chr4-46250333-T-A

Position:

• chr4-46250333-T-A

Variant summary

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

The NM_000807.4(GABRA2):​c.1331A>T​(p.Glu444Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GABRA2 NM_000807.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.02

Genes affected

GABRA2 (HGNC:4076): (gamma-aminobutyric acid type A receptor subunit alpha2) GABA is the major inhibitory neurotransmitter in the mammalian brain where it acts at GABA-A receptors, which are ligand-gated chloride channels. Chloride conductance of these channels can be modulated by agents such as benzodiazepines that bind to the GABA-A receptor. At least 16 distinct subunits of GABA-A receptors have been identified. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2013]

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 gene, where missense usually causes diseases (based on misZ statistic), GABRA2. . Gene score misZ 3.1277 (greater than the threshold 3.09). Trascript score misZ 3.4041 (greater than threshold 3.09). GenCC has associacion of gene with developmental and epileptic encephalopathy, 78, undetermined early-onset epileptic encephalopathy.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GABRA2	NM_000807.4	c.1331A>T	p.Glu444Val	missense_variant	10/10	ENST00000381620.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GABRA2	ENST00000381620.9	c.1331A>T	p.Glu444Val	missense_variant	10/10	1	NM_000807.4	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 20, 2022

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. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant has not been reported in the literature in individuals affected with GABRA2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glutamic acid, which is acidic and polar, with valine, which is neutral and non-polar, at codon 504 of the GABRA2 protein (p.Glu504Val). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.25
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.49	T;T;T;T;T;T
Eigen	Pathogenic	0.70
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	.;.;.;D;D;D
M_CAP	Uncertain	0.15	D
MetaRNN	Uncertain	0.53	D;D;D;D;D;D
MetaSVM	Uncertain	0.35	D
MutationAssessor	Uncertain	2.1	M;M;M;M;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-3.6	D;D;D;D;.;D
REVEL	Pathogenic	0.80
Sift	Uncertain	0.0010	D;D;D;D;.;D
Sift4G	Uncertain	0.0040	D;D;D;D;D;D
Polyphen		0.99	D;D;D;D;.;.
Vest4		0.59
MutPred		0.42		Loss of disorder (P = 0.0259);Loss of disorder (P = 0.0259);Loss of disorder (P = 0.0259);Loss of disorder (P = 0.0259);.;.;
MVP		0.94
MPC		0.89
ClinPred		0.99	D
GERP RS		5.8
Varity_R		0.54
gMVP		0.68

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: chr4-46252350; COSMIC: COSV62914175;