6-33420269-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2PP2BP4_Moderate

The NM_006772.3(SYNGAP1):c.5G>A(p.Ser2Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000196 in 1,532,428 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 28)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

SYNGAP1
NM_006772.3 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 1.73

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 Uncertain_significance. Variant got 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP2

Missense variant where missense usually causes diseases, SYNGAP1

BP4

Computational evidence support a benign effect (MetaRNN=0.15713295).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SYNGAP1	NM_006772.3 linkuse as main transcript	c.5G>A	p.Ser2Asn	missense_variant	1/19	ENST00000646630.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SYNGAP1	ENST00000646630.1 linkuse as main transcript	c.5G>A	p.Ser2Asn	missense_variant	1/19		NM_006772.3	P1	Q96PV0-1

Frequencies

GnomAD3 genomes

AF:

0.00000660

AC:

AN:

151532

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

GnomAD3 exomes

AF:

0.00000687

AC:

AN:

145660

Hom.:

AF XY:

0.00

AC XY:

AN XY:

78938

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000911

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000145

AC:

AN:

1380896

Hom.:

Cov.:

AF XY:

0.00000147

AC XY:

AN XY:

681404

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:

0.00000187

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000660

AC:

AN:

151532

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

73994

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

Alfa

AF:

0.0000660

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000678

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 28, 2022

The c.5G>A (p.S2N) alteration is located in exon 1 (coding exon 1) of the SYNGAP1 gene. This alteration results from a G to A substitution at nucleotide position 5, causing the serine (S) at amino acid position 2 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Intellectual disability, autosomal dominant 5

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 23, 2023

The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 2 of the SYNGAP1 protein (p.Ser2Asn). 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: 1491962). 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. 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

Benign

0.21

BayesDel_addAF

Benign

-0.46

BayesDel_noAF

Benign

-0.69

Cadd

Benign

Dann

Benign

0.95

DEOGEN2

Benign

0.046

T;T;.;.;.;.

Eigen

Benign

-0.67

Eigen_PC

Benign

-0.55

FATHMM_MKL

Benign

0.53

M_CAP

Uncertain

0.086

MetaRNN

Benign

0.16

T;T;T;T;T;T

MetaSVM

Benign

-0.95

MutationAssessor

Benign

0.0

N;N;.;.;N;N

MutationTaster

Benign

1.0

N;N;N

PrimateAI

Pathogenic

0.90

Polyphen

0.0

B;B;.;.;.;.

Vest4

0.13, 0.23, 0.22

MutPred

0.12

Loss of phosphorylation at S2 (P = 0.0013);Loss of phosphorylation at S2 (P = 0.0013);Loss of phosphorylation at S2 (P = 0.0013);Loss of phosphorylation at S2 (P = 0.0013);Loss of phosphorylation at S2 (P = 0.0013);Loss of phosphorylation at S2 (P = 0.0013);

MVP

0.043

MPC

1.3

ClinPred

0.20

GERP RS

2.8

Varity_R

0.093

gMVP

0.25

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