6-33437678-G-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_006772.3(SYNGAP1):c.773G>T(p.Arg258Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,876 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R258H) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 31)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SYNGAP1
NM_006772.3 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 8.19

Publications

2 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 links:

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

SYNGAP1-AS1 links:

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.869

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006772.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
SYNGAP1	NM_006772.3	MANE Select	c.773G>T	p.Arg258Leu	missense	Exon 8 of 19	NP_006763.2	A0A1U9X8L0
SYNGAP1	NM_001130066.2		c.773G>T	p.Arg258Leu	missense	Exon 8 of 18	NP_001123538.1	B7ZCA0
SYNGAP1-AS1	NR_174954.1		n.330-197C>A		intron	N/A

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
SYNGAP1	ENST00000646630.1	MANE Select	c.773G>T	p.Arg258Leu	missense	Exon 8 of 19	ENSP00000496007.1	Q96PV0-1
SYNGAP1	ENST00000644458.1		c.773G>T	p.Arg258Leu	missense	Exon 8 of 19	ENSP00000495541.1	A0A2R8Y6T2
SYNGAP1	ENST00000449372.7	TSL:5	c.773G>T	p.Arg258Leu	missense	Exon 8 of 18	ENSP00000416519.4	B7ZCA0

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000399

AC:

AN:

250634

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.0000619

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS 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:

6.84e-7

AC:

AN:

1461876

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727240

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53402

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1112012

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.90

BayesDel_addAF

Pathogenic

0.24

BayesDel_noAF

Pathogenic

0.28

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.69

Eigen

Pathogenic

0.85

Eigen_PC

Pathogenic

0.78

FATHMM_MKL

Uncertain

0.96

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.43

MetaRNN

Pathogenic

0.87

MetaSVM

Pathogenic

0.98

MutationAssessor

Uncertain

2.8

PhyloP100

8.2

PrimateAI

Pathogenic

0.84

PROVEAN

Pathogenic

-5.9

REVEL

Pathogenic

0.91

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0040

Polyphen

1.0

Vest4

0.67

MutPred

0.52

Loss of MoRF binding (P = 0.0054)

MVP

0.93

MPC

2.5

ClinPred

0.99

GERP RS

4.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.47

gMVP

0.93

Mutation Taster

=17/83

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over