5-161895648-T-A

Variant names:

• chr5-161895648-T-A
• rs78782356
• NM_001127644.2:c.857-18T>A

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6_Moderate

The NM_001127644.2(GABRA1):​c.857-18T>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000125 in 1,596,012 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0000067 (0 hom., cov: 31)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: GABRA1 NM_001127644.2 intron
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -1.28
• Publications: 4 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_benign. The variant received -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BP6: Variant 5-161895648-T-A is Benign according to our data. Variant chr5-161895648-T-A is described in ClinVar as [Likely_benign]. Clinvar id is 1668648.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GABRA1	NM_001127644.2	c.857-18T>A		intron_variant	Intron 8 of 9	ENST00000393943.10	NP_001121116.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GABRA1	ENST00000393943.10	c.857-18T>A		intron_variant	Intron 8 of 9	1	NM_001127644.2	ENSP00000377517.4

Frequencies

GnomAD3 genomes AF: 0.00000669 AC: 1 AN: 149584 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000251

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.91e-7 AC: 1 AN: 1446428 Hom.: 0 Cov.: 34 AF XY: 0.00000139 AC XY: 1 AN XY: 719658

African (AFR) AF: 0.0000302 AC: 1 AN: 33140

American (AMR) AF: 0.00 AC: 0 AN: 44002

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25950

East Asian (EAS) AF: 0.00 AC: 0 AN: 39442

South Asian (SAS) AF: 0.00 AC: 0 AN: 85426

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52696

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5736

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1100196

Other (OTH) AF: 0.00 AC: 0 AN: 59840

GnomAD4 genome AF: 0.00000669 AC: 1 AN: 149584 Hom.: 0 Cov.: 31 AF XY: 0.0000137 AC XY: 1 AN XY: 73044

African (AFR) AF: 0.0000251 AC: 1 AN: 39912

American (AMR) AF: 0.00 AC: 0 AN: 15106

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3462

East Asian (EAS) AF: 0.00 AC: 0 AN: 5140

South Asian (SAS) AF: 0.00 AC: 0 AN: 4794

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10440

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67442

Other (OTH) AF: 0.00 AC: 0 AN: 2060

Alfa AF: 0.00 Hom.: 130

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Aug 10, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	2.6
DANN	Benign	0.46
PhyloP100		-1.3

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

Other links and lift over

dbSNP: rs78782356; hg19: chr5-161322654;