3-30644854-A-C

Variant names:

• chr3-30644854-A-C
• rs1060501985
• NM_003242.6:c.202A>C

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 3P and 9B. PM2 PP2 BP4_Strong BP6 BS2

The NM_003242.6(TGFBR2):​c.202A>C​(p.Met68Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,838 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M68V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: TGFBR2 NM_003242.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: -0.112
• 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_benign. The variant received -6 ACMG points.

• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.0635083).
• BP6: Variant 3-30644854-A-C is Benign according to our data. Variant chr3-30644854-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 408443.
• BS2: High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TGFBR2	NM_003242.6	c.202A>C	p.Met68Leu	missense_variant	Exon 2 of 7	ENST00000295754.10	NP_003233.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TGFBR2	ENST00000295754.10	c.202A>C	p.Met68Leu	missense_variant	Exon 2 of 7	1	NM_003242.6	ENSP00000295754.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461838 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 727218

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111982

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1 Benign:1

Jun 03, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Sep 23, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine with leucine at codon 68 of the TGFBR2 protein (p.Met68Leu). The methionine residue is weakly conserved and there is a small physicochemical difference between methionine and leucine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a TGFBR2-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: (SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). The leucine amino acid residue is also found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies. In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.075
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.53
CADD	Benign	0.67
DANN	Benign	0.51
DEOGEN2	Benign	0.29	T;.
Eigen	Benign	-2.3
Eigen_PC	Benign	-2.3
FATHMM_MKL	Benign	0.12	N
LIST_S2	Benign	0.27	T;T
M_CAP	Benign	0.028	D
MetaRNN	Benign	0.064	T;T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	0.20	N;.
PhyloP100		-0.11
PrimateAI	Benign	0.25	T
PROVEAN	Benign	-0.35	N;N
REVEL	Uncertain	0.37
Sift	Benign	0.82	T;T
Sift4G	Benign	0.79	T;T
Polyphen		0.0	B;.
Vest4		0.090
MutPred		0.54		Gain of sheet (P = 0.0344);.;
MVP		0.51
MPC		0.50
ClinPred		0.021	T
GERP RS		-11
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.19
gMVP		0.13
Mutation Taster		=92/8	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: rs1060501985; hg19: chr3-30686346;