3-179419444-C-T

Position:

• chr3-179419444-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP3_Strong PP5_Moderate

The NM_021629.4(GNB4):​c.158G>A​(p.Gly53Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,460,948 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GNB4 NM_021629.4 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 7.78

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.94
• PP5: Variant 3-179419444-C-T is Pathogenic according to our data. Variant chr3-179419444-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 41940.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr3-179419444-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNB4	NM_021629.4	c.158G>A	p.Gly53Asp	missense_variant	4/10	ENST00000232564.8	NP_067642.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNB4	ENST00000232564.8	c.158G>A	p.Gly53Asp	missense_variant	4/10	1	NM_021629.4	ENSP00000232564.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1460948 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 726896

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease dominant intermediate F Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 20, 2019	This sequence change replaces glycine with aspartic acid at codon 53 of the GNB4 protein (p.Gly53Asp). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and aspartic acid. This variant is not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with Charcot-Marie-Tooth disease (PMID: 23434117). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 41940). This variant has been reported to affect GNB4 protein function (PMID: 23434117). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Pathogenic, no assertion criteria provided	literature only	OMIM	Mar 07, 2013	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.30
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Benign	0.20	T;T;D
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	1.0	.;D;D
M_CAP	Pathogenic	0.53	D
MetaRNN	Pathogenic	0.94	D;D;D
MetaSVM	Uncertain	0.23	D
MutationAssessor	Uncertain	2.7	M;M;.
PrimateAI	Pathogenic	0.94	D
PROVEAN	Pathogenic	-5.9	D;D;D
REVEL	Pathogenic	0.86
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	D;D;.
Polyphen		1.0	D;D;.
Vest4		0.96
MutPred		0.81		Gain of glycosylation at T50 (P = 0.0053);Gain of glycosylation at T50 (P = 0.0053);Gain of glycosylation at T50 (P = 0.0053);
MVP		0.80
MPC		1.8
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.98
gMVP		0.72

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: rs387907340; hg19: chr3-179137232;