chr3-48584742-C-A
Variant summary
Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM5PP3_StrongPP5_Very_Strong
The NM_000094.4(COL7A1):c.4039G>T(p.Gly1347Trp) variant causes a missense change. The variant allele was found at a frequency of 0.00000682 in 1,613,896 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. 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. G1347R) has been classified as Pathogenic.
Frequency
Consequence
NM_000094.4 missense
Scores
Clinical Significance
Conservation
Publications
- epidermolysis bullosa with congenital localized absence of skin and deformity of nailsInheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
- dystrophic epidermolysis bullosa pruriginosaInheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet
- recessive dystrophic epidermolysis bullosaInheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Orphanet, Genomics England PanelApp, Ambry Genetics, G2P, ClinGen
- generalized dominant dystrophic epidermolysis bullosaInheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia, Orphanet
- pretibial dystrophic epidermolysis bullosaInheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
- transient bullous dermolysis of the newbornInheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
- acral dystrophic epidermolysis bullosaInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- dystrophic epidermolysis bullosa, nails onlyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- recessive dystrophic epidermolysis bullosa inversaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- recessive dystrophic epidermolysis bullosa-generalized otherInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Pathogenic. The variant received 14 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt | 
|---|---|---|---|---|---|---|---|---|---|---|
| COL7A1 | ENST00000681320.1 | c.4039G>T | p.Gly1347Trp | missense_variant | Exon 35 of 119 | NM_000094.4 | ENSP00000506558.1 | |||
| COL7A1 | ENST00000328333.12 | c.4039G>T | p.Gly1347Trp | missense_variant | Exon 34 of 118 | 1 | ENSP00000332371.8 | |||
| COL7A1 | ENST00000487017.5 | n.-222G>T | upstream_gene_variant | 5 | 
Frequencies
GnomAD3 genomes  0.00000657  AC: 1AN: 152188Hom.:  0  Cov.: 32 show subpopulations 
GnomAD2 exomes  AF:  0.00000398  AC: 1AN: 251024 AF XY:  0.00   show subpopulations 
GnomAD4 exome  AF:  0.00000684  AC: 10AN: 1461708Hom.:  1  Cov.: 35 AF XY:  0.00000963  AC XY: 7AN XY: 727158 show subpopulations 
Age Distribution
GnomAD4 genome  0.00000657  AC: 1AN: 152188Hom.:  0  Cov.: 32 AF XY:  0.00  AC XY: 0AN XY: 74350 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
Recessive dystrophic epidermolysis bullosa    Pathogenic:2 
This sequence change is predicted to replace glycine with tryptophan at codon 1347 of the COL7A1 protein (p.(Gly1347Trp)). The glycine residue is evolutionarily conserved (invariant in 100 vertebrates, UCSC), and is located in a Gly-X-Y repeat in the collagen triple helical region (PM1). There is a large physicochemical difference between glycine and tryptophan. The variant is present in a single individual in a large population cohort (PM2; 1/251,024 alleles in gnomAD v2.1). The variant has been identified with a second pathogenic allele in at least four cases with recessive dystrophic epidermolysis bullosa (PM3_Strong; PMID: 18565177, 21113014, 21382783, 26707537). Multiple lines of computational evidence predict a deleterious effect for the missense substitution (PP3; 6/6 algorithms). A similar pathogenic missense change involving the glycine (p.Gly1347Arg) at this position has been seen before (PM5; ClinVar). Based on the classification scheme RMH ACMG Guidelines v1.2.1, this variant is classified as PATHOGENIC. Following criteria are met: PM3_Strong, PM1, PM2, PM5, PP3. -
Variant summary: COL7A1 c.4039G>T (p.Gly1347Trp) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251024 control chromosomes. c.4039G>T has been reported in the literature in individuals affected with Dystrophic Epidermolysis Bullosa, Recessive (Kern_2006, Schumann_2008, vandenAkker_2011, Kopeckova_2016). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 16484981, 18565177, 21113014, 34826142, 21382783, 26707537). ClinVar contains an entry for this variant (Variation ID: 937822). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
not provided    Pathogenic:1 
This sequence change replaces glycine, which is neutral and non-polar, with tryptophan, which is neutral and slightly polar, at codon 1347 of the COL7A1 protein (p.Gly1347Trp). This variant is present in population databases (rs121912833, gnomAD 0.007%). This missense change has been observed in individuals with autosomal recessive dystrophic epidermolysis bullosa (PMID: 16484981, 18565177, 21113014). ClinVar contains an entry for this variant (Variation ID: 937822). 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 COL7A1 protein function with a positive predictive value of 95%. This variant disrupts the triple helix domain of COL7A1. 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), and variants at these glycine residues in COL7A1 are more frequently observed in individuals with disease than in the general population (PMID: 22058051). However, the clinical significance of this observation remains uncertain since only a limited number of affected individuals have been described to date. For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at