3-179401278-C-A

Position:

• chr3-179401278-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_021629.4(GNB4):​c.958G>T​(p.Val320Leu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign 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. V320I) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: GNB4 NM_021629.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.93

Genes affected

GNB4 (HGNC:20731): (G protein subunit beta 4) 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. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.39494002).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNB4	NM_021629.4	c.958G>T	p.Val320Leu	missense_variant	10/10	ENST00000232564.8	NP_067642.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNB4	ENST00000232564.8	c.958G>T	p.Val320Leu	missense_variant	10/10	1	NM_021629.4	ENSP00000232564.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease dominant intermediate F Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 19, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant has not been reported in the literature in individuals affected with GNB4-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 320 of the GNB4 protein (p.Val320Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.65
BayesDel_addAF	Uncertain	0.085	D
BayesDel_noAF	Benign	-0.12
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Benign	0.16	T;T
Eigen	Uncertain	0.21
Eigen_PC	Uncertain	0.28
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Pathogenic	0.98	.;D
M_CAP	Benign	0.058	D
MetaRNN	Benign	0.39	T;T
MetaSVM	Benign	-0.85	T
MutationAssessor	Benign	0.82	L;L
PrimateAI	Pathogenic	0.82	D
PROVEAN	Uncertain	-2.7	D;D
REVEL	Benign	0.28
Sift	Uncertain	0.0040	D;D
Sift4G	Benign	0.26	T;T
Polyphen		0.83	P;P
Vest4		0.48
MutPred		0.54		Loss of catalytic residue at V320 (P = 0.1404);Loss of catalytic residue at V320 (P = 0.1404);
MVP		0.56
MPC		0.69
ClinPred		0.97	D
GERP RS		4.0
Varity_R		0.49
gMVP		0.58

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.12		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: chr3-179119066;