5-161897155-C-G

Variant names:

• chr5-161897155-C-G
• rs771832995
• NM_001127644.2:c.1104C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_001127644.2(GABRA1):​c.1104C>G​(p.Tyr368*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. Y368Y) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GABRA1 NM_001127644.2 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.14
• Publications: 1 publications found

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]

GABRA1 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 19

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• genetic developmental and epileptic encephalopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• epilepsy, idiopathic generalized, susceptibility to, 13

  Inheritance: AD Classification: STRONG Submitted by: G2P
• Dravet syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• juvenile myoclonic epilepsy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.195 CDS is truncated, and there are 2 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GABRA1	NM_001127644.2	c.1104C>G	p.Tyr368*	stop_gained	Exon 10 of 10	ENST00000393943.10	NP_001121116.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GABRA1	ENST00000393943.10	c.1104C>G	p.Tyr368*	stop_gained	Exon 10 of 10	1	NM_001127644.2	ENSP00000377517.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251016 AF XY: 0.00000737

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	33
DANN	Uncertain	0.99
Eigen	Uncertain	0.21
Eigen_PC	Benign	-0.0034
FATHMM_MKL	Uncertain	0.82	D
PhyloP100		1.1
Vest4		0.97, 0.86, 0.86, 0.85
GERP RS		-1.8
Mutation Taster		=4/196	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs771832995; hg19: chr5-161324161;