rs1555370121

Positions:

• chr14-50159854-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_006939.4(SOS2):​c.1429C>T​(p.Arg477Trp) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,842 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R477Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SOS2 NM_006939.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 3.90

Genes affected

SOS2 (HGNC:11188): (SOS Ras/Rho guanine nucleotide exchange factor 2) This gene encodes a regulatory protein that is involved in the positive regulation of ras proteins. Mutations in this gene are associated with Noonan Syndrome-9. [provided by RefSeq, Jul 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SOS2	NM_006939.4	c.1429C>T	p.Arg477Trp	missense_variant	10/23	ENST00000216373.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SOS2	ENST00000216373.10	c.1429C>T	p.Arg477Trp	missense_variant	10/23	1	NM_006939.4	P1
SOS2	ENST00000543680.5	c.1330C>T	p.Arg444Trp	missense_variant	9/22	1
SOS2	ENST00000555794.2	c.544C>T	p.Arg182Trp	missense_variant	4/6	1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251384 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135856

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461842 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727218

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Noonan syndrome 9 Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 15, 2021	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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SOS2 protein function. ClinVar contains an entry for this variant (Variation ID: 520415). This variant has not been reported in the literature in individuals affected with SOS2-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with tryptophan at codon 477 of the SOS2 protein (p.Arg477Trp). The arginine residue is moderately conserved and there is a moderate physicochemical difference between arginine and tryptophan. -
Uncertain significance, criteria provided, single submitter	clinical testing	Center For Human Genetics And Laboratory Diagnostics, Dr. Klein, Dr. Rost And Colleagues	Dec 22, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	-	- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Feb 08, 2021

Variant summary: SOS2 c.1429C>T (p.Arg477Trp) results in a non-conservative amino acid change located in the Pleckstrin homology domain of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251384 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.1429C>T in individuals affected with Noonan Syndrome And Related Conditions and no experimental evidence demonstrating its impact on protein function have been reported. One ClinVar submitter (evaluation after 2014) cites the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 24, 2023

The p.R477W variant (also known as c.1429C>T), located in coding exon 10 of the SOS2 gene, results from a C to T substitution at nucleotide position 1429. The arginine at codon 477 is replaced by tryptophan, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.47
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.070
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.84	D;.
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Uncertain	0.089	D
MetaRNN	Uncertain	0.70	D;D
MetaSVM	Uncertain	0.35	D
MutationAssessor	Uncertain	2.7	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.68	T
PROVEAN	Uncertain	-3.1	D;D
REVEL	Uncertain	0.58
Sift	Uncertain	0.017	D;D
Sift4G	Uncertain	0.011	D;D
Polyphen		1.0	D;.
Vest4		0.77
MutPred		0.56		Loss of disorder (P = 0.0178);.;
MVP		0.69
MPC		1.6
ClinPred		0.96	D
GERP RS		5.0
Varity_R		0.28
gMVP		0.51

Splicing

Name	Calibrated prediction	Score	Prediction
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: rs1555370121; hg19: chr14-50626572;