6-33437724-G-A

Variant names:

• chr6-33437724-G-A
• rs1256016634
• NM_006772.3:c.819G>A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_006772.3(SYNGAP1):​c.819G>A​(p.Glu273Glu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,152 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 Likely benign (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
• Consequence: SYNGAP1 NM_006772.3 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.0270
• Publications: 0 publications found

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

Our verdict: Likely_benign. The variant received -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.7).
• BP6: Variant 6-33437724-G-A is Benign according to our data. Variant chr6-33437724-G-A is described in ClinVar as Likely_benign. ClinVar VariationId is 2128524.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-0.027 with no splicing effect.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SYNGAP1	NM_006772.3	MANE Select	c.819G>A	p.Glu273Glu	synonymous	Exon 8 of 19	NP_006763.2	A0A1U9X8L0
	SYNGAP1	NM_001130066.2		c.819G>A	p.Glu273Glu	synonymous	Exon 8 of 18	NP_001123538.1	B7ZCA0
	SYNGAP1-AS1	NR_174954.1		n.330-243C>T		intron	N/A

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SYNGAP1	ENST00000646630.1	MANE Select	c.819G>A	p.Glu273Glu	synonymous	Exon 8 of 19	ENSP00000496007.1	Q96PV0-1
	SYNGAP1	ENST00000644458.1		c.819G>A	p.Glu273Glu	synonymous	Exon 8 of 19	ENSP00000495541.1	A0A2R8Y6T2
	SYNGAP1	ENST00000449372.7	TSL:5	c.819G>A	p.Glu273Glu	synonymous	Exon 8 of 18	ENSP00000416519.4	B7ZCA0

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152152 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000241

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152152 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74330

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000241 AC: 1 AN: 41414

American (AMR) AF: 0.00 AC: 0 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5200

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	-	1	Intellectual disability, autosomal dominant 5 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	7.9
DANN	Benign	0.83
PhyloP100		-0.027

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

Other links and lift over

dbSNP: rs1256016634; hg19: chr6-33405501;