rs1553507614
Variant summary
Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1PM2PM5PP2PP3PP5_Very_Strong
The NM_000090.4(COL3A1):c.953G>A(p.Gly318Asp) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 15/24 in silico tools predict a damaging outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G318S) has been classified as Likely pathogenic.
Frequency
Consequence
NM_000090.4 missense, splice_region
Scores
Clinical Significance
Conservation
Publications
- autosomal dominant Ehlers-Danlos syndrome, vascular typeInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae), Laboratory for Molecular Medicine, Genomics England PanelApp
- Ehlers-Danlos syndrome, vascular typeInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
- polymicrogyria with or without vascular-type Ehlers-Danlos syndromeInheritance: AR Classification: STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Pathogenic. The variant received 16 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| COL3A1 | ENST00000304636.9 | c.953G>A | p.Gly318Asp | missense_variant, splice_region_variant | Exon 14 of 51 | 1 | NM_000090.4 | ENSP00000304408.4 | ||
| COL3A1 | ENST00000450867.2 | c.953G>A | p.Gly318Asp | missense_variant, splice_region_variant | Exon 14 of 50 | 1 | ENSP00000415346.2 | |||
| COL3A1 | ENST00000713745.1 | c.953G>A | p.Gly318Asp | missense_variant, splice_region_variant | Exon 14 of 49 | ENSP00000519049.1 | ||||
| COL3A1 | ENST00000713744.1 | c.953G>A | p.Gly318Asp | missense_variant, splice_region_variant | Exon 14 of 49 | ENSP00000519048.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 31
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Ehlers-Danlos syndrome, type 4 Pathogenic:2
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This sequence change replaces glycine with aspartic acid at codon 318 of the COL3A1 protein (p.Gly318Asp). The glycine residue is highly conserved and there is a moderate physicochemical difference between glycine and aspartic acid. This variant is not present in population databases (ExAC no frequency). This variant has been reported in an individual affected with vascular Ehlers-Danlos syndrome (PMID: 26497932). Glycine residues within the Gly-Xaa-Yaa repeats of the triple helix domain are required for the structure and stability of fibrillar collagens (PMID: 7695699, 8218237, 19344236). In COL3A1, missense variants at these glycine residues are significantly enriched in individuals with disease (PMID: 24922459, 25758994) compared to the general population (ExAC). Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, this variant is a novel missense change affecting a residue that is known to be critical for normal protein structure, stability and function. This type of missense change is also highly enriched in affected individuals and expected to be pathogenic. However, without additional functional and/or genetic data, this variant has been classified as Likely Pathogenic. -
Familial thoracic aortic aneurysm and aortic dissection Pathogenic:1
The p.G318D variant (also known as c.953G>A), located in coding exon 14 of the COL3A1 gene, results from a G to A substitution at nucleotide position 953. The glycine at codon 318 is replaced by aspartic acid, an amino acid with similar properties. The majority (approximately two-thirds) of COL3A1 mutations identified to date have involved the substitution of another amino acid for glycine within the triple-helical domain (Pepin MG et al. Genet Med. 2014;16(12):881-8; Frank M et al. Eur J Hum Genet. 2015;23(12):1657-64). This variant was identified in one or more individuals with features consistent with vascular Ehlers-Danlos syndrome and segregated with disease in at least one family (Makrygiannis G et al. Eur J Med Genet, 2015 Nov;58:634-6; Yagyu T et al. J Am Heart Assoc, 2023 Apr;12:e028625; Ambry internal data). Internal structural analysis indicates that this alteration disrupts the characteristic G-X-Y motif in the COL3A1 protein and inserts a bulky side chain into a sterically-constrained region (Bella J et al. Science. 1994;266:75-81; Hohenester E et al. Proc. Natl. Acad. Sci. U.S.A. 2008;105:18273-7; Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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 majority of available evidence to date, this variant is likely to be pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at