rs750459631

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2

The NM_198904.4(GABRG2):​c.549-3T>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000271 in 1,586,276 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

GABRG2
NM_198904.4 splice_region, intron

Scores

2
Splicing: ADA: 0.9950
1
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2B:1

Conservation

PhyloP100: 0.0180

Publications

2 publications found
Variant links:
Genes affected
GABRG2 (HGNC:4087): (gamma-aminobutyric acid type A receptor subunit gamma2) This gene encodes a gamma-aminobutyric acid (GABA) receptor. GABA is the major inhibitory neurotransmitter in the mammlian brain, where it acts at GABA-A receptors, which are ligand-gated chloride channels. GABA-A receptors are pentameric, consisting of proteins from several subunit classes: alpha, beta, gamma, delta and rho. Mutations in this gene have been associated with epilepsy and febrile seizures. Multiple transcript variants encoding different isoforms have been identified for this gene. [provided by RefSeq, Jul 2008]
GABRG2 Gene-Disease associations (from GenCC):
  • epilepsy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • developmental and epileptic encephalopathy, 74
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • febrile seizures, familial, 8
    Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
  • Dravet syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • generalized epilepsy with febrile seizures plus
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • self-limited epilepsy with centrotemporal spikes
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • undetermined early-onset epileptic encephalopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -9 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.61).
BP6
Variant 5-162101232-T-G is Benign according to our data. Variant chr5-162101232-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 205543.
BS2
High AC in GnomAd4 at 7 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GABRG2NM_198904.4 linkc.549-3T>G splice_region_variant, intron_variant Intron 4 of 9 ENST00000639213.2 NP_944494.1 P18507-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GABRG2ENST00000639213.2 linkc.549-3T>G splice_region_variant, intron_variant Intron 4 of 9 1 NM_198904.4 ENSP00000491909.2 P18507-2

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152128
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.000103
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000359
AC:
9
AN:
250734
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000794
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000251
AC:
36
AN:
1434148
Hom.:
0
Cov.:
27
AF XY:
0.0000280
AC XY:
20
AN XY:
715534
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32594
American (AMR)
AF:
0.00
AC:
0
AN:
44652
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25936
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39380
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85724
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53296
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5716
European-Non Finnish (NFE)
AF:
0.0000331
AC:
36
AN:
1087500
Other (OTH)
AF:
0.00
AC:
0
AN:
59350
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.426
Heterozygous variant carriers
0
2
4
7
9
11
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
AF:
0.0000460
AC:
7
AN:
152128
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
AN XY:
74314
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000103
AC:
7
AN:
68002
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000309
Hom.:
0
Bravo
AF:
0.0000302
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Jun 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

GABRG2: BP4 -

Sep 09, 2016
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.549-3 T>G variant in the GABRG2 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. Several in-silico splice prediction models predict that c.549-3 T>G damages the natural acceptor site of intron 4 and leads to abnormal gene splicing. However, in the absence of RNA/functional studies, the actual effect of this sequence change in this individual is unknown. The c.549-3 T>G variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). We interpret c.549-3 T>G as a variant of uncertain significance. -

Self-limited epilepsy with centrotemporal spikes Pathogenic:1
Jan 01, 2017
Bioinformatics Core, Luxembourg Center for Systems Biomedicine
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:case-control

CAADphred>15 -

EPILEPSY, CHILDHOOD ABSENCE, SUSCEPTIBILITY TO, 2;C1969810:Febrile seizures, familial, 8 Uncertain:1
Oct 30, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 4 of the GABRG2 gene. It does not directly change the encoded amino acid sequence of the GABRG2 protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs750459631, gnomAD 0.009%). This variant has been observed in individual(s) with Rolandic epilepsy (PMID: 25726841, 29358611). ClinVar contains an entry for this variant (Variation ID: 205543). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.61
CADD
Benign
16
DANN
Benign
0.76
PhyloP100
0.018
Mutation Taster
=2/98
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Benign
0.67
SpliceAI score (max)
0.060
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: rs750459631; hg19: chr5-161528238; API