chr6-33443266-G-A

Position:

• chr6-33443266-G-A

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2 BP4 BS2

The NM_006772.3(SYNGAP1):​c.2714G>A​(p.Arg905His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,611,994 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: 0.0000048 (0 hom.)
• Consequence: SYNGAP1 NM_006772.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.90

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

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.3361493).
• BS2: High AC in GnomAdExome4 at 7 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SYNGAP1	NM_006772.3	c.2714G>A	p.Arg905His	missense_variant	15/19	ENST00000646630.1	NP_006763.2
SYNGAP1-AS1	NR_174954.1	n.329+3340C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SYNGAP1	ENST00000646630.1	c.2714G>A	p.Arg905His	missense_variant	15/19		NM_006772.3	ENSP00000496007	P1
SYNGAP1-AS1	ENST00000630418.1	n.377+3340C>T		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152200 Hom.: 0 Cov.: 32

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: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000480 AC: 7 AN: 1459794 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 726394

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: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152200 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74348

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 03, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.46
BayesDel_addAF	Benign	-0.063	T
BayesDel_noAF	Benign	-0.33
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Benign	0.098	T;T;.;.;.;.;.;.
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	.;D;D;D;D;D;D;D
M_CAP	Benign	0.026	D
MetaRNN	Benign	0.34	T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.2	M;M;.;.;M;M;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Benign	-0.96	.;.;.;N;.;N;N;.
REVEL	Benign	0.19
Sift	Uncertain	0.0060	.;.;.;D;.;D;D;.
Sift4G	Uncertain	0.0090	.;D;.;D;D;D;D;.
Polyphen		1.0	D;D;.;.;D;D;.;.
Vest4		0.46, 0.52, 0.54, 0.46
MutPred		0.21		Loss of MoRF binding (P = 0.0094);Loss of MoRF binding (P = 0.0094);Loss of MoRF binding (P = 0.0094);.;Loss of MoRF binding (P = 0.0094);Loss of MoRF binding (P = 0.0094);.;.;
MVP		0.51
MPC		2.5
ClinPred		0.83	D
GERP RS		3.6
Varity_R		0.10
gMVP		0.39

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: rs1198976275; hg19: chr6-33411043; COSMIC: COSV105124032; COSMIC: COSV105124032;