NM_006772.3:c.763-8C>T

Variant names:

• chr6-33437660-C-T
• NM_006772.3:c.763-8C>T

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_Strong BP6_Moderate BS2

The NM_006772.3(SYNGAP1):​c.763-8C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,848 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: SYNGAP1 NM_006772.3 splice_region, intron
• Scores: Splicing: ADA: 0.0001531
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 1.88
• 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: Benign. The variant received -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.72).
• BP6: Variant 6-33437660-C-T is Benign according to our data. Variant chr6-33437660-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 1593258.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS2: High AC in GnomAdExome4 at 7 AD,Unknown gene.

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.763-8C>T		splice_region intron	N/A	NP_006763.2	A0A1U9X8L0
	SYNGAP1	NM_001130066.2		c.763-8C>T		splice_region intron	N/A	NP_001123538.1	B7ZCA0
	SYNGAP1-AS1	NR_174954.1		n.330-179G>A		intron	N/A

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SYNGAP1	ENST00000646630.1	MANE Select	c.763-8C>T		splice_region intron	N/A	ENSP00000496007.1	Q96PV0-1
	SYNGAP1	ENST00000644458.1		c.763-8C>T		splice_region intron	N/A	ENSP00000495541.1	A0A2R8Y6T2
	SYNGAP1	ENST00000449372.7	TSL:5	c.763-8C>T		splice_region intron	N/A	ENSP00000416519.4	B7ZCA0

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461848 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727218

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53374

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000629 AC: 7 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 31

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	-0.72
CADD	Benign	6.6
DANN	Benign	0.80
PhyloP100		1.9

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00015
dbscSNV1_RF	Benign	0.072
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

hg19: chr6-33405437;