland basal cell adenoma, malignant melanoma, intestinal adenocarcinoma, and, papillary and anaplastic carcinoma of thyroid.

Clinically, CTNNB1 mutations can provide evidence of an oncogenic molecular abnormality in appropriate clinicopathologic settings. The molecular diagnostics laboratory (MDL) has developed a clinical assay using PCR-based DNA sequencing (Sanger sequencing) of exon 3 of CTNNB1 to test for mutations in codons 5 to 70 in formalin-fixed paraffin-embedded tumor samples.

Methodology:  

This test is performed by PCR-based Sanger sequencing of DNA to examine the mutation status of codons 5-70 in exon 3 of CTNNB1.

Test Parameters:  

This assay will detect mutations present in exon 3 (codons 5-70) of CTNNB1. The sensitivity of the Sanger sequencing assay is 20% of variant sequence in the background of wild-type sequence.

Turnaround Time:

7-10 days

Sample Requirements:
• 10 ug of purified DNA, sent on dry ice

or

• Four to six unstained recut slides of formalin-fixed, paraffin embedded tissue containing adequate amounts of tumor to be analyzed (See Sensitivity.)
The area of tumor to be analyzed should be indicated by circling the area on the bottom side of the slide or in a separate H&E-stained guide section.
Please provide a copy of the corresponding pathology report.

CPT Codes:
81403

Additional charges may apply for tissue extraction.

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.


© 2014 The University of Texas MD Anderson Cancer Center