NM_004612.4:c.820A>C

Variant names:

• chr9-99142550-A-C
• rs863223816
• NM_004612.4:c.820A>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP3

The NM_004612.4(TGFBR1):​c.820A>C​(p.Thr274Pro) 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 variant affecting the same amino acid position, but resulting in a different missense (i.e. T274A) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TGFBR1 NM_004612.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.32
• Publications: 3 publications found

Genes affected

TGFBR1 (HGNC:11772): (transforming growth factor beta receptor 1) The protein encoded by this gene forms a heteromeric complex with type II TGF-beta receptors when bound to TGF-beta, transducing the TGF-beta signal from the cell surface to the cytoplasm. The encoded protein is a serine/threonine protein kinase. Mutations in this gene have been associated with Loeys-Dietz aortic aneurysm syndrome (LDAS). Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2008]

TGFBR1 Gene-Disease associations (from GenCC):

• familial thoracic aortic aneurysm and aortic dissection

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

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• Loeys-Dietz syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia, Genomics England PanelApp, G2P
• multiple self-healing squamous epithelioma

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_004612.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-99142550-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 213879.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.794

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TGFBR1	NM_004612.4	c.820A>C	p.Thr274Pro	missense_variant	Exon 5 of 9	ENST00000374994.9	NP_004603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TGFBR1	ENST00000374994.9	c.820A>C	p.Thr274Pro	missense_variant	Exon 5 of 9	1	NM_004612.4	ENSP00000364133.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

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

Mar 05, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine with proline at codon 274 of the TGFBR1 protein (p.Thr274Pro). The threonine residue is highly conserved and there is a small physicochemical difference between threonine and proline. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a TGFBR1-related disease. This variant has been reported to segregate with aortopathy in a single family (Invitae). 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. In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.23
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.46	T;.;.;.
Eigen	Uncertain	0.58
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D;D;D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.79	D;D;D;D
MetaSVM	Uncertain	-0.28	T
MutationAssessor	Benign	1.9	L;.;.;.
PhyloP100		9.3
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-5.8	D;D;D;D
REVEL	Pathogenic	0.65
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Uncertain	0.012	D;T;D;D
Polyphen		1.0	D;B;.;.
Vest4		0.76
MutPred		0.58		Gain of loop (P = 0.2045);.;.;.;
MVP		0.92
MPC		1.9
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.98
gMVP		0.96
Mutation Taster		=2/98	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.10		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: rs863223816; hg19: chr9-101904832;