rs551045474

chr5-161895763-C-T

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_Strong BP6 BP7 BS1 BS2

The NM_001127644.2(GABRA1):c.954C>T(p.Ala318=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000155 in 1,613,918 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00012 (0 hom., cov: 31)
  • Exomes 𝑓: 0.00016 (1 hom.)
• Consequence: GABRA1 NM_001127644.2 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:3
• Conservation: PhyloP100: -1.53

Genes affected

GABRA1 (HGNC:4075): (gamma-aminobutyric acid type A receptor subunit alpha1) This gene encodes a gamma-aminobutyric acid (GABA) receptor. 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. GABA-A receptors are pentameric, consisting of proteins from several subunit classes: alpha, beta, gamma, delta and rho. Mutations in this gene cause juvenile myoclonic epilepsy and childhood absence epilepsy type 4. Multiple transcript variants encoding the same protein have been identified for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Benign. Variant got -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.64).
• BP6: Variant 5-161895763-C-T is Benign according to our data. Variant chr5-161895763-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 137412.We mark this variant Likely_benign, oryginal submissions are: {Benign=2, Likely_benign=1, Uncertain_significance=1}. Variant chr5-161895763-C-T is described in Lovd as [Likely_benign].
• BP7: Synonymous conserved (PhyloP=-1.53 with no splicing effect.
• BS1: Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000118 (18/152140) while in subpopulation SAS AF= 0.00228 (11/4814). AF 95% confidence interval is 0.00128. There are 0 homozygotes in gnomad4. There are 12 alleles in male gnomad4 subpopulation. This position pass quality control queck.
• BS2: High AC in GnomAd at 18 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GABRA1	NM_001127644.2	c.954C>T	p.Ala318=	synonymous_variant	9/10	ENST00000393943.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GABRA1	ENST00000393943.10	c.954C>T	p.Ala318=	synonymous_variant	9/10	1	NM_001127644.2	P1

Frequencies

GnomAD3 genomes AF: 0.000118 AC: 18 AN: 152022 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00228

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000882

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000223 AC: 56 AN: 251392 Hom.: 1 AF XY: 0.000294 AC XY: 40 AN XY: 135870

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000327

Gnomad SAS exome AF: 0.00134

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000704

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.000159 AC: 232 AN: 1461778 Hom.: 1 Cov.: 35 AF XY: 0.000216 AC XY: 157 AN XY: 727186

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000756

Gnomad4 SAS exome AF: 0.00163

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000666

Gnomad4 OTH exome AF: 0.000199

GnomAD4 genome AF: 0.000118 AC: 18 AN: 152140 Hom.: 0 Cov.: 31 AF XY: 0.000161 AC XY: 12 AN XY: 74362

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00229

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000882

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000575 Hom.: 0

Bravo AF: 0.0000642

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Epilepsy, idiopathic generalized, susceptibility to, 13 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not specified Benign:1

Benign, criteria provided, single submitter

clinical testing

GeneDx

Sep 24, 2013

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Idiopathic generalized epilepsy;C1970160:Epilepsy, childhood absence 4;C4013473:Epilepsy, idiopathic generalized, susceptibility to, 13 Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Dec 11, 2023

- -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Mar 01, 2023

GABRA1: BP4, BP7, BS1 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.64
Cadd	Benign	7.6
Dann	Benign	0.55

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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

Other links and lift over

dbSNP: rs551045474; hg19: chr5-161322769;