NM_005633.4:c.1433C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PM5

The NM_005633.4(SOS1):​c.1433C>T​(p.Pro478Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,638 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. P478R) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SOS1
NM_005633.4 missense

Scores

4
7
8

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.22

Publications

1 publications found
Variant links:
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]
SOS1 Gene-Disease associations (from GenCC):
  • Noonan syndrome
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
  • Noonan syndrome 4
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae)
  • fibromatosis, gingival, 1
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • hereditary gingival fibromatosis
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • cardiofaciocutaneous syndrome
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
  • Costello syndrome
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain in NM_005633.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr2-39022995-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 636445.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SOS1NM_005633.4 linkc.1433C>T p.Pro478Leu missense_variant Exon 10 of 23 ENST00000402219.8 NP_005624.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SOS1ENST00000402219.8 linkc.1433C>T p.Pro478Leu missense_variant Exon 10 of 23 1 NM_005633.4 ENSP00000384675.2

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461638
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
727114
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86244
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53342
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111888
Other (OTH)
AF:
0.00
AC:
0
AN:
60386
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.225
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Oct 27, 2016
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Pro478Leu variant in SOS1 has been reported in 2 individuals with clinical features of Noonan syndrome, one of whom also carried an additional SOS1 varian t (p.Gln477His) in cis and both variants were de novo (Zenker 2007, Lepri 2011). This variant was absent from large population studies. An additional amino acid change at this position (p.Pro478Arg) has been reported to occur de novo in two probands, suggesting that a change at this position may not be tolerated (Zenke r 2007, Lepri 2011). Computational prediction tools and conservation analysis do not provide strong support for or against an impact to the protein. In summary, while there is some suspicion for a pathogenic role, the clinical significance of the p.Pro478Leu variant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.14
BayesDel_addAF
Pathogenic
0.35
D
BayesDel_noAF
Pathogenic
0.26
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.57
D;D;T
Eigen
Uncertain
0.32
Eigen_PC
Uncertain
0.47
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
.;D;D
M_CAP
Benign
0.047
D
MetaRNN
Uncertain
0.70
D;D;D
MetaSVM
Benign
-0.54
T
MutationAssessor
Benign
0.90
L;L;.
PhyloP100
9.2
PrimateAI
Pathogenic
0.81
D
PROVEAN
Benign
-0.42
N;N;N
REVEL
Uncertain
0.44
Sift
Benign
0.051
T;T;T
Sift4G
Benign
0.21
T;T;T
Polyphen
0.81
P;P;.
Vest4
0.90
MutPred
0.43
Loss of disorder (P = 0.0389);Loss of disorder (P = 0.0389);Loss of disorder (P = 0.0389);
MVP
0.96
MPC
0.92
ClinPred
0.58
D
GERP RS
5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.28
gMVP
0.39
Mutation Taster
=32/68
disease causing

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

Other links and lift over

dbSNP: rs1553356111; hg19: chr2-39250136; COSMIC: COSV101217220; COSMIC: COSV101217220; API