rs1554689315

Variant names:

• chr9-98306236-A-T
• rs1554689315
• NM_005458.8:c.2114T>A

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PP3_Moderate PP5

The NM_005458.8(GABBR2):​c.2114T>A​(p.Ile705Asn) 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). Synonymous variant affecting the same amino acid position (i.e. I705I) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GABBR2 NM_005458.8 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 9.11
• Publications: 0 publications found

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]

GABBR2 Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 59

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• neurodevelopmental disorder with poor language and loss of hand skills

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• complex neurodevelopmental disorder

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen
• atypical Rett syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 7 uncertain in NM_005458.8
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.891
• PP5: Variant 9-98306236-A-T is Pathogenic according to our data. Variant chr9-98306236-A-T is described in ClinVar as Pathogenic. ClinVar VariationId is 496590.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005458.8. 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
	GABBR2	NM_005458.8	MANE Select	c.2114T>A	p.Ile705Asn	missense	Exon 15 of 19	NP_005449.5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GABBR2	ENST00000259455.4	TSL:1 MANE Select	c.2114T>A	p.Ile705Asn	missense	Exon 15 of 19	ENSP00000259455.2	O75899
	GABBR2	ENST00000931526.1		c.2048T>A	p.Ile683Asn	missense	Exon 14 of 18	ENSP00000601585.1
	GABBR2	ENST00000947376.1		c.2033T>A	p.Ile678Asn	missense	Exon 14 of 18	ENSP00000617435.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Developmental and epileptic encephalopathy, 59 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Pathogenic	33
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.81	D
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D
M_CAP	Pathogenic	0.62	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Pathogenic	0.84	D
MutationAssessor	Benign	2.0	M
PhyloP100		9.1
PrimateAI	Pathogenic	0.91	D
PROVEAN	Uncertain	-4.0	D
REVEL	Pathogenic	0.91
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		0.99	D
Vest4		0.91
MutPred		0.61		Gain of sheet (P = 0.1208)
MVP		0.95
MPC		2.4
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.95
gMVP		0.99
Mutation Taster		=13/87	disease causing (ClinVar)

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: rs1554689315; hg19: chr9-101068518;