Genetic Variant SYNGAP1:p.Pro1320Thr (chr6-33451832-C-A) – ACMG Classification: Uncertain_significance (0 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_006772.3(SYNGAP1):c.3958C>A(p.Pro1320Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000711 in 1,406,658 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1320S) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 31)

Exomes 𝑓: 7.1e-7 ( 0 hom. )

Consequence

SYNGAP1
NM_006772.3 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 3.39

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 links:

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

SYNGAP1-AS1 links:

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.21594468).

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

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
SYNGAP1	NM_006772.3	MANE Select	c.3958C>A	p.Pro1320Thr	missense	Exon 19 of 19	NP_006763.2
SYNGAP1	NM_001130066.2		c.*30C>A		3_prime_UTR	Exon 18 of 18	NP_001123538.1
SYNGAP1-AS1	NR_174954.1		n.136+2438G>T		intron	N/A

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
SYNGAP1	ENST00000646630.1	MANE Select	c.3958C>A	p.Pro1320Thr	missense	Exon 19 of 19	ENSP00000496007.1
SYNGAP1	ENST00000644458.1		c.*30C>A		3_prime_UTR	Exon 19 of 19	ENSP00000495541.1
SYNGAP1	ENST00000449372.7	TSL:5	c.*30C>A		3_prime_UTR	Exon 18 of 18	ENSP00000416519.4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

7.11e-7

AC:

AN:

1406658

Hom.:

Cov.:

AF XY:

0.00000144

AC XY:

AN XY:

696060

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32128

American (AMR)

AF:

0.00

AC:

AN:

38462

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25314

East Asian (EAS)

AF:

0.00

AC:

AN:

37002

South Asian (SAS)

AF:

0.00

AC:

AN:

80426

European-Finnish (FIN)

AF:

0.00

AC:

AN:

48910

Middle Eastern (MID)

AF:

0.00

AC:

AN:

4968

European-Non Finnish (NFE)

AF:

9.25e-7

AC:

AN:

1081272

Other (OTH)

AF:

0.00

AC:

AN:

58176

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.076

BayesDel_addAF

Benign

-0.13

BayesDel_noAF

Benign

-0.42

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.058

Eigen

Uncertain

0.19

Eigen_PC

Benign

0.17

FATHMM_MKL

Uncertain

0.85

LIST_S2

Benign

0.80

M_CAP

Benign

0.016

MetaRNN

Benign

0.22

MetaSVM

Benign

-1.0

MutationAssessor

Benign

0.0

PhyloP100

3.4

PrimateAI

Uncertain

0.78

PROVEAN

Benign

-0.73

REVEL

Benign

0.091

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.047

Polyphen

0.99

Vest4

0.27

MutPred

0.36

Gain of phosphorylation at P1320 (P = 0.0127)

MVP

0.043

ClinPred

0.65

GERP RS

3.0

Varity_R

0.14

gMVP

0.48

Mutation Taster

=43/57

disease causing

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over