B-Catenin Mutation Analysis, Next-Generation Sequencing, Tumor

Casandra

Casandra Test Code MC27958Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID CTNBTCPT Codes 81479, 88381

B-Catenin Mutation Analysis, Next-Generation Sequencing, Tumor

Clinical Use

Use

This test is useful for distinguishing desmoid-type fibromatosis from other soft tissue tumors by assessing gene targets within the beta-catenin (CTNNB1) gene. It uses targeted next-generation sequencing to evaluate for somatic mutations. The test focuses specifically on the beta-catenin gene, which is known to be associated with desmoid-type fibromatosis. Mutations in exon 3 of the CTNNB1 gene have been identified in a significant percentage of desmoid-type fibromatosis cases and can aid in the diagnosis and prognosis of this condition.

Special Instructions

Not provided.

Limitations

The test cannot differentiate between somatic and germline alterations. It detects point mutations and small deletion-insertion mutations in the CTNNB1 gene but does not detect multi-exon deletions or duplications. Analytical sensitivity is 5% mutant allele frequency with at least 500x coverage. The test may not detect mutations present below this limit. Reliable results depend on adequate specimen collection and processing, and decalcification may cause PCR failure. DNA variants of uncertain significance may be identified, and negative results do not rule out the presence of variants below detection limits.

Test Details

New York Approved