rs121912833

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

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000068 ( 1 hom. )

Consequence

COL7A1
NM_000094.4 missense

Scores

15
2
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 5.57

Publications

6 publications found
Variant links:
Genes affected
COL7A1 (HGNC:2214): (collagen type VII alpha 1 chain) This gene encodes the alpha chain of type VII collagen. The type VII collagen fibril, composed of three identical alpha collagen chains, is restricted to the basement zone beneath stratified squamous epithelia. It functions as an anchoring fibril between the external epithelia and the underlying stroma. Mutations in this gene are associated with all forms of dystrophic epidermolysis bullosa. In the absence of mutations, however, an acquired form of this disease can result from an autoimmune response made to type VII collagen. [provided by RefSeq, Jul 2008]
COL7A1 Gene-Disease associations (from GenCC):
  • epidermolysis bullosa with congenital localized absence of skin and deformity of nails
    Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • dystrophic epidermolysis bullosa pruriginosa
    Inheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet
  • recessive dystrophic epidermolysis bullosa
    Inheritance: AR, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Orphanet, Genomics England PanelApp, Ambry Genetics, G2P, ClinGen
  • generalized dominant dystrophic epidermolysis bullosa
    Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia, Orphanet
  • pretibial dystrophic epidermolysis bullosa
    Inheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
  • transient bullous dermolysis of the newborn
    Inheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
  • acral dystrophic epidermolysis bullosa
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • dystrophic epidermolysis bullosa, nails only
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • recessive dystrophic epidermolysis bullosa inversa
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • recessive dystrophic epidermolysis bullosa-generalized other
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 ACMG points.

PM5
Other missense variant is known to change same aminoacid residue: Variant chr3-48584742-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 17434.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.973
PP5
Variant 3-48584742-C-A is Pathogenic according to our data. Variant chr3-48584742-C-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 937822.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL7A1NM_000094.4 linkc.4039G>T p.Gly1347Trp missense_variant Exon 35 of 119 ENST00000681320.1 NP_000085.1 Q02388-1Q59F16

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
COL7A1ENST00000681320.1 linkc.4039G>T p.Gly1347Trp missense_variant Exon 35 of 119 NM_000094.4 ENSP00000506558.1 Q02388-1
COL7A1ENST00000328333.12 linkc.4039G>T p.Gly1347Trp missense_variant Exon 34 of 118 1 ENSP00000332371.8 Q02388-1
COL7A1ENST00000487017.5 linkn.-222G>T upstream_gene_variant 5

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152188
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251024
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.0000618
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000684
AC:
10
AN:
1461708
Hom.:
1
Cov.:
35
AF XY:
0.00000963
AC XY:
7
AN XY:
727158
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000927
AC:
8
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53250
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112002
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152188
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74350
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000226
Hom.:
0
Bravo
AF:
0.0000453
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Recessive dystrophic epidermolysis bullosa Pathogenic:2
Mar 30, 2023
Molecular Genetics, Royal Melbourne Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. -

Sep 09, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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
Feb 17, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.89
BayesDel_addAF
Pathogenic
0.41
D
BayesDel_noAF
Pathogenic
0.53
CADD
Pathogenic
32
DANN
Benign
0.97
DEOGEN2
Pathogenic
0.93
D
Eigen
Pathogenic
0.90
Eigen_PC
Pathogenic
0.80
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Pathogenic
0.45
D
MetaRNN
Pathogenic
0.97
D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
4.1
H
PhyloP100
5.6
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-6.6
D
REVEL
Pathogenic
0.94
Sift
Uncertain
0.0010
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.89
MVP
0.82
MPC
0.29
ClinPred
1.0
D
GERP RS
5.3
Varity_R
0.97
gMVP
1.0
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
Splicevardb
2.0
SpliceAI score (max)
0.020
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs121912833; hg19: chr3-48622175; API