6-33423572-C-A

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 1P and 6B. PP2BP4_ModerateBS2

The NM_006772.3(SYNGAP1):c.163C>A(p.Gln55Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000149 in 1,614,044 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

SYNGAP1
NM_006772.3 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 4.53

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

PP2

Missense variant in the SYNGAP1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 56 curated pathogenic missense variants (we use a threshold of 10). The gene has 112 curated benign missense variants. Gene score misZ: 5.6047 (above the threshold of 3.09). Trascript score misZ: 7.6762 (above the threshold of 3.09). GenCC associations: The gene is linked to autosomal dominant non-syndromic intellectual disability, complex neurodevelopmental disorder, intellectual disability, autosomal dominant 5, SYNGAP1-related developmental and epileptic encephalopathy, myoclonic-astatic epilepsy.

BP4

Computational evidence support a benign effect (MetaRNN=0.24966493).

BS2

High AC in GnomAdExome4 at 23 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SYNGAP1	NM_006772.3 link	c.163C>A	p.Gln55Lys	missense_variant	Exon 2 of 19	ENST00000646630.1	NP_006763.2	Q96PV0-1A0A1U9X8L0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
SYNGAP1	ENST00000646630.1 link	c.163C>A	p.Gln55Lys	missense_variant	Exon 2 of 19		NM_006772.3	ENSP00000496007.1	Q96PV0-1
SYNGAP1	ENST00000644458.1 link	c.163C>A	p.Gln55Lys	missense_variant	Exon 2 of 19			ENSP00000495541.1	A0A2R8Y6T2
SYNGAP1	ENST00000449372.7 link	c.163C>A	p.Gln55Lys	missense_variant	Exon 2 of 18	5		ENSP00000416519.4	B7ZCA0
SYNGAP1	ENST00000418600.7 link	c.163C>A	p.Gln55Lys	missense_variant	Exon 2 of 19	5		ENSP00000403636.3	Q96PV0-2

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152180

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:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.0000157

AC:

AN:

1461864

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

AN XY:

727230

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

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:

0.0000198

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74362

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:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000259

AC:

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 28, 2015

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Intellectual disability, autosomal dominant 5

Uncertain:1

Feb 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamine, which is neutral and polar, with lysine, which is basic and polar, at codon 55 of the SYNGAP1 protein (p.Gln55Lys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SYNGAP1-related conditions. ClinVar contains an entry for this variant (Variation ID: 520688). 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 SYNGAP1 protein function with a negative 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

0.61

BayesDel_addAF

Benign

-0.11

BayesDel_noAF

Benign

-0.40

CADD

Uncertain

DANN

Uncertain

0.99

DEOGEN2

Benign

0.082

T;T;.;.;.;.

Eigen

Benign

0.17

Eigen_PC

Uncertain

0.23

FATHMM_MKL

Uncertain

0.91

LIST_S2

Uncertain

0.91

.;D;D;D;D;D

M_CAP

Benign

0.012

MetaRNN

Benign

0.25

T;T;T;T;T;T

MetaSVM

Benign

-1.1

MutationAssessor

Benign

2.0

M;M;.;.;M;M

PrimateAI

Uncertain

0.79

PROVEAN

Benign

-1.2

.;.;.;N;.;N

REVEL

Benign

0.085

Sift

Uncertain

0.022

.;.;.;D;.;D

Sift4G

Uncertain

0.032

.;D;.;D;D;D

Polyphen

0.14

B;B;.;P;B;.

Vest4

0.53, 0.57, 0.51

MutPred

0.48

Gain of methylation at Q55 (P = 0.0189);Gain of methylation at Q55 (P = 0.0189);Gain of methylation at Q55 (P = 0.0189);Gain of methylation at Q55 (P = 0.0189);Gain of methylation at Q55 (P = 0.0189);Gain of methylation at Q55 (P = 0.0189);

MVP

0.19

MPC

1.6

ClinPred

0.80

GERP RS

3.7

Varity_R

0.19

gMVP

0.94

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

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