rs727504636

Positions:

• chr2-38986120-G-T

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 0P and 11B. BP4_Moderate BP6 BS1 BS2

The NM_005633.4(SOS1):​c.3706C>A​(p.Pro1236Thr) variant causes a missense change. The variant allele was found at a frequency of 0.0000204 in 1,613,778 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1236L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.00015 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: SOS1 NM_005633.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:3
• Conservation: PhyloP100: 6.97

Genes affected

SOS1 (HGNC:11187): (SOS Ras/Rac guanine nucleotide exchange factor 1) This gene encodes a protein that is a guanine nucleotide exchange factor for RAS proteins, membrane proteins that bind guanine nucleotides and participate in signal transduction pathways. GTP binding activates and GTP hydrolysis inactivates RAS proteins. The product of this gene may regulate RAS proteins by facilitating the exchange of GTP for GDP. Mutations in this gene are associated with gingival fibromatosis 1 and Noonan syndrome type 4. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Benign. Variant got -11 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.2544787).
• BP6: Variant 2-38986120-G-T is Benign according to our data. Variant chr2-38986120-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 179112.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=3, Benign=1}.
• BS1: Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.000151 (23/152076) while in subpopulation AMR AF= 0.00131 (20/15256). AF 95% confidence interval is 0.000868. There are 0 homozygotes in gnomad4. There are 5 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High AC in GnomAd4 at 23 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SOS1	NM_005633.4	c.3706C>A	p.Pro1236Thr	missense_variant	23/23	ENST00000402219.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SOS1	ENST00000402219.8	c.3706C>A	p.Pro1236Thr	missense_variant	23/23	1	NM_005633.4	A1

Frequencies

GnomAD3 genomes AF: 0.000151 AC: 23 AN: 152076 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.000959

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251168 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135708

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: 0.00

Gnomad OTH exome AF: 0.000326

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461702 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727146

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000112

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: 0.00

Gnomad4 OTH exome AF: 0.0000828

GnomAD4 genome AF: 0.000151 AC: 23 AN: 152076 Hom.: 0 Cov.: 32 AF XY: 0.0000673 AC XY: 5 AN XY: 74284

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.000959

Bravo AF: 0.000264

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 11, 2024	Variant summary: SOS1 c.3706C>A (p.Pro1236Thr) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251168 control chromosomes. 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.3706C>A in individuals affected with Noonan Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 179112). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Dec 30, 2014	p.Pro1236Thr in exon 23 of SOS1: This variant is not expected to have clinical s ignificance because it was identified in 2 probands with clinical features of No onan syndrome who inherited the variant from unaffected parents, one parent car ried the variant in an apparently homozygous state (LMM unpublished data). In ad dition, 2 unaffected siblings from one of these families also carried the varian t. This variant has also been identified in 1/67696 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org). -

Noonan syndrome 4 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

St. Jude Molecular Pathology, St. Jude Children's Research Hospital

Sep 01, 2022

The SOS1 c.3706C>A (p.Pro1236Thr) missense change has a maximum subpopulation frequency of 0.0028% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). The in silico tool REVEL is inconclusive about a pathogenic or benign effect of this variant on protein function, and to our knowledge functional studies have not been performed. To our knowledge, this variant has not been reported in individuals with Noonan syndrome. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -

RASopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 26, 2024

This sequence change replaces proline, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1236 of the SOS1 protein (p.Pro1236Thr). This variant is present in population databases (rs727504636, gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SOS1-related conditions. ClinVar contains an entry for this variant (Variation ID: 179112). 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 not expected to disrupt SOS1 protein function with a negative predictive value of 80%. 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. -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Nov 17, 2020

- -

Cardiovascular phenotype Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 10, 2020

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
AlphaMissense	Benign	0.091
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.62	D;D;T
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Benign	0.077	D
MetaRNN	Benign	0.25	T;T;T
MetaSVM	Uncertain	0.27	D
MutationAssessor	Uncertain	2.0	M;M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.76	T
PROVEAN	Benign	-1.6	N;N;N
REVEL	Uncertain	0.33
Sift	Pathogenic	0.0	D;D;D
Sift4G	Benign	0.063	T;T;T
Polyphen		1.0	D;D;.
Vest4		0.37
MutPred		0.15		Loss of catalytic residue at P1236 (P = 0.0205);Loss of catalytic residue at P1236 (P = 0.0205);.;
MVP		0.57
MPC		0.53
ClinPred		0.39	T
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.37
gMVP		0.33

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: rs727504636; hg19: chr2-39213261;