rs764028978

Positions:

• chr1-218434160-G-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PP3 BS2

The ENST00000366930.9(TGFB2):​c.589G>A​(p.Glu197Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,461,866 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: not found (cov: 32)
  • Exomes 𝑓: 0.000019 (0 hom.)
• Consequence: TGFB2 ENST00000366930.9 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 7.54

Genes affected

TGFB2 (HGNC:11768): (transforming growth factor beta 2) This gene encodes a secreted ligand of the TGF-beta (transforming growth factor-beta) superfamily of proteins. Ligands of this family bind various TGF-beta receptors leading to recruitment and activation of SMAD family transcription factors that regulate gene expression. The encoded preproprotein is proteolytically processed to generate a latency-associated peptide (LAP) and a mature peptide, and is found in either a latent form composed of a mature peptide homodimer, a LAP homodimer, and a latent TGF-beta binding protein, or in an active form consisting solely of the mature peptide homodimer. The mature peptide may also form heterodimers with other TGF-beta family members. Disruption of the TGF-beta/SMAD pathway has been implicated in a variety of human cancers. A chromosomal translocation that includes this gene is associated with Peters' anomaly, a congenital defect of the anterior chamber of the eye. Mutations in this gene may be associated with Loeys-Dietz syndrome. This gene encodes multiple isoforms that may undergo similar proteolytic processing. [provided by RefSeq, Aug 2016]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.803
• BS2: High AC in GnomAdExome4 at 28 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TGFB2	NM_003238.6	c.589G>A	p.Glu197Lys	missense_variant	3/7	ENST00000366930.9	NP_003229.1
TGFB2	NM_001135599.4	c.673G>A	p.Glu225Lys	missense_variant	4/8		NP_001129071.1
TGFB2	NR_138148.2	n.1955G>A		non_coding_transcript_exon_variant	3/7
TGFB2	NR_138149.2	n.2039G>A		non_coding_transcript_exon_variant	4/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TGFB2	ENST00000366930.9	c.589G>A	p.Glu197Lys	missense_variant	3/7	1	NM_003238.6	ENSP00000355897	P1
TGFB2	ENST00000366929.4	c.673G>A	p.Glu225Lys	missense_variant	4/8	1		ENSP00000355896
TGFB2	ENST00000479322.1	n.35G>A		non_coding_transcript_exon_variant	1/5	3
TGFB2	ENST00000488793.1	n.253G>A		non_coding_transcript_exon_variant	3/3	3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251248 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135782

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000192 AC: 28 AN: 1461866 Hom.: 0 Cov.: 31 AF XY: 0.0000234 AC XY: 17 AN XY: 727236

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000207

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Loeys-Dietz syndrome 4 Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Victorian Clinical Genetics Services, Murdoch Childrens Research Institute	Mar 31, 2022	Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3B. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with Loeys-Dietz syndrome 4 (MIM#614816). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from glutamic acid to lysine. (I) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD (v2) <0.001 for a dominant condition (2 heterozygotes, 0 homozygotes). (SP) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0600 - Variant is located in the annotated TGF-beta propeptide domain (DECIPHER). (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0809 - Previous evidence of pathogenicity for this variant is inconclusive. This variant has been reported twice as a VUS (ClinVar). (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 16, 2024	This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 197 of the TGFB2 protein (p.Glu197Lys). This variant is present in population databases (rs764028978, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with TGFB2-related conditions. ClinVar contains an entry for this variant (Variation ID: 295490). 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 not expected to disrupt TGFB2 protein function with a negative predictive value of 95%. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Familial thoracic aortic aneurysm and aortic dissection Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 29, 2021

The p.E197K variant (also known as c.589G>A), located in coding exon 3 of the TGFB2 gene, results from a G to A substitution at nucleotide position 589. The glutamic acid at codon 197 is replaced by lysine, an amino acid with similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.68
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.12
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.47	T;.
Eigen	Pathogenic	0.71
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Benign	0.020	T
MetaRNN	Pathogenic	0.80	D;D
MetaSVM	Benign	-0.50	T
MutationAssessor	Benign	1.7	L;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.80	T
PROVEAN	Benign	-0.98	N;N
REVEL	Uncertain	0.33
Sift	Uncertain	0.0050	D;D
Sift4G	Benign	0.32	T;T
Polyphen		0.99	D;D
Vest4		0.75
MutPred		0.58		Gain of MoRF binding (P = 0.0141);.;
MVP		0.87
MPC		1.2
ClinPred		0.71	D
GERP RS		5.9
Varity_R		0.30
gMVP		0.68

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: rs764028978; hg19: chr1-218607502;