Genetic Information

Gene & Transcript Details

Gene
BRAF
Transcript
NM_001354609.1 MANE Select
Total Exons
Reference Sequence
NC_000007.13
Alternative Transcripts
IDStatusDetails
NM_001354609.2 Alternative 9687 nt | 227–2530
NM_001354609.1 Alternative 9702 nt | 226–2529

Variant Details

HGVS Notation
NM_001354609.1:c.741T>G
Protein Change
F247L
Location
Exon 6 (Exon 6 of )
6
5'Exon Structure3'
Functional Consequence
Loss of Function
Alternate Identifiers

Clinical & Population Data

Population Frequency

gnomAD
Global Frequency
0.0 in 100,000
Extremely Rare
ACMG Criteria Applied PM2
This variant is absent or extremely rare in population databases (PM2 criteria applies).

ClinVar

Open
Classification
Likely Pathogenic
2 publications
Publications List
PMID: 28512244

This sequence change replaces phenylalanine with leucine at codon 247 of the BRAF protein (p.Phe247Leu). The phenylalanine residue is highly conserved and there is a small physicochemical difference between phenylalanine and leucine. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individuals with clinical features consistent with a RASopathy (PMID: 28512244; Invitae). ClinVar contains an entry for this variant (Variation ID: 55793). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. For these reasons, this variant has been classified as Pathogenic.

PMID: 28512244

The c.741T>G (p.Phe247Leu) variant in BRAF has been reported in the literature as a confirmed and unconfirmed de novo occurrence in 2 patients with clinical features of a RASopathy (PM6, PS2, PS4_Supporting; GeneDx internal data; GTR Lab ID 26957; SCV000077236.10). In vitro functional studies provide some evidence that the p.Phe247Leu variant may impact protein function (PS3; PMID: 28512244). Furthermore, the variant is in a location that has been defined by the ClinGen RASopathy Expert Panel to be a mutational hotspot or domain of BRAF (PM1; PMID 29493581). This variant was absent from large population studies (PM2; gnomAD, http://gnomad.broadinstitute.org). The variant is located in the BRAF gene, which has been defined by the ClinGen RASopathy Expert Panel as a gene with a low rate of benign missense variants and pathogenic missense variants are common (PP2; PMID: 29493581). Computational prediction tools and conservation analysis suggest that the p.Phe247Leu variant may impact the protein (PP3). In summary, this variant meets criteria to be classified as pathogenic for RASopathies in an autosomal dominant manner. Rasopathy-specific ACMG/AMP criteria applied (PMID:29493581): PM6, PS2, PS3, PM1, PM2, PP2, PP3, PS4_Supporting.

Clinical Statement

"This variant has been reported in ClinVar as Likely pathogenic (1 clinical laboratories) and as Pathogenic (3 clinical laboratories) and as Pathogenic by ClinGen RASopathy Variant Curation Expert Panel expert panel."

COSMIC Somatic Evidence

Open
COSMIC ID
COSM259660
Recurrence
1 occurrences
PM1 Criteria
Not Applied
COSMIC Database Preview
COSMIC Preview
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Functional Impact & Domains

Functional Domain

Hotspot Status
Not a hotspot
Domain Summary
This variant is not located in a mutational hotspot or critical domain.
Related Variants in This Domain
No evidence of other pathogenic variants at this position in gene BRAF.

Functional Studies & Therapeutic Relevance

Functional Summary

Error in OpenAI Consolidation. OncoKB: BRAFF247LBRAFF247LSomaticNCBI Gene:673|Show additional gene information Variant OverviewBRAF, an intracellular kinase, is frequently mutated in melanoma, thyroid and lung cancers among others.The BRAF F247L mutation is likely oncogenic.Hide mutation effect description The class III BRAF F247L mutation is located in the RAS binding and kinase autoinhibitory domain of the BRAF protein (PMID: 31515458). This mutation has been found in colorectal cancers, among others (PMID: 31515458). In vitro studies have demonstrated that this mutation is activating as measured by increased downstream signaling compared to wildtype (PMID: 28512244, 29533785). A patient with metastatic colorectal cancer harboring BRAF F247L was treated with a combination therapy of FOLFIRI plus cetuximab and demonstrated a complete response with a progression-free survival of 12.6 months (PMID: 31515458). JAX-CKB: BRAF F247L lies within the phorbol-ester/DAG-type zinc finger domain of the Braf protein (UniProt.org). F247L confers a gain of function to Braf, as indicated by activation of downstream MAPK signaling and is transforming in cultured cells (PMID: 28512244, PMID: 29533785).

Database Previews
OncoKB
OncoKB Preview
JAX-CKB
JAX-CKB Preview

Click on previews to view full database entries. External databases may require institutional access.

Computational Analysis

Pathogenicity Predictions

SpliceAI
Predictor Consensus
Mixed/VUS
PP3 Applied
No
REVEL Score
0.0
Threshold: ≥0.75 = PP3 applied

SpliceAI Scores

Window: ±500bp
Effect Type Score Position
- Acceptor Loss (AL) 0.08 -19 bp
- Donor Loss (DL) 0.0 30 bp
+ Acceptor Gain (AG) 0.0 29 bp
+ Donor Gain (DG) 0.0 -119 bp
High impact (≥0.5) Medium impact (0.2-0.49) Low impact (<0.2)

VCEP Guidelines

Applied ACMG/AMP Criteria (VCEP Specific)

Filter Criteria:
PS3

PS3 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)

PM2

PM2 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)

PP5

PP5 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)

BP4

BP4 (Unknown (Pre-LLM))

From pre-LLM assessment (LLM Failed)