rs750459631

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

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
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -13 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 id is 205543.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.
BS1
Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.000046 (7/152128) while in subpopulation NFE AF= 0.000103 (7/68002). AF 95% confidence interval is 0.0000477. There are 0 homozygotes in gnomad4. There are 4 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
BS2
High AC in GnomAd4 at 7 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
GABRG2NM_198904.4 linkuse as main transcriptc.549-3T>G splice_region_variant, intron_variant ENST00000639213.2 NP_944494.1 P18507-2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
GABRG2ENST00000639213.2 linkuse as main transcriptc.549-3T>G splice_region_variant, intron_variant 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
GnomAD3 exomes
AF:
0.0000359
AC:
9
AN:
250734
Hom.:
0
AF XY:
0.0000221
AC XY:
3
AN XY:
135506
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 SAS 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
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000331
Gnomad4 OTH exome
AF:
0.00
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
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000103
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000100
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
Uncertain significance, criteria provided, single submitterclinical testingGeneDxSep 09, 2016The 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. -
Likely benign, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenJun 01, 2024GABRG2: BP4 -
Childhood epilepsy with centrotemporal spikes Pathogenic:1
Pathogenic, no assertion criteria providedcase-controlBioinformatics Core, Luxembourg Center for Systems BiomedicineJan 01, 2017CAADphred>15 -
Epilepsy, childhood absence 2;C1969810:Febrile seizures, familial, 8 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJul 23, 2023In 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. 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 is not likely to affect RNA splicing. ClinVar contains an entry for this variant (Variation ID: 205543). This variant has been observed in individual(s) with Rolandic epilepsy (PMID: 25726841, 29358611). This variant is present in population databases (rs750459631, gnomAD 0.009%). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.61
CADD
Benign
16
DANN
Benign
0.76

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

LitVar

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

Other links and lift over

dbSNP: rs750459631; hg19: chr5-161528238; API