9-98290633-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 1P and 1B. PP2BP4

The NM_005458.8(GABBR2):c.2777G>A(p.Arg926His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000624 in 1,441,330 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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. R926C) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

GABBR2
NM_005458.8 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.90

Variant links:

Genes affected

GABBR2 (HGNC:4507): (gamma-aminobutyric acid type B receptor subunit 2) The multi-pass membrane protein encoded by this gene belongs to the G-protein coupled receptor 3 family and GABA-B receptor subfamily. The GABA-B receptors inhibit neuronal activity through G protein-coupled second-messenger systems, which regulate the release of neurotransmitters, and the activity of ion channels and adenylyl cyclase. This receptor subunit forms an active heterodimeric complex with GABA-B receptor subunit 1, neither of which is effective on its own. Allelic variants of this gene have been associated with nicotine dependence.[provided by RefSeq, Jan 2010]

GABBR2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PP2

Missense variant where missense usually causes diseases, GABBR2

BP4

Computational evidence support a benign effect (MetaRNN=0.39879245).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
GABBR2	NM_005458.8 linkuse as main transcript	c.2777G>A	p.Arg926His	missense_variant	19/19	ENST00000259455.4
GABBR2	XM_017015331.3 linkuse as main transcript	c.2483G>A	p.Arg828His	missense_variant	18/18
GABBR2	XM_005252316.6 linkuse as main transcript	c.2003G>A	p.Arg668His	missense_variant	17/17
GABBR2	XM_017015332.3 linkuse as main transcript	c.2003G>A	p.Arg668His	missense_variant	16/16

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GABBR2	ENST00000259455.4 linkuse as main transcript	c.2777G>A	p.Arg926His	missense_variant	19/19	1	NM_005458.8	P1
GABBR2	ENST00000637410.1 linkuse as main transcript			downstream_gene_variant		5

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152008

Hom.:

Cov.:

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000260

AC:

AN:

115384

Hom.:

AF XY:

0.0000467

AC XY:

AN XY:

64196

show subpopulations

Gnomad AFR exome

AF:

0.000143

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000855

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000167

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000620

AC:

AN:

1289322

Hom.:

Cov.:

AF XY:

0.00000475

AC XY:

AN XY:

631304

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:

0.0000177

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000678

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152008

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74232

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:

0.0000147

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 18, 2023

The c.2777G>A (p.R926H) alteration is located in exon 19 (coding exon 19) of the GABBR2 gene. This alteration results from a G to A substitution at nucleotide position 2777, causing the arginine (R) at amino acid position 926 to be replaced by a histidine (H). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Epileptic encephalopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 25, 2023

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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 2476373). This variant has not been reported in the literature in individuals affected with GABBR2-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 926 of the GABBR2 protein (p.Arg926His). -

Developmental and epileptic encephalopathy, 59

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center

Mar 29, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.21

BayesDel_addAF

Uncertain

0.021

BayesDel_noAF

Uncertain

-0.010

Cadd

Pathogenic

Dann

Pathogenic

1.0

DEOGEN2

Benign

0.088

Eigen

Pathogenic

0.69

Eigen_PC

Pathogenic

0.74

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.95

M_CAP

Benign

0.080

MetaRNN

Benign

0.40

MetaSVM

Uncertain

0.24

MutationAssessor

Benign

0.55

MutationTaster

Benign

1.0

PrimateAI

Pathogenic

0.80

PROVEAN

Benign

-0.74

REVEL

Uncertain

0.39

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.48

MutPred

0.18

Loss of MoRF binding (P = 0.0707);

MVP

0.74

MPC

2.2

ClinPred

0.65

GERP RS

5.5

Varity_R

0.45

gMVP

0.34

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

LitVar

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

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over