rs752746786

Positions:

• chr1-1806503-A-C
• chr1-1806503-A-G
• chr1-1806503-A-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PM5 PP2 PP3 PP5_Very_Strong

The NM_002074.5(GNB1):​c.239T>G​(p.Ile80Ser) 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I80N) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GNB1 NM_002074.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 9.08

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 16 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, 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 chr1-1806503-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 224715.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, 0.834
• PP5: Variant 1-1806503-A-C is Pathogenic according to our data. Variant chr1-1806503-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 391609.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNB1	NM_002074.5	c.239T>G	p.Ile80Ser	missense_variant	6/12	ENST00000378609.9	NP_002065.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNB1	ENST00000378609.9	c.239T>G	p.Ile80Ser	missense_variant	6/12	1	NM_002074.5	ENSP00000367872.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Intellectual disability, autosomal dominant 42 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

MGZ Medical Genetics Center

Aug 26, 2021

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jun 13, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.26
CADD	Pathogenic	32
DANN	Benign	0.97
DEOGEN2	Uncertain	0.44	T;T;T;.;.
Eigen	Uncertain	0.67
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;.;D;D;D
M_CAP	Benign	0.044	D
MetaRNN	Pathogenic	0.83	D;D;D;D;D
MetaSVM	Benign	-0.47	T
MutationAssessor	Benign	1.9	L;L;.;.;.
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-5.0	.;D;D;D;D
REVEL	Uncertain	0.56
Sift	Pathogenic	0.0	.;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;.;.;.
Polyphen		1.0	D;D;.;.;.
Vest4		0.93
MutPred		0.54		Gain of disorder (P = 0.0063);Gain of disorder (P = 0.0063);.;Gain of disorder (P = 0.0063);Gain of disorder (P = 0.0063);
MVP		0.96
MPC		4.0
ClinPred		1.0	D
GERP RS		4.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.96
gMVP		0.94

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: rs752746786; hg19: chr1-1737942; COSMIC: COSV105931388;