rs1554122465

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_006772.3(SYNGAP1):​c.3457C>T​(p.Arg1153Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,614,030 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SYNGAP1
NM_006772.3 missense

Scores

5
7
6

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 2.25

Publications

0 publications found
Variant links:
Genes affected
SYNGAP1 (HGNC:11497): (synaptic Ras GTPase activating protein 1) This gene encodes a Ras GTPase activating protein that is a member of the N-methyl-D-aspartate receptor complex. The N-terminal domain of the protein contains a Ras-GAP domain, a pleckstrin homology domain, and a C2 domain that may be involved in binding of calcium and phospholipids. The C-terminal domain consists of a ten histidine repeat region, serine and tyrosine phosphorylation sites, and a T/SXV motif required for postsynaptic scaffold protein interaction. The encoded protein negatively regulates Ras, Rap and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor trafficking to the postsynaptic membrane to regulate synaptic plasticity and neuronal homeostasis. Allelic variants of this gene are associated with intellectual disability and autism spectrum disorder. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2016]
SYNGAP1-AS1 (HGNC:53831): (SYNGAP1 antisense RNA 1)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SYNGAP1NM_006772.3 linkc.3457C>T p.Arg1153Trp missense_variant Exon 16 of 19 ENST00000646630.1 NP_006763.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SYNGAP1ENST00000646630.1 linkc.3457C>T p.Arg1153Trp missense_variant Exon 16 of 19 NM_006772.3 ENSP00000496007.1
SYNGAP1ENST00000644458.1 linkc.3457C>T p.Arg1153Trp missense_variant Exon 16 of 19 ENSP00000495541.1
SYNGAP1ENST00000449372.7 linkc.3415C>T p.Arg1139Trp missense_variant Exon 15 of 18 5 ENSP00000416519.4
SYNGAP1ENST00000418600.7 linkc.3457C>T p.Arg1153Trp missense_variant Exon 16 of 19 5 ENSP00000403636.3
SYNGAP1ENST00000645250.1 linkc.3280C>T p.Arg1094Trp missense_variant Exon 14 of 17 ENSP00000494861.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461838
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727228
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33470
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5734
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112010
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74352
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41444
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
May 09, 2016
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Intellectual disability, autosomal dominant 5 Uncertain:1
Apr 13, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 1153 of the SYNGAP1 protein (p.Arg1153Trp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of SYNGAP1-related disorders and/or developmental and epileptic encephalopathy (PMID: 28191889; Invitae). ClinVar contains an entry for this variant (Variation ID: 521099). 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 SYNGAP1 protein function with a positive predictive value of 95%. 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.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Uncertain
0.12
D
BayesDel_noAF
Uncertain
-0.070
CADD
Pathogenic
31
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.35
T;T;.;.;.;.;.;.
Eigen
Uncertain
0.66
Eigen_PC
Uncertain
0.61
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Benign
0.0
.;D;D;D;D;D;D;D
M_CAP
Benign
0.025
D
MetaRNN
Uncertain
0.65
D;D;D;D;D;D;D;D
MetaSVM
Benign
-0.90
T
MutationAssessor
Uncertain
2.5
M;M;.;.;M;M;.;.
PhyloP100
2.2
PrimateAI
Pathogenic
0.88
D
PROVEAN
Benign
0.0
.;.;.;D;.;D;D;.
REVEL
Benign
0.0
Sift
Pathogenic
0.0
.;.;.;D;.;D;D;.
Sift4G
Pathogenic
0.0
.;D;.;D;D;D;D;.
Vest4
0.0
ClinPred
1.0
D
GERP RS
4.6
RBP_binding_hub_radar
0.97
RBP_regulation_power_radar
2.7
Varity_R
0.57
gMVP
0.92
Mutation Taster
=66/34
polymorphism

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: rs1554122465; hg19: chr6-33412269; COSMIC: COSV53384949; COSMIC: COSV53384949; API