rs1554700666

Positions:

• chr9-99138051-A-G
• chr9-99138051-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The ENST00000374994.9(TGFBR1):​c.767A>G​(p.His256Arg) 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. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. H256H) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TGFBR1 ENST00000374994.9 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.27

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in ENST00000374994.9
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TGFBR1. . Gene score misZ 2.7935 (greater than the threshold 3.09). Trascript score misZ 3.6468 (greater than threshold 3.09). GenCC has associacion of gene with familial thoracic aortic aneurysm and aortic dissection, Loeys-Dietz syndrome, multiple self-healing squamous epithelioma, Loeys-Dietz syndrome 1.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TGFBR1	NM_004612.4	c.767A>G	p.His256Arg	missense_variant	4/9	ENST00000374994.9	NP_004603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TGFBR1	ENST00000374994.9	c.767A>G	p.His256Arg	missense_variant	4/9	1	NM_004612.4	ENSP00000364133	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 02, 2021	The p.H256R variant (also known as c.767A>G), located in coding exon 4 of the TGFBR1 gene, results from an A to G substitution at nucleotide position 767. The histidine at codon 256 is replaced by arginine, an amino acid with highly similar properties. This alteration has been reported in a Loeys-Dietz syndrome (LDS) cohort; however, clinical details were limited (Yang H et al. Orphanet J Rare Dis, 2020 01;15:6). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 02, 2017	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. 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. 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 sequence change replaces histidine with arginine at codon 256 of the TGFBR1 protein (p.His256Arg). The histidine residue is highly conserved and there is a small physicochemical difference between histidine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.56	D;.;.;D;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D
M_CAP	Pathogenic	0.40	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Pathogenic	4.2	H;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.94	D
PROVEAN	Pathogenic	-7.5	D;D;D;D;D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D
Polyphen		1.0	D;D;.;.;.
Vest4		0.96
MutPred		0.93		Gain of helix (P = 0.1736);.;.;.;.;
MVP		0.98
MPC		3.7
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.97
gMVP		0.99

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: rs1554700666; hg19: chr9-101900333;