NM_006772.3:c.1723C>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 3P and 5B. PM1PP3BP6BS2

The NM_006772.3(SYNGAP1):​c.1723C>T​(p.Arg575Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000143 in 1,609,098 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R575H) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

SYNGAP1
NM_006772.3 missense

Scores

9
8
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:2

Conservation

PhyloP100: 1.07

Publications

1 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: Likely_benign. The variant received -2 ACMG points.

PM1
In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 8 uncertain in NM_006772.3
PP3
MetaRNN computational evidence supports a deleterious effect, 0.829
BP6
Variant 6-33440775-C-T is Benign according to our data. Variant chr6-33440775-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 537013.
BS2
High AC in GnomAdExome4 at 22 AD,Unknown gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SYNGAP1NM_006772.3 linkc.1723C>T p.Arg575Cys missense_variant Exon 11 of 19 ENST00000646630.1 NP_006763.2 Q96PV0-1A0A1U9X8L0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SYNGAP1ENST00000646630.1 linkc.1723C>T p.Arg575Cys missense_variant Exon 11 of 19 NM_006772.3 ENSP00000496007.1 Q96PV0-1
SYNGAP1ENST00000644458.1 linkc.1723C>T p.Arg575Cys missense_variant Exon 11 of 19 ENSP00000495541.1 A0A2R8Y6T2
SYNGAP1ENST00000449372.7 linkc.1723C>T p.Arg575Cys missense_variant Exon 11 of 18 5 ENSP00000416519.4 B7ZCA0
SYNGAP1ENST00000418600.7 linkc.1723C>T p.Arg575Cys missense_variant Exon 11 of 19 5 ENSP00000403636.3 Q96PV0-2
SYNGAP1ENST00000645250.1 linkc.1546C>T p.Arg516Cys missense_variant Exon 9 of 17 ENSP00000494861.1 A0A2R8YDS2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152210
Hom.:
0
Cov.:
31
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:
0.0000942
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000125
AC:
3
AN:
239748
AF XY:
0.0000154
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000299
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000483
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000151
AC:
22
AN:
1456888
Hom.:
0
Cov.:
39
AF XY:
0.0000138
AC XY:
10
AN XY:
724444
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33340
American (AMR)
AF:
0.0000227
AC:
1
AN:
44014
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26050
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39392
South Asian (SAS)
AF:
0.0000117
AC:
1
AN:
85700
European-Finnish (FIN)
AF:
0.0000190
AC:
1
AN:
52566
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
0.0000171
AC:
19
AN:
1109928
Other (OTH)
AF:
0.00
AC:
0
AN:
60138
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.477
Heterozygous variant carriers
0
2
3
5
6
8
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:
152210
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
74352
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41448
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.0000942
AC:
1
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68044
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
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
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Nov 13, 2017
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R575C variant (also known as c.1723C>T), located in coding exon 11 of the SYNGAP1 gene, results from a C to T substitution at nucleotide position 1723. The arginine at codon 575 is replaced by cysteine, an amino acid with highly dissimilar properties. This variant did not co-segregate with disease in one individual tested in our laboratory. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Intellectual disability, autosomal dominant 5 Benign:1
Sep 06, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

SYNGAP1-related disorder Benign:1
Nov 27, 2023
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.63
BayesDel_addAF
Pathogenic
0.30
D
BayesDel_noAF
Pathogenic
0.19
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.71
D;D;.;.;.;.;.;.
Eigen
Uncertain
0.50
Eigen_PC
Uncertain
0.44
FATHMM_MKL
Benign
0.71
D
LIST_S2
Pathogenic
0.99
.;D;D;D;D;D;D;D
M_CAP
Pathogenic
0.35
D
MetaRNN
Pathogenic
0.83
D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.19
D
MutationAssessor
Uncertain
2.2
M;M;.;.;M;M;.;.
PhyloP100
1.1
PrimateAI
Uncertain
0.69
T
PROVEAN
Pathogenic
-5.3
.;.;.;D;.;D;D;.
REVEL
Pathogenic
0.71
Sift
Uncertain
0.0010
.;.;.;D;.;D;D;.
Sift4G
Uncertain
0.0020
.;D;.;D;D;D;D;.
Polyphen
1.0
D;D;.;.;D;D;.;.
Vest4
0.25, 0.29, 0.28, 0.30
MutPred
0.74
Loss of MoRF binding (P = 0.038);Loss of MoRF binding (P = 0.038);Loss of MoRF binding (P = 0.038);Loss of MoRF binding (P = 0.038);Loss of MoRF binding (P = 0.038);Loss of MoRF binding (P = 0.038);.;.;
MVP
0.87
MPC
2.6
ClinPred
0.96
D
GERP RS
4.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.37
gMVP
0.87
Mutation Taster
=39/61
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs758101067; hg19: chr6-33408552; API