chr15-26561102-T-C

Variant names:

• chr15-26561102-T-C
• rs1555401426
• NM_000814.6:c.910A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_000814.6(GABRB3):​c.910A>G​(p.Lys304Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K304R) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: GABRB3 NM_000814.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.90
• Publications: 0 publications found

Genes affected

GABRB3 (HGNC:4083): (gamma-aminobutyric acid type A receptor subunit beta3) This gene encodes a member of the ligand-gated ionic channel family. The encoded protein is one the subunits of a multi-subunit chloride channel that serves as the receptor for gamma-aminobutyric acid, a major inhibitory neurotransmitter of the mammalian nervous system. This gene is located on the long arm of chromosome 15 in a cluster with two other genes encoding related subunits of the family. This gene may be associated with the pathogenesis of several disorders including Angelman syndrome, Prader-Willi syndrome, nonsyndromic orofacial clefts, epilepsy and autism. Alternatively spliced transcript variants encoding distinct isoforms have been described. [provided by RefSeq, Jul 2013]

GABRB3 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 43

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• epilepsy, childhood absence, susceptibility to, 5

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

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• childhood absence epilepsy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Lennox-Gastaut syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 13 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000814.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr15-26561101-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 1003531.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.929

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000814.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GABRB3	NM_000814.6	MANE Select	c.910A>G	p.Lys304Glu	missense	Exon 8 of 9	NP_000805.1	P28472-1
	GABRB3	NM_021912.5		c.910A>G	p.Lys304Glu	missense	Exon 8 of 9	NP_068712.1	X5DQY4
	GABRB3	NM_001191321.3		c.697A>G	p.Lys233Glu	missense	Exon 6 of 7	NP_001178250.1	P28472-3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GABRB3	ENST00000311550.10	TSL:1 MANE Select	c.910A>G	p.Lys304Glu	missense	Exon 8 of 9	ENSP00000308725.5	P28472-1
	GABRB3	ENST00000541819.6	TSL:1	c.1078A>G	p.Lys360Glu	missense	Exon 9 of 10	ENSP00000442408.2	F5H7N0
	GABRB3	ENST00000299267.9	TSL:1	c.910A>G	p.Lys304Glu	missense	Exon 8 of 9	ENSP00000299267.4	P28472-2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Epilepsy, childhood absence, susceptibility to, 1;C2677087:Epilepsy, childhood absence, susceptibility to, 5 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	31
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.94	D
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.92	D
M_CAP	Pathogenic	0.75	D
MetaRNN	Pathogenic	0.93	D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Pathogenic	4.5	H
PhyloP100		7.9
PrimateAI	Pathogenic	0.90	D
PROVEAN	Uncertain	-3.8	D
REVEL	Pathogenic	0.92
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.91
MutPred		0.70		Loss of methylation at K360 (P = 0.0099)
MVP		0.97
MPC		2.8
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.97
gMVP		0.99

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: rs1555401426; hg19: chr15-26806249;