chr7-100676745-C-T

Variant names:

• chr7-100676745-C-T
• rs779612089
• NM_005273.4:c.149C>T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_005273.4(GNB2):​c.149C>T​(p.Thr50Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,455,156 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: GNB2 NM_005273.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.91
• Publications: 0 publications found

Genes affected

GNB2 (HGNC:4398): (G protein subunit beta 2) 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. This gene contains a trinucleotide (CCG) repeat length polymorphism in its 5' UTR. [provided by RefSeq, Jul 2008]

GNB2 Gene-Disease associations (from GenCC):

• neurodevelopmental disorder with hypotonia and dysmorphic facies

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• sick sinus syndrome 4

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_005273.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 8 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 3.214 (above the threshold of 3.09). Trascript score misZ: 3.0761 (below the threshold of 3.09). GenCC associations: The gene is linked to sick sinus syndrome 4, neurodevelopmental disorder with hypotonia and dysmorphic facies.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005273.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNB2	NM_005273.4	MANE Select	c.149C>T	p.Thr50Ile	missense	Exon 4 of 10	NP_005264.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNB2	ENST00000303210.9	TSL:1 MANE Select	c.149C>T	p.Thr50Ile	missense	Exon 4 of 10	ENSP00000305260.4	P62879-1
	GNB2	ENST00000393924.1	TSL:1	c.149C>T	p.Thr50Ile	missense	Exon 3 of 9	ENSP00000377501.1	P62879-1
	GNB2	ENST00000879679.1		c.149C>T	p.Thr50Ile	missense	Exon 4 of 10	ENSP00000549738.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000423 AC: 1 AN: 236652 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000308

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1455156 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 723616

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33440

American (AMR) AF: 0.0000232 AC: 1 AN: 43088

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25926

East Asian (EAS) AF: 0.00 AC: 0 AN: 39518

South Asian (SAS) AF: 0.00 AC: 0 AN: 85652

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52448

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1109152

Other (OTH) AF: 0.00 AC: 0 AN: 60170

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000825 AC: 1

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	2	-	not provided (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.62
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	0.0
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.19	T
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Benign	0.034	D
MetaRNN	Uncertain	0.61	D
MetaSVM	Benign	-0.53	T
MutationAssessor	Benign	1.7	L
PhyloP100		7.9
PrimateAI	Pathogenic	0.91	D
PROVEAN	Uncertain	-3.9	D
REVEL	Uncertain	0.29
Sift	Benign	0.049	D
Sift4G	Benign	0.21	T
Polyphen		0.37	B
Vest4		0.89
MutPred		0.48		Loss of phosphorylation at T50 (P = 0.0151)
MVP		0.56
MPC		1.8
ClinPred		0.94	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.40
gMVP		0.91
Mutation Taster		=53/47	polymorphism

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

Other links and lift over

dbSNP: rs779612089; hg19: chr7-100274368;