NM_000358.3:c.1663C>T
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong
The NM_000358.3(TGFBI):c.1663C>T(p.Arg555Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,608 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R555Q) has been classified as Pathogenic.
Frequency
Consequence
NM_000358.3 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
TGFBI | NM_000358.3 | c.1663C>T | p.Arg555Trp | missense_variant | Exon 12 of 17 | ENST00000442011.7 | NP_000349.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152138Hom.: 0 Cov.: 32
GnomAD4 exome AF: 0.00000137 AC: 2AN: 1461470Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 727014
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152138Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74316
ClinVar
Submissions by phenotype
not provided Pathogenic:3
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 555 of the TGFBI protein (p.Arg555Trp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with autosomal dominant corneal dystrophy (PMID: 1264234, 9054935, 11923233, 21264234). It has also been observed to segregate with disease in related individuals. This variant is also known as 1710C>T. ClinVar contains an entry for this variant (Variation ID: 7866). 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 TGFBI protein function with a negative predictive value of 80%. Experimental studies have shown that this missense change affects TGFBI function (PMID: 23559853). This variant disrupts the p.Arg555 amino acid residue in TGFBI. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 21135107, 22355247). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
TGFBI: PP1:Strong, PM2, PM5, PM6, PS4:Moderate, BP4 -
Published functional studies demonstrate that p.(R555W) leads to increased expression and aggregation of the TGFBI protein (Runager et al., 2011; Yam et al., 2012; Underhaug et al., 2013); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 16087849, 23828476, 19948560, 19337156, 23991378, 21836353, 22355247, 20664689, 21264234, 16767671, 22746317, 22575305, 23559853, 9054935, 12709742, 26305369, 26464103, 18650671, 9744382, 30915236, 34097874, 14576527, 16118514, 22605926, 11923233, 21135107, 24129074, 22850414, 35985662, 33816482, 9727509) -
Groenouw corneal dystrophy type I Pathogenic:2
- -
- -
Lattice corneal dystrophy Type I Pathogenic:1
- -
Reis-Bucklers' corneal dystrophy;C0521723:Epithelial basement membrane dystrophy;C1275685:Avellino corneal dystrophy;C1562894:Thiel-Behnke corneal dystrophy;C1641846:Groenouw corneal dystrophy type I;C1690006:Lattice corneal dystrophy Type I;C1837974:Corneal dystrophy, lattice type 3A Pathogenic:1
The de novo c.1663C>T (p.Arg555Trp) variant identified in the TGFBI gene substitutes an Arginine for Tryptophan at amino acid 555/684 (exon12/17). This amino acid is not well conserved in mammals. This variant is found with low frequency in gnomAD(v3.1.1) (1 heterozygote, 0 homozygotes; allele frequency:6.57e-6) suggesting it is not a common benign variant in the populations represented in that database. In silico algorithms predict this variant to be Damaging (SIFT;score:0.018) and Pathogenic (REVEL; score:0.6399) to the function of the canonical transcript. This variant is reported as Pathogenic in ClinVar (VarID:7866), and has been reported in many individuals in the literature with corneal dystrophy, and is a well-known pathogenic variant associated with corneal dystrophy [PMID:33816482; PMID:33513810; others]. The de novo c.1663C>T (p.Arg555Trp) variant identified in the TGFBI gene is reported as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at