rs201937982

Positions:

• chr3-12609335-A-G
• chr3-12609335-A-T

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 2P and 10B. PM2 BP4_Strong BP6 BP7 BS2

The NM_002880.4(RAF1):​c.321T>C​(p.Gly107=) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000346 in 1,445,956 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000035 (0 hom.)
• Consequence: RAF1 NM_002880.4 splice_region, synonymous
• Scores: Splicing: ADA: 0.002488
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:3
• Conservation: PhyloP100: 1.05

Genes affected

RAF1 (HGNC:9829): (Raf-1 proto-oncogene, serine/threonine kinase) This gene is the cellular homolog of viral raf gene (v-raf). The encoded protein is a MAP kinase kinase kinase (MAP3K), which functions downstream of the Ras family of membrane associated GTPases to which it binds directly. Once activated, the cellular RAF1 protein can phosphorylate to activate the dual specificity protein kinases MEK1 and MEK2, which in turn phosphorylate to activate the serine/threonine specific protein kinases, ERK1 and ERK2. Activated ERKs are pleiotropic effectors of cell physiology and play an important role in the control of gene expression involved in the cell division cycle, apoptosis, cell differentiation and cell migration. Mutations in this gene are associated with Noonan syndrome 5 and LEOPARD syndrome 2. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Benign. Variant got -8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.58).
• BP6: Variant 3-12609335-A-G is Benign according to our data. Variant chr3-12609335-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 165010.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Uncertain_significance=2}.
• BP7: Synonymous conserved (PhyloP=1.05 with no splicing effect.
• BS2: High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RAF1	NM_002880.4	c.321T>C	p.Gly107=	splice_region_variant, synonymous_variant	4/17	ENST00000251849.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RAF1	ENST00000251849.9	c.321T>C	p.Gly107=	splice_region_variant, synonymous_variant	4/17	1	NM_002880.4	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251270 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135822

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000346 AC: 5 AN: 1445956 Hom.: 0 Cov.: 29 AF XY: 0.00000139 AC XY: 1 AN XY: 720374

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000895

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.11e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.00000610 Hom.: 0

Bravo AF: 0.0000416

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Sep 08, 2021	Variant summary: RAF1 c.321T>C (p.Gly107Gly) alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 8e-06 in 251270 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.321T>C in individuals affected with Noonan Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. A co-occurrence with a pathogenic variant has been reported (SOS1 c.1656G>C, p.Arg552Ser; Internal testing), providing supporting evidence for a benign role. A ClinVar submitter (evaluation after 2014) cites the variant as likely benign. Based on the evidence outlined above, the variant was classified as likely benign. -
Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Sep 02, 2010	Variant classified as Uncertain Significance - Favor Benign. The Gly107Gly varia nt has not been previously reported in the literature or been identified in our laboratory. This variant does not result in an amino acid change, but it does al ter the first base of exon 4 which could have an effect on splicing. Splicing va riants have not been reported as part of the mutation spectrum for RAF1, which a re typically gain-of-function. -

RASopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 07, 2023

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. ClinVar contains an entry for this variant (Variation ID: 165010). This variant has not been reported in the literature in individuals affected with RAF1-related conditions. This variant is present in population databases (rs201937982, gnomAD 0.006%). This sequence change affects codon 107 of the RAF1 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the RAF1 protein. It affects a nucleotide within the consensus splice site. -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Jul 30, 2018

- -

Cardiovascular phenotype Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 02, 2021

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.58
CADD	Benign	15
DANN	Benign	0.71

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0025
dbscSNV1_RF	Benign	0.032
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs201937982; hg19: chr3-12650834;