rs1554121340

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PM5PP3

The NM_006772.3(SYNGAP1):​c.1465C>T​(p.Leu489Phe) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,868 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L489P) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

SYNGAP1
NM_006772.3 missense

Scores

7
11
1

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 4.15

Publications

0 publications found
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)
MIR5004 (HGNC:43532): (microRNA 5004) microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts (pri-miRNAs) that can be either protein-coding or non-coding. The primary transcript is cleaved by the Drosha ribonuclease III enzyme to produce an approximately 70-nt stem-loop precursor miRNA (pre-miRNA), which is further cleaved by the cytoplasmic Dicer ribonuclease to generate the mature miRNA and antisense miRNA star (miRNA*) products. The mature miRNA is incorporated into a RNA-induced silencing complex (RISC), which recognizes target mRNAs through imperfect base pairing with the miRNA and most commonly results in translational inhibition or destabilization of the target mRNA. The RefSeq represents the predicted microRNA stem-loop. [provided by RefSeq, Sep 2009]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 5 benign, 9 uncertain in NM_006772.3
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr6-33438498-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2000232.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.837

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SYNGAP1NM_006772.3 linkc.1465C>T p.Leu489Phe missense_variant Exon 9 of 19 ENST00000646630.1 NP_006763.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SYNGAP1ENST00000646630.1 linkc.1465C>T p.Leu489Phe missense_variant Exon 9 of 19 NM_006772.3 ENSP00000496007.1
SYNGAP1ENST00000644458.1 linkc.1465C>T p.Leu489Phe missense_variant Exon 9 of 19 ENSP00000495541.1
SYNGAP1ENST00000449372.7 linkc.1465C>T p.Leu489Phe missense_variant Exon 9 of 18 5 ENSP00000416519.4
SYNGAP1ENST00000418600.7 linkc.1465C>T p.Leu489Phe missense_variant Exon 9 of 19 5 ENSP00000403636.3
SYNGAP1ENST00000645250.1 linkc.1288C>T p.Leu430Phe missense_variant Exon 7 of 17 ENSP00000494861.1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461868
Hom.:
0
Cov.:
35
AF XY:
0.00000138
AC XY:
1
AN XY:
727240
show subpopulations
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:
53400
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112008
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Sep 01, 2017
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Jan 09, 2023
Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PP3, PM2_SUP, PP2 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.96
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Uncertain
0.040
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.69
D;D;.;.;.;.;.;.
Eigen
Pathogenic
0.81
Eigen_PC
Pathogenic
0.74
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.96
.;D;D;D;D;D;D;D
M_CAP
Uncertain
0.25
D
MetaRNN
Pathogenic
0.84
D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.52
D
MutationAssessor
Pathogenic
3.1
M;M;.;.;M;M;.;.
PhyloP100
4.1
PrimateAI
Uncertain
0.75
T
PROVEAN
Uncertain
-3.7
.;.;.;D;.;D;D;.
REVEL
Pathogenic
0.72
Sift
Uncertain
0.021
.;.;.;D;.;D;D;.
Sift4G
Uncertain
0.0030
.;D;.;D;D;D;D;.
Polyphen
1.0
D;D;.;D;D;D;.;.
Vest4
0.81, 0.79, 0.81
MutPred
0.76
Gain of ubiquitination at K492 (P = 0.1472);Gain of ubiquitination at K492 (P = 0.1472);Gain of ubiquitination at K492 (P = 0.1472);Gain of ubiquitination at K492 (P = 0.1472);Gain of ubiquitination at K492 (P = 0.1472);Gain of ubiquitination at K492 (P = 0.1472);.;.;
MVP
0.92
MPC
2.4
ClinPred
0.99
D
GERP RS
5.1
Varity_R
0.44
gMVP
0.75
Mutation Taster
=30/70
disease causing

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

Other links and lift over

dbSNP: rs1554121340; hg19: chr6-33406274; API