BRAF Codon 600 Mutation Detection with Reflex to MLH1 Promoter Methylation

Casandra

Casandra Test Code AR31243Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 0051750CPT Codes 81210, 81288

BRAF Codon 600 Mutation Detection with Reflex to MLH1 Promoter Methylation

Also known as: BRAF RFLX

Clinical Use

Order Test

Use

This test evaluates BRAF (NM_004333) exon 15 for hotspot single nucleotide variants (SNVs), multiple nucleotide variants (MNVs), and small insertions/deletions in tumor tissue, with clinical implications in solid tumors including colorectal cancer. If a BRAF V600E mutation is not detected, the test reflexes to MLH1 promoter methylation analysis, aiding in the differentiation between Lynch syndrome–associated and sporadic colorectal cancers and informing diagnosis, prognosis, and therapeutic decision-making ([arupconsult.com](https://www.arupconsult.com/node/23289?utm_source=openai)).

Special Instructions

Specimen must be formalin‑fixed (10% neutral buffered formalin, EDTA for decalcified only) paraffin‑embedded tissue with at least 25% tumor. Prefer transport of block or 8 unstained 5‑micron slides (Min: 5 slides). Include surgical pathology report. Multiple specimens require pathologist block selection directive or individual orders; otherwise a Block Selection Fee (test code 3002076) will apply. New York clients: send block or 10 unstained nonbaked slides plus 1 H&E‑stained slide; testing not NY approved ([ltd.aruplab.com](https://ltd.aruplab.com/Tests/Pub/3017204?utm_source=openai)).

Limitations

This test does not detect variants outside targeted genomic regions, copy number alterations, translocations, microsatellite instability, tumor mutational burden, deep intronic variants, large indels (>25 bp), or RNA variants. It cannot distinguish somatic from germline variants. Low‑DNA inputs (1–5 ng) may yield suboptimal results and are accepted only with client‑approved disclaimer. Technical limitations include pseudogenes, GC‑rich, repetitive, homologous, or low‑mappability regions, and primer‑overlaps. Variant allele frequency is not reported. Results must be interpreted in broader clinical context ([arupconsult.com](https://www.arupconsult.com/node/23289?utm_source=openai)).

Test Details

Methodology

NGS (Targeted)

Biomarkers

BRAF, MLH1

Gene

SNV/Indel • Mutation • Categorical (e.g., Positive / Negative / Indeterminate)

Result Turnaround Time

Not provided.

Specimen

Tissue (FFPE)

Volume

Not provided

Minimum Volume

Not provided

Container

Block or unstained 5‑micron slides (Min: 5 slides)

Collection Instructions

Formalin‑fixed (10% neutral buffered formalin, not decalcified unless EDTA) paraffin‑embedded tumor tissue ≥ 25% tumor burden; transport block or 8 unstained 5 µm slides (Min: 5). For NY: 10 unstained nonbaked slides + 1 H&E slide