9-98290622-C-T

Position:

• chr9-98290622-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_005458.8(GABBR2):​c.2788G>A​(p.Val930Met) variant causes a missense change. The variant allele was found at a frequency of 0.00000155 in 1,289,238 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000016 (0 hom.)
• Consequence: GABBR2 NM_005458.8 missense
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 6.01

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), GABBR2. . Gene score misZ 4.6253 (greater than the threshold 3.09). Trascript score misZ 4.0975 (greater than threshold 3.09). GenCC has associacion of gene with developmental and epileptic encephalopathy, 59, neurodevelopmental disorder with poor language and loss of hand skills, atypical Rett syndrome.
• BP4: Computational evidence support a benign effect (MetaRNN=0.10675159).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GABBR2	NM_005458.8	c.2788G>A	p.Val930Met	missense_variant	19/19	ENST00000259455.4	NP_005449.5
GABBR2	XM_017015331.3	c.2494G>A	p.Val832Met	missense_variant	18/18		XP_016870820.1
GABBR2	XM_005252316.6	c.2014G>A	p.Val672Met	missense_variant	17/17		XP_005252373.1
GABBR2	XM_017015332.3	c.2014G>A	p.Val672Met	missense_variant	16/16		XP_016870821.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GABBR2	ENST00000259455.4	c.2788G>A	p.Val930Met	missense_variant	19/19	1	NM_005458.8	ENSP00000259455.2
GABBR2	ENST00000637410.1	n.*25G>A		downstream_gene_variant		5

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000155 AC: 2 AN: 1289238 Hom.: 0 Cov.: 31 AF XY: 0.00000158 AC XY: 1 AN XY: 631080

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: 0.00000194

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

GABBR2-related disorder Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

May 17, 2024

The GABBR2 c.2788G>A variant is predicted to result in the amino acid substitution p.Val930Met. To our knowledge, this variant has not been reported in the literature or in a large population database, indicating this variant is rare. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Benign	-0.061	T
BayesDel_noAF	Benign	-0.33
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.082	T
Eigen	Benign	0.0032
Eigen_PC	Uncertain	0.23
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.91	D
M_CAP	Benign	0.016	T
MetaRNN	Benign	0.11	T
MetaSVM	Benign	-0.72	T
MutationAssessor	Benign	0.0	N
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-0.11	N
REVEL	Benign	0.28
Sift	Benign	0.17	T
Sift4G	Benign	0.30	T
Polyphen		0.062	B
Vest4		0.12
MutPred		0.11		Gain of sheet (P = 0.0827);
MVP		0.49
MPC		0.92
ClinPred		0.74	D
GERP RS		5.5
Varity_R		0.14
gMVP		0.21

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr9-101052904;