chr1-1787384-C-T

Variant names:

• chr1-1787384-C-T
• NM_002074.5:c.970G>A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_002074.5(GNB1):​c.970G>A​(p.Gly324Ser) 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G324D) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GNB1 NM_002074.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.73

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the GNB1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 33 curated pathogenic missense variants (we use a threshold of 10). The gene has 19 curated benign missense variants. Gene score misZ: 3.8328 (above the threshold of 3.09). Trascript score misZ: 3.4817 (above the threshold of 3.09). GenCC associations: The gene is linked to intellectual disability, autosomal dominant 42.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.901

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNB1	NM_002074.5	c.970G>A	p.Gly324Ser	missense_variant	Exon 11 of 12	ENST00000378609.9	NP_002065.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GNB1	ENST00000378609.9	c.970G>A	p.Gly324Ser	missense_variant	Exon 11 of 12	1	NM_002074.5	ENSP00000367872.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Dec 08, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 324 of the GNB1 protein (p.Gly324Ser). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with GNB1-related conditions. 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 with a positive predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.45	T;T;T
Eigen	Uncertain	0.55
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;D;.
M_CAP	Benign	0.042	D
MetaRNN	Pathogenic	0.90	D;D;D
MetaSVM	Benign	-0.31	T
MutationAssessor	Uncertain	2.2	M;.;M
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-5.4	.;.;D
REVEL	Uncertain	0.62
Sift	Uncertain	0.0010	.;.;D
Sift4G	Uncertain	0.0040	D;D;D
Polyphen		1.0	D;.;D
Vest4		0.82
MutPred		0.82		Gain of sheet (P = 0.1539);.;Gain of sheet (P = 0.1539);
MVP		0.87
MPC		3.0
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.93
gMVP		0.78

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-1718823;