3-30672309-G-C

Variant names:

• chr3-30672309-G-C
• rs755967723
• NM_003242.6:c.1126G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP2 PP3

The NM_003242.6(TGFBR2):​c.1126G>C​(p.Val376Leu) 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 nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V376M) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TGFBR2 NM_003242.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.08
• Publications: 3 publications found

Genes affected

TGFBR2 (HGNC:11773): (transforming growth factor beta receptor 2) The protein encoded by this gene is a transmembrane protein that has a protein kinase domain, forms a heterodimeric complex with TGF-beta receptor type-1, and binds TGF-beta. This receptor/ligand complex phosphorylates proteins, which then enter the nucleus and regulate the transcription of genes related to cell proliferation, cell cycle arrest, wound healing, immunosuppression, and tumorigenesis. Mutations in this gene have been associated with Marfan Syndrome, Loeys-Deitz Aortic Aneurysm Syndrome, and the development of various types of tumors. Alternatively spliced transcript variants encoding different isoforms have been characterized. [provided by RefSeq, Aug 2017]

TGFBR2 Gene-Disease associations (from GenCC):

• familial thoracic aortic aneurysm and aortic dissection

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Loeys-Dietz syndrome 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), PanelApp Australia, Genomics England PanelApp, G2P
• Loeys-Dietz syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 16 uncertain in NM_003242.6
• 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 91 curated pathogenic missense variants (we use a threshold of 10). The gene has 9 curated benign missense variants. Gene score misZ: 2.2437 (below the threshold of 3.09). Trascript score misZ: 2.9378 (below the threshold of 3.09). GenCC associations: The gene is linked to Loeys-Dietz syndrome, familial thoracic aortic aneurysm and aortic dissection, Loeys-Dietz syndrome 2.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.785

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TGFBR2	NM_003242.6	c.1126G>C	p.Val376Leu	missense_variant	Exon 4 of 7	ENST00000295754.10	NP_003233.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TGFBR2	ENST00000295754.10	c.1126G>C	p.Val376Leu	missense_variant	Exon 4 of 7	1	NM_003242.6	ENSP00000295754.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1

Dec 12, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with TGFBR2-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces valine with leucine at codon 376 of the TGFBR2 protein (p.Val376Leu). The valine residue is highly conserved and there is a small physicochemical difference between valine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.16
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.68	D;.
Eigen	Uncertain	0.54
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D;D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.78	D;D
MetaSVM	Uncertain	0.77	D
MutationAssessor	Benign	0.54	N;.
PhyloP100		8.1
PrimateAI	Pathogenic	0.86	D
PROVEAN	Benign	-1.6	N;N
REVEL	Pathogenic	0.81
Sift	Uncertain	0.0040	D;D
Sift4G	Uncertain	0.0090	D;D
Polyphen		0.91	P;.
Vest4		0.61
MutPred		0.66		Loss of glycosylation at P371 (P = 0.0388);.;
MVP		1.0
MPC		1.3
ClinPred		0.93	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.89
gMVP		0.76
Mutation Taster		=62/38	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: rs755967723; hg19: chr3-30713801;