5-162153176-C-G

Variant names:

• chr5-162153176-C-G
• NM_198904.4:c.1236C>G
• GABRG2 p.Tyr412*

Variant summary

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

The NM_198904.4(GABRG2):​c.1236C>G​(p.Tyr412*) 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. Y412Y) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GABRG2 NM_198904.4 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.248
• Publications: 0 publications found

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]

GABRG2 Gene-Disease associations (from GenCC):

• epilepsy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• developmental and epileptic encephalopathy, 74

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• febrile seizures, familial, 8

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• Dravet syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• generalized epilepsy with febrile seizures plus

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• self-limited epilepsy with centrotemporal spikes

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• undetermined early-onset epileptic encephalopathy

  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. There are 10 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_198904.4. 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
	GABRG2	NM_198904.4	MANE Select	c.1236C>G	p.Tyr412*	stop_gained	Exon 10 of 10	NP_944494.1	P18507-2
	GABRG2	NM_198903.2		c.1356C>G	p.Tyr452*	stop_gained	Exon 11 of 11	NP_944493.2	P18507-3
	GABRG2	NM_001375343.1		c.1332C>G	p.Tyr444*	stop_gained	Exon 10 of 10	NP_001362272.1	A0A1X7SBZ8

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GABRG2	ENST00000639213.2	TSL:1 MANE Select	c.1236C>G	p.Tyr412*	stop_gained	Exon 10 of 10	ENSP00000491909.2	P18507-2
	GABRG2	ENST00000414552.6	TSL:1	c.1356C>G	p.Tyr452*	stop_gained	Exon 11 of 11	ENSP00000410732.2	P18507-3
	GABRG2	ENST00000639111.2	TSL:1	c.1212C>G	p.Tyr404*	stop_gained	Exon 9 of 9	ENSP00000492125.2	P18507-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	29
DANN	Uncertain	0.98
Eigen	Benign	-0.18
Eigen_PC	Benign	-0.43
FATHMM_MKL	Uncertain	0.76	D
PhyloP100		-0.25
Mutation Taster		=3/197	disease causing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr5-161580182;