NM_198904.4:c.853C>G

Variant names:

• chr5-162142247-C-G
• rs1554100507
• NM_198904.4:c.853C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3 PP5

The NM_198904.4(GABRG2):​c.853C>G​(p.Leu285Val) variant causes a missense 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 Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GABRG2 NM_198904.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 1.42
• 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, G2P, Labcorp Genetics (formerly Invitae)
• 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.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_198904.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.76
• PP5: Variant 5-162142247-C-G is Pathogenic according to our data. Variant chr5-162142247-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 521954.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GABRG2	NM_198904.4	c.853C>G	p.Leu285Val	missense_variant	Exon 7 of 10	ENST00000639213.2	NP_944494.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GABRG2	ENST00000639213.2	c.853C>G	p.Leu285Val	missense_variant	Exon 7 of 10	1	NM_198904.4	ENSP00000491909.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Developmental and epileptic encephalopathy, 74 Pathogenic:1

-

Kasturba Medical College, Manipal, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases Uncertain:1

Jul 28, 2017

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.10
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.53	.;.;.;.;.;.;D;.;.;.;.;.;.;.
Eigen	Uncertain	0.45
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.89	D;T;T;T;T;T;T;T;T;T;T;D;D;T
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.76	D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.72	D
MutationAssessor	Uncertain	2.4	.;.;.;.;M;.;M;.;.;.;.;.;.;.
PhyloP100		1.4
PrimateAI	Pathogenic	0.84	D
PROVEAN	Benign	-1.1	.;.;.;.;.;.;.;.;.;.;.;N;.;.
REVEL	Uncertain	0.59
Sift	Benign	0.33	.;.;.;.;.;.;.;.;.;.;.;T;.;.
Sift4G	Benign	0.17	.;.;.;.;.;.;.;.;.;.;.;T;.;.
Polyphen		0.50, 0.56	.;.;.;.;P;.;P;.;.;.;.;.;.;.
Vest4		0.57
MutPred		0.74		.;.;.;.;Gain of helix (P = 0.132);.;Gain of helix (P = 0.132);.;Gain of helix (P = 0.132);.;Gain of helix (P = 0.132);.;.;Gain of helix (P = 0.132);
MVP		0.76
MPC		2.6
ClinPred		0.80	D
GERP RS		5.8
Varity_R		0.83
gMVP		0.94
Mutation Taster		=21/79	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1554100507; hg19: chr5-161569253;