14-75963445-C-T
Variant summary
Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_StrongBS1_SupportingBS2
The NM_003239.5(TGFB3):c.797G>A(p.Arg266His) variant causes a missense change. The variant allele was found at a frequency of 0.0000496 in 1,614,140 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_003239.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Benign. Variant got -9 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
TGFB3 | NM_003239.5 | c.797G>A | p.Arg266His | missense_variant | Exon 5 of 7 | ENST00000238682.8 | NP_003230.1 | |
TGFB3 | NM_001329939.2 | c.797G>A | p.Arg266His | missense_variant | Exon 6 of 8 | NP_001316868.1 | ||
TGFB3 | NM_001329938.2 | c.797G>A | p.Arg266His | missense_variant | Exon 5 of 5 | NP_001316867.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000125 AC: 19AN: 152130Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000994 AC: 25AN: 251432Hom.: 0 AF XY: 0.000103 AC XY: 14AN XY: 135884
GnomAD4 exome AF: 0.0000410 AC: 60AN: 1461892Hom.: 0 Cov.: 32 AF XY: 0.0000440 AC XY: 32AN XY: 727246
GnomAD4 genome AF: 0.000131 AC: 20AN: 152248Hom.: 0 Cov.: 32 AF XY: 0.000148 AC XY: 11AN XY: 74456
ClinVar
Submissions by phenotype
not specified Uncertain:2
A variant of uncertain significance has been identified in the TGFB3 gene. The R266H variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. It was not observed with any significant frequency in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Although the R266H substitution occurs at a position that is conserved through mammals, R266H is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. Finally, in silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function -
Variant summary: TGFB3 c.797G>A (p.Arg266His) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 9.9e-05 in 251432 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.797G>A has been reported in the literature in an individual affected with with thoracic aortic disease without strong evidence for causality (Overwater_2018). This report does not provide unequivocal conclusions about association of the variant with Loeys-Dietz Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three submitters have provided clinical-significance assessments for this variant to ClinVar after 2014, and all laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Familial thoracic aortic aneurysm and aortic dissection Uncertain:1
The p.R266H variant (also known as c.797G>A), located in coding exon 5 of the TGFB3 gene, results from a G to A substitution at nucleotide position 797. The arginine at codon 266 is replaced by histidine, an amino acid with highly similar properties. This variant was detected in one individual with dilated aortic root, pectus deformity, and soft skin (Overwater E et al. Hum Mutat, 2018 09;39:1173-1192). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Rienhoff syndrome Uncertain:1
This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 266 of the TGFB3 protein (p.Arg266His). This variant is present in population databases (rs142069844, gnomAD 0.04%), and has an allele count higher than expected for a pathogenic variant. This missense change has been observed in individual(s) with TGFB3-related disease (PMID: 29907982). ClinVar contains an entry for this variant (Variation ID: 392606). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt TGFB3 protein function with a negative predictive value of 80%. 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. -
not provided Benign:1
TGFB3: BP4 -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at