9-98306266-C-A

Position:

• chr9-98306266-C-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_005458.8(GABBR2):​c.2084G>T​(p.Ser695Ile) 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. Variant has been reported in ClinVar as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S695N) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GABBR2 NM_005458.8 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.73

Genes affected

GABBR2 (HGNC:4507): (gamma-aminobutyric acid type B receptor subunit 2) The multi-pass membrane protein encoded by this gene belongs to the G-protein coupled receptor 3 family and GABA-B receptor subfamily. The GABA-B receptors inhibit neuronal activity through G protein-coupled second-messenger systems, which regulate the release of neurotransmitters, and the activity of ion channels and adenylyl cyclase. This receptor subunit forms an active heterodimeric complex with GABA-B receptor subunit 1, neither of which is effective on its own. Allelic variants of this gene have been associated with nicotine dependence.[provided by RefSeq, Jan 2010]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 4 uncertain in NM_005458.8
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-98306266-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1691275.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), GABBR2. . Gene score misZ 4.6253 (greater than the threshold 3.09). Trascript score misZ 4.0975 (greater than threshold 3.09). GenCC has associacion of gene with developmental and epileptic encephalopathy, 59, neurodevelopmental disorder with poor language and loss of hand skills, atypical Rett syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.971
• PP5: Variant 9-98306266-C-A is Pathogenic according to our data. Variant chr9-98306266-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 496589.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GABBR2	NM_005458.8	c.2084G>T	p.Ser695Ile	missense_variant	15/19	ENST00000259455.4
GABBR2	XM_017015331.3	c.1790G>T	p.Ser597Ile	missense_variant	14/18
GABBR2	XM_005252316.6	c.1310G>T	p.Ser437Ile	missense_variant	13/17
GABBR2	XM_017015332.3	c.1310G>T	p.Ser437Ile	missense_variant	12/16

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GABBR2	ENST00000259455.4	c.2084G>T	p.Ser695Ile	missense_variant	15/19	1	NM_005458.8	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Developmental and epileptic encephalopathy, 59 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Oct 02, 2014

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.77	D;.
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.92	D;D
M_CAP	Pathogenic	0.46	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Benign	1.5	L;.
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.91	D
PROVEAN	Pathogenic	-5.2	D;.
REVEL	Pathogenic	0.97
Sift	Uncertain	0.0010	D;.
Sift4G	Uncertain	0.0030	D;.
Polyphen		1.0	D;.
Vest4		0.83
MutPred		0.88		Loss of sheet (P = 0.0817);.;
MVP		1.0
MPC		2.1
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.95
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: rs1554689319; hg19: chr9-101068548;