rs1553194162

Positions:

• chr1-1804496-T-C

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate PP5_Very_Strong

The NM_002074.5(GNB1):​c.353A>G​(p.Asp118Gly) 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. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D118Y) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: GNB1 NM_002074.5 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2 O:1
• Conservation: PhyloP100: 7.84

Genes affected

GNB1 (HGNC:4396): (G protein subunit beta 1) Heterotrimeric guanine nucleotide-binding proteins (G proteins), which integrate signals between receptors and effector proteins, are composed of an alpha, a beta, and a gamma subunit. These subunits are encoded by families of related genes. This gene encodes a beta subunit. Beta subunits are important regulators of alpha subunits, as well as of certain signal transduction receptors and effectors. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2013]

GNB1 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 17 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 2 uncertain in NM_002074.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-1804497-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 812755.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), GNB1. . Gene score misZ 3.8328 (greater than the threshold 3.09). Trascript score misZ 3.4817 (greater than threshold 3.09). GenCC has associacion of gene with intellectual disability, autosomal dominant 42.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.933
• PP5: Variant 1-1804496-T-C is Pathogenic according to our data. Variant chr1-1804496-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 521213.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-1804496-T-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNB1	NM_002074.5	c.353A>G	p.Asp118Gly	missense_variant	7/12	ENST00000378609.9	NP_002065.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNB1	ENST00000378609.9	c.353A>G	p.Asp118Gly	missense_variant	7/12	1	NM_002074.5	ENSP00000367872.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1461386 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 727022

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 29, 2016

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 31, 2022

For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects GNB1 function (PMID: 28087732). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GNB1 protein function. ClinVar contains an entry for this variant (Variation ID: 521213). This missense change has been observed in individual(s) with an intellectual disability syndrome (PMID: 27668284, 30194818). In at least one individual the variant was observed to be de novo. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 118 of the GNB1 protein (p.Asp118Gly). -

Intellectual disability, autosomal dominant 42 Other:1

not provided, no classification provided

literature only

GeneReviews

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.47	T;T;T;T;.
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D;.;D;D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.1	H;.;H;.;.
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-6.2	.;.;D;D;D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	.;.;D;D;D
Sift4G	Uncertain	0.0030	D;D;D;.;.
Polyphen		0.99	D;.;D;.;.
Vest4		0.99
MutPred		0.69		Loss of catalytic residue at D118 (P = 0.05);.;Loss of catalytic residue at D118 (P = 0.05);.;Loss of catalytic residue at D118 (P = 0.05);
MVP		0.99
MPC		3.4
ClinPred		1.0	D
GERP RS		5.4
Varity_R		1.0
gMVP		0.96

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

Publications

LitVar

Other links and lift over

dbSNP: rs1553194162; hg19: chr1-1735935;