5-162142211-G-C

Position:

• chr5-162142211-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_198904.4(GABRG2):​c.817G>C​(p.Gly273Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 152,018 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: GABRG2 NM_198904.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.88

Genes affected

GABRG2 (HGNC:4087): (gamma-aminobutyric acid type A receptor subunit gamma2) This gene encodes a gamma-aminobutyric acid (GABA) receptor. GABA is the major inhibitory neurotransmitter in the mammlian brain, where it acts at GABA-A receptors, which are ligand-gated chloride channels. GABA-A receptors are pentameric, consisting of proteins from several subunit classes: alpha, beta, gamma, delta and rho. Mutations in this gene have been associated with epilepsy and febrile seizures. Multiple transcript variants encoding different isoforms have been identified for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_198904.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), GABRG2. . Gene score misZ 2.9939 (greater than the threshold 3.09). Trascript score misZ 3.9213 (greater than threshold 3.09). GenCC has associacion of gene with epilepsy, Dravet syndrome, undetermined early-onset epileptic encephalopathy, generalized epilepsy with febrile seizures plus, developmental and epileptic encephalopathy, 74, febrile seizures, familial, 8, childhood epilepsy with centrotemporal spikes.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.938

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GABRG2	NM_198904.4	c.817G>C	p.Gly273Arg	missense_variant	7/10	ENST00000639213.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GABRG2	ENST00000639213.2	c.817G>C	p.Gly273Arg	missense_variant	7/10	1	NM_198904.4	A1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152018 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000242

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 Cov.: 31

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152018 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74250

Gnomad4 AFR AF: 0.0000242

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.87	.;.;.;.;.;.;D;.;.;.;.;.;.;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.41	D
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.78	D
MutationAssessor	Uncertain	2.8	.;.;.;.;M;.;M;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-7.3	.;.;.;.;.;.;.;.;.;.;.;D;.;.
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	.;.;.;.;.;.;.;.;.;.;.;D;.;.
Sift4G	Pathogenic	0.0	.;.;.;.;.;.;.;.;.;.;.;D;.;.
Polyphen		1.0	.;.;.;.;D;.;D;.;.;.;.;.;.;.
Vest4		0.95
MutPred		0.77		.;.;.;.;Gain of methylation at G273 (P = 0.0191);.;Gain of methylation at G273 (P = 0.0191);.;Gain of methylation at G273 (P = 0.0191);.;Gain of methylation at G273 (P = 0.0191);.;.;Gain of methylation at G273 (P = 0.0191);
MVP		0.97
MPC		2.8
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.93
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

Publications

LitVar

Other links and lift over

dbSNP: rs1469287853; hg19: chr5-161569217;