5-161326441-C-A

Variant names:

• chr5-161326441-C-A
• NM_001371727.1:c.1118G>T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001371727.1(GABRB2):​c.1118G>T​(p.Arg373Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,308 control chromosomes in the GnomAD database, with no homozygous occurrence. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GABRB2 NM_001371727.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.12

Genes affected

GABRB2 (HGNC:4082): (gamma-aminobutyric acid type A receptor subunit beta2) The gamma-aminobutyric acid (GABA) A receptor is a multisubunit chloride channel that mediates the fastest inhibitory synaptic transmission in the central nervous system. This gene encodes GABA A receptor, beta 2 subunit. It is mapped to chromosome 5q34 in a cluster comprised of genes encoding alpha 1 and gamma 2 subunits of the GABA A receptor. Alternative splicing of this gene generates 2 transcript variants, differing by a 114 bp insertion. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the GABRB2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 45 curated pathogenic missense variants (we use a threshold of 10). The gene has 42 curated benign missense variants. Gene score misZ: 3.3968 (above the threshold of 3.09). Trascript score misZ: 4.0905 (above the threshold of 3.09). GenCC associations: The gene is linked to undetermined early-onset epileptic encephalopathy, epileptic encephalopathy, infantile or early childhood, 2.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GABRB2	NM_001371727.1	c.1118G>T	p.Arg373Leu	missense_variant	Exon 9 of 10	ENST00000393959.6	NP_001358656.1
GABRB2	NM_021911.3	c.1118G>T	p.Arg373Leu	missense_variant	Exon 10 of 11		NP_068711.1
GABRB2	NM_000813.3	c.1077+4442G>T		intron_variant	Intron 9 of 9		NP_000804.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GABRB2	ENST00000393959.6	c.1118G>T	p.Arg373Leu	missense_variant	Exon 9 of 10	1	NM_001371727.1	ENSP00000377531.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461308 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726962

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Intellectual disability Uncertain:1

Jul 13, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 373 of the GABRB2 protein (p.Arg373Leu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with GABRB2-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 not expected to disrupt GABRB2 protein function. 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	Benign	0.16
BayesDel_addAF	Benign	-0.043	T
BayesDel_noAF	Benign	-0.30
CADD	Benign	21
DANN	Uncertain	0.98
DEOGEN2	Benign	0.20	T;T
Eigen	Benign	-0.40
Eigen_PC	Benign	-0.22
FATHMM_MKL	Benign	0.68	D
LIST_S2	Benign	0.60	.;T
M_CAP	Benign	0.023	T
MetaRNN	Uncertain	0.61	D;D
MetaSVM	Benign	-0.88	T
MutationAssessor	Benign	0.34	N;N
PrimateAI	Uncertain	0.56	T
PROVEAN	Benign	-0.070	N;N
REVEL	Benign	0.29
Sift	Benign	0.27	T;T
Sift4G	Benign	0.33	T;T
Polyphen		0.0	B;B
Vest4		0.67
MutPred		0.65		Loss of MoRF binding (P = 0.0214);Loss of MoRF binding (P = 0.0214);
MVP		0.72
MPC		0.39
ClinPred		0.24	T
GERP RS		3.4
Varity_R		0.072
gMVP		0.65

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: chr5-160753448;