chr6-33440721-C-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_ModerateBP6_Moderate

The NM_006772.3(SYNGAP1):​c.1677-8C>A variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,138 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: 𝑓 0.0000066 ( 0 hom., cov: 31)

Consequence

SYNGAP1
NM_006772.3 splice_region, splice_polypyrimidine_tract, intron

Scores

2
Splicing: ADA: 0.06307
2

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 0.211
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-AS1 (HGNC:53831): (SYNGAP1 antisense RNA 1)

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.37).
BP6
Variant 6-33440721-C-A is Benign according to our data. Variant chr6-33440721-C-A is described in ClinVar as [Likely_benign]. Clinvar id is 2814860.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
SYNGAP1NM_006772.3 linkuse as main transcriptc.1677-8C>A splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant ENST00000646630.1
SYNGAP1-AS1NR_174954.1 linkuse as main transcriptn.330-3240G>T intron_variant, non_coding_transcript_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
SYNGAP1ENST00000646630.1 linkuse as main transcriptc.1677-8C>A splice_region_variant, splice_polypyrimidine_tract_variant, intron_variant NM_006772.3 P1Q96PV0-1
SYNGAP1-AS1ENST00000630418.1 linkuse as main transcriptn.378-3240G>T intron_variant, non_coding_transcript_variant 5

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152138
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.000288
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.:
33
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152138
Hom.:
0
Cov.:
31
AF XY:
0.0000135
AC XY:
1
AN XY:
74316
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.000288
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00

ClinVar

Significance: Likely benign
Submissions summary: Benign:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Intellectual disability, autosomal dominant 5 Benign:1
Likely benign, criteria provided, single submitterclinical testingInvitaeNov 17, 2022- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.37
CADD
Benign
12
DANN
Benign
0.93
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
2.2

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.063
dbscSNV1_RF
Benign
0.19
SpliceAI score (max)
0.040
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs755438249; hg19: chr6-33408498; API