6-33440775-C-T

Position:

chr6-33440775-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 4P and 5B. PM1PP2PP3BP6BS2

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

Clinical Significance

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

Conservation

PhyloP100: 1.07

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 links:

SYNGAP1-AS1 (HGNC:53831): (SYNGAP1 antisense RNA 1)

SYNGAP1-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 6 uncertain in NM_006772.3

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SYNGAP1. . Gene score misZ 5.6047 (greater than the threshold 3.09). Trascript score misZ 7.6762 (greater than threshold 3.09). GenCC has associacion of gene with autosomal dominant non-syndromic intellectual disability, complex neurodevelopmental disorder, intellectual disability, autosomal dominant 5, SYNGAP1-related developmental and epileptic encephalopathy, myoclonic-astatic epilepsy.

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 id is 537013.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

BS2

High AC in GnomAdExome4 at 22 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SYNGAP1	NM_006772.3 linkuse as main transcript	c.1723C>T	p.Arg575Cys	missense_variant	11/19	ENST00000646630.1
SYNGAP1-AS1	NR_174954.1 linkuse as main transcript	n.330-3294G>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SYNGAP1	ENST00000646630.1 linkuse as main transcript	c.1723C>T	p.Arg575Cys	missense_variant	11/19		NM_006772.3	P1	Q96PV0-1
SYNGAP1-AS1	ENST00000630418.1 linkuse as main transcript	n.378-3294G>A		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152210

Hom.:

Cov.:

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

GnomAD3 exomes

AF:

0.0000125

AC:

AN:

239748

Hom.:

AF XY:

0.0000154

AC XY:

AN XY:

130188

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 SAS exome

AF:

0.0000335

Gnomad FIN exome

AF:

0.0000483

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000151

AC:

AN:

1456888

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

724444

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000227

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000117

Gnomad4 FIN exome

AF:

0.0000190

Gnomad4 NFE exome

AF:

0.0000171

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74352

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.0000942

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ExAC

AF:

0.00000824

AC:

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 13, 2017

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

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Sep 06, 2023

- -

SYNGAP1-related disorder

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Nov 27, 2023

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

BayesDel_noAF

Pathogenic

0.19

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.71

D;D;.;.;.;.;.;.

Eigen

Uncertain

0.50

Eigen_PC

Uncertain

0.44

FATHMM_MKL

Benign

0.71

LIST_S2

Pathogenic

0.99

.;D;D;D;D;D;D;D

M_CAP

Pathogenic

0.35

MetaRNN

Pathogenic

0.83

D;D;D;D;D;D;D;D

MetaSVM

Uncertain

0.19

MutationAssessor

Uncertain

2.2

M;M;.;.;M;M;.;.

MutationTaster

Benign

1.0

D;D;D;D

PrimateAI

Uncertain

0.69

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

GERP RS

4.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.37

gMVP

0.87

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over