chr1-2027598-C-A

Variant names:

• chr1-2027598-C-A
• rs367776284
• NM_000815.5:c.492C>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000815.5(GABRD):​c.492C>A​(p.Cys164*) 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. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. C164C) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GABRD NM_000815.5 stop_gained
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.409
• Publications: 0 publications found

Genes affected

GABRD (HGNC:4084): (gamma-aminobutyric acid type A receptor subunit delta) Gamma-aminobutyric acid (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. The GABA-A receptor is generally pentameric and there are five types of subunits: alpha, beta, gamma, delta, and rho. This gene encodes the delta subunit. Mutations in this gene have been associated with susceptibility to generalized epilepsy with febrile seizures, type 5. Alternatively spliced transcript variants have been described for this gene, but their biological validity has not been determined. [provided by RefSeq, Jul 2008]

GABRD Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics, ClinGen
• epilepsy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• epilepsy, idiopathic generalized, susceptibility to, 10

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GABRD	NM_000815.5	c.492C>A	p.Cys164*	stop_gained	Exon 5 of 9	ENST00000378585.7	NP_000806.2
GABRD	XM_017000936.2	c.1197C>A	p.Cys399*	stop_gained	Exon 4 of 8		XP_016856425.1
GABRD	XM_011541194.4	c.531C>A	p.Cys177*	stop_gained	Exon 5 of 9		XP_011539496.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GABRD	ENST00000378585.7	c.492C>A	p.Cys164*	stop_gained	Exon 5 of 9	1	NM_000815.5	ENSP00000367848.4

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

Nov 02, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene or region of a gene for which loss of function is not a well-established mechanism of disease; Has not been previously published as pathogenic or benign to our knowledge; Not observed at significant frequency in large population cohorts (gnomAD) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Uncertain	24
DANN	Benign	0.97
Eigen	Benign	-0.28
Eigen_PC	Benign	-0.64
FATHMM_MKL	Benign	0.72	D
PhyloP100		-0.41
Vest4		0.97
GERP RS		-7.0
PromoterAI		-0.055	Neutral
Mutation Taster		=11/189	disease causing (fs/PTC)

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: rs367776284; hg19: chr1-1959037;