rs1166557922

chr6-33435558-C-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 2P and 8B. PP2 PP3 BP6_Very_Strong

The NM_006772.3(SYNGAP1):c.707C>T(p.Ala236Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,880 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 Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. A236A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: SYNGAP1 NM_006772.3 missense
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: 7.91

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]

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• PP2: Missense variant where missense usually causes diseases, SYNGAP1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.822
• BP6: Variant 6-33435558-C-T is Benign according to our data. Variant chr6-33435558-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 469162.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SYNGAP1	NM_006772.3	c.707C>T	p.Ala236Val	missense_variant	7/19	ENST00000646630.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SYNGAP1	ENST00000646630.1	c.707C>T	p.Ala236Val	missense_variant	7/19		NM_006772.3	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251448 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135910

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461880 Hom.: 0 Cov.: 34 AF XY: 0.00000550 AC XY: 4 AN XY: 727240

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

Bravo AF: 0.00000378

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Intellectual disability, autosomal dominant 5 Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Apr 07, 2017

- -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Feb 25, 2021

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
Cadd	Pathogenic	28
Dann	Pathogenic	1.0
DEOGEN2	Uncertain	0.60	D;D;.;.;.;.;.;.
Eigen	Pathogenic	0.68
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Pathogenic	0.46	D
MetaRNN	Pathogenic	0.82	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.82	D
MutationAssessor	Uncertain	2.7	M;M;.;.;M;M;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.85	D
Polyphen		0.98	D;D;.;D;D;.;.;.
Vest4		0.58, 0.57, 0.53, 0.52
MutPred		0.37		Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);Loss of helix (P = 0.0558);.;.;
MVP		0.82
MPC		1.4
ClinPred		0.92	D
GERP RS		4.6
Varity_R		0.27
gMVP		0.83

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

Other links and lift over

dbSNP: rs1166557922; hg19: chr6-33403335; COSMIC: COSV53378665; COSMIC: COSV53378665;