9-99132728-G-T

Position:

• chr9-99132728-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Strong

The NM_004612.4(TGFBR1):​c.563G>T​(p.Gly188Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,834 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TGFBR1 NM_004612.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 10.0

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 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• 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, 0.977

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TGFBR1	NM_004612.4	c.563G>T	p.Gly188Val	missense_variant	3/9	ENST00000374994.9	NP_004603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TGFBR1	ENST00000374994.9	c.563G>T	p.Gly188Val	missense_variant	3/9	1	NM_004612.4	ENSP00000364133.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461834 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727220

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 25, 2024

The p.G188V variant (also known as c.563G>T), located in coding exon 3 of the TGFBR1 gene, results from a G to T substitution at nucleotide position 563. The glycine at codon 188 is replaced by valine, an amino acid with dissimilar properties. This alteration alters the first amino acid of the highly conserved GS domain signature sequence (GSGSGLP) found in type I TGF beta receptors. This variant has been observed in at least three individuals with a personal and/or family history that is consistent with TGFBR1-related Loeys-Dietz syndrome and segregated with disease in at least one family (Ambry internal data; Ziganshin BA et al. Ann. Thorac. Surg. 2015;100:1604-11; Yamada S. Front Physiol. 2021 Aug;12:715687). Cells from aortic tissue of a heterozygous mouse model with this variant showed distorted and ruptured elastic fibers; however, the clinical relevance of this finding is unclear (Yamada S. Front Physiol. 2021 Aug;12:715687). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the supporting evidence, this variant is likely pathogenic for TGFBR1-related Loeys-Dietz syndrome. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Sep 12, 2023

Not observed at significant frequency in large population cohorts (gnomAD); Published functional studies show that this variant is embryonic lethality in homozygous state, and results in disorganized aortic elastic fibers and reduced lifespan in the heterozygous state, and causes disregulation of TGF-b signaling (Yamada et al., 2021).; In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26188975, 34456753, 29543232) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.88	D;D;.;.;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D;D;D;D;D
M_CAP	Pathogenic	0.81	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D
MetaSVM	Pathogenic	0.97	D
MutationAssessor	Pathogenic	3.7	.;H;.;.;.
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-8.3	D;D;D;D;D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D
Polyphen		1.0	.;D;.;.;.
Vest4		0.86, 0.85, 0.86
MutPred		0.88		.;Loss of disorder (P = 0.0434);.;.;.;
MVP		0.98
MPC		1.6
ClinPred		1.0	D
GERP RS		6.0
Varity_R		0.99
gMVP		0.89

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1554699638; hg19: chr9-101895010;