rs863223834

Variant names:

• chr9-99144735-A-G
• rs863223834
• NM_004612.4:c.977A>G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP2 PP3

The NM_004612.4(TGFBR1):​c.977A>G​(p.Lys326Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,218 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: TGFBR1 NM_004612.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 9.31

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 6 ACMG points.

• PM1: In a domain Protein kinase (size 290) in uniprot entity TGFR1_HUMAN there are 34 pathogenic changes around while only 2 benign (94%) in NM_004612.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the TGFBR1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 48 curated pathogenic missense variants (we use a threshold of 10). The gene has 16 curated benign missense variants. Gene score misZ: 2.7935 (below the threshold of 3.09). Trascript score misZ: 3.6468 (above the threshold of 3.09). GenCC associations: The gene is linked to 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, 0.833

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TGFBR1	NM_004612.4	c.977A>G	p.Lys326Arg	missense_variant	Exon 6 of 9	ENST00000374994.9	NP_004603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TGFBR1	ENST00000374994.9	c.977A>G	p.Lys326Arg	missense_variant	Exon 6 of 9	1	NM_004612.4	ENSP00000364133.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152218 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152218 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74366

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Familial thoracic aortic aneurysm and aortic dissection Uncertain:2

Jul 06, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.K326R variant (also known as c.977A>G), located in coding exon 6 of the TGFBR1 gene, results from an A to G substitution at nucleotide position 977. The lysine at codon 326 is replaced by arginine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Apr 30, 2022

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TGFBR1 protein function. ClinVar contains an entry for this variant (Variation ID: 213902). This missense change has been observed in individual(s) with clinical features of TGFBR1-related conditions (Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 326 of the TGFBR1 protein (p.Lys326Arg). -

not provided Uncertain:1

Jul 13, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Has not been previously published as pathogenic or benign to our knowledge; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.44	T;.;.;.
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D;D;D
M_CAP	Pathogenic	0.42	D
MetaRNN	Pathogenic	0.83	D;D;D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Uncertain	2.1	M;.;.;.
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-2.9	D;D;D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	D;D;D;D
Sift4G	Uncertain	0.0050	D;D;D;D
Polyphen		1.0	D;D;.;.
Vest4		0.71
MutPred		0.77		Loss of ubiquitination at K326 (P = 0.0218);.;.;.;
MVP		0.93
MPC		1.4
ClinPred		0.98	D
GERP RS		5.6
Varity_R		0.96
gMVP		0.48

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.13		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: rs863223834; hg19: chr9-101907017;