Braf - Melanoma

Gene Symbol: BRAF                            

Chromosomal Locus: 7q34

 

Protein: v-raf Murine Sarcoma Virus Oncogene Homolog B1      

 

TURNAROUND TIME: 8 days.

 

TESTING METHODOLOGY:  Polymerase chain reaction (PCR) and Shifted Termination Assay for detection of specific mutations.  Mutations detected are V600E (GTGGCG), and V600G (GTG>GGG).

 

 

Collect:  FFPE tumor specimen containing at least 30% tumor mass. 5 to 6 unsustained slides with 3-4 um thick tissue sections.  Must be accompanied by a pathology report and an H&E slide with the tumor regions identified.

A Molecular Genetics Laboratory Test Requisition must accompany the specimen. Contact the Molecular Laboratory at 918-502-1721 to obtain further information.

 

Note: Counseling and informed consent are recommended for genetic testing. A consent form is available as a resource but not required.

 

 

Incidence:  Found in 40-80% of all malignant melanomas.

 

Disease Characteristics: In 2011, Zelboraf (BRAF kinase inhibitor) was FDA approved for inoperable or metastatic melanoma with a BRAF V600E mutation. These tumors have an 80% response rate to this drug.

 

Molecular Genetic Mechanism:  The BRAF V600E mutation enhances the proliferation and metastasis of tumor cells.

 

Clinical Sensitivity: The tissue sample submitted for testing must contain at least 30% tumor. The assay will detect as low as a 5% population of mutant cells.

 

Analytical Sensitvitity:  95%

 

Test Limitations: Mutations not listed in the methodology will not be detected. This test is only for somatic BRAF changes in cancer tissues. Rare diagnostic errors can occur due to primer / probe site mutations or rare polymorphisms.

 

OMIM: www.omim.org/entry/164757