NM_198904.4:c.691G>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_198904.4(GABRG2):​c.691G>T​(p.Asp231Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. D231N) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

GABRG2
NM_198904.4 missense

Scores

11
7
1

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.08

Publications

0 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: Uncertain_significance. The variant received 4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.869

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GABRG2NM_198904.4 linkc.691G>T p.Asp231Tyr missense_variant Exon 6 of 10 ENST00000639213.2 NP_944494.1 P18507-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GABRG2ENST00000639213.2 linkc.691G>T p.Asp231Tyr missense_variant Exon 6 of 10 1 NM_198904.4 ENSP00000491909.2 P18507-2

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
Data not reliable, filtered out with message: AC0
AF:
0.00
AC:
0
AN:
1461662
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727134
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39644
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53404
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111880
Other (OTH)
AF:
0.00
AC:
0
AN:
60388
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

EPILEPSY, CHILDHOOD ABSENCE, SUSCEPTIBILITY TO, 2;C1969810:Febrile seizures, familial, 8 Uncertain:1
Nov 13, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with tyrosine, which is neutral and polar, at codon 231 of the GABRG2 protein (p.Asp231Tyr). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with GABRG2-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GABRG2 protein function with a positive predictive value of 95%. 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
AlphaMissense
Pathogenic
0.74
BayesDel_addAF
Pathogenic
0.41
D
BayesDel_noAF
Pathogenic
0.35
CADD
Pathogenic
32
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.77
.;.;.;.;.;.;D;.;.;.;.;.;.;.
Eigen
Pathogenic
0.90
Eigen_PC
Pathogenic
0.87
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP
Uncertain
0.10
D
MetaRNN
Pathogenic
0.87
D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.50
D
MutationAssessor
Uncertain
2.5
.;.;.;.;M;.;M;.;.;.;.;.;.;.
PhyloP100
8.1
PrimateAI
Pathogenic
0.80
T
PROVEAN
Pathogenic
-5.7
.;.;.;.;.;.;.;.;.;.;.;D;.;.
REVEL
Pathogenic
0.87
Sift
Uncertain
0.0010
.;.;.;.;.;.;.;.;.;.;.;D;.;.
Sift4G
Uncertain
0.0060
.;.;.;.;.;.;.;.;.;.;.;D;.;.
Polyphen
1.0
.;.;.;.;D;.;D;.;.;.;.;.;.;.
Vest4
0.77
MutPred
0.60
.;.;.;.;Loss of disorder (P = 0.0448);.;Loss of disorder (P = 0.0448);.;Loss of disorder (P = 0.0448);.;Loss of disorder (P = 0.0448);.;.;Loss of disorder (P = 0.0448);
MVP
0.91
MPC
2.8
ClinPred
0.99
D
GERP RS
5.6
Varity_R
0.91
gMVP
0.83
Mutation Taster
=9/91
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: rs773065895; hg19: chr5-161530954; API