rs121912849

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PM1PM5PP2PP3_ModeratePP5_Very_Strong

The NM_000094.4(COL7A1):​c.6187C>T​(p.Arg2063Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000806 in 1,613,812 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. R2063G) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

COL7A1
NM_000094.4 missense

Scores

7
5
7

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 1.01
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 15 ACMG points.

PM1
In a compositionally_biased_region Basic and acidic residues (size 17) in uniprot entity CO7A1_HUMAN there are 20 pathogenic changes around while only 0 benign (100%) in NM_000094.4
PM5
Other missense variant is known to change same aminoacid residue: Variant chr3-48575236-G-C is described in Lovd as [Pathogenic].
PP2
Missense variant in the COL7A1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 223 curated pathogenic missense variants (we use a threshold of 10). The gene has 262 curated benign missense variants. Gene score misZ: 1.5899 (below the threshold of 3.09). Trascript score misZ: 4.0428 (above the threshold of 3.09). GenCC associations: The gene is linked to recessive dystrophic epidermolysis bullosa, dystrophic epidermolysis bullosa pruriginosa, recessive dystrophic epidermolysis bullosa-generalized other, transient bullous dermolysis of the newborn, epidermolysis bullosa with congenital localized absence of skin and deformity of nails, generalized dominant dystrophic epidermolysis bullosa, dystrophic epidermolysis bullosa, nails only, acral dystrophic epidermolysis bullosa, recessive dystrophic epidermolysis bullosa inversa, pretibial dystrophic epidermolysis bullosa.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.889
PP5
Variant 3-48575236-G-A is Pathogenic according to our data. Variant chr3-48575236-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 17456.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-48575236-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
COL7A1NM_000094.4 linkc.6187C>T p.Arg2063Trp missense_variant Exon 75 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.6187C>T p.Arg2063Trp missense_variant Exon 75 of 119 NM_000094.4 ENSP00000506558.1 Q02388-1
COL7A1ENST00000328333.12 linkc.6187C>T p.Arg2063Trp missense_variant Exon 74 of 118 1 ENSP00000332371.8 Q02388-1
COL7A1ENST00000487017.5 linkn.2104C>T non_coding_transcript_exon_variant Exon 40 of 83 5

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152116
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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
GnomAD3 exomes
AF:
0.00000796
AC:
2
AN:
251234
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135868
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000821
AC:
12
AN:
1461696
Hom.:
0
Cov.:
35
AF XY:
0.0000110
AC XY:
8
AN XY:
727128
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000989
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152116
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74308
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.0000655
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Recessive dystrophic epidermolysis bullosa Pathogenic:3
-
Neuberg Centre For Genomic Medicine, NCGM
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The missense variant p.R2063W in COL7A1 (NM_000094.3) has been previously reported in affected patients (Ben Brick et al., 2014).Functional studies have demonstrated a damaging effect. The variant has been submitted to ClinVar as Pathogenic. The p.R2063W variant is observed in 2/1,13,580 (0.0018%) alleles from individuals of European (Non-Finnish) background in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. For these reasons, this variant has been classified as Pathogenic. -

Feb 01, 2008
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

Jul 03, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: COL7A1 c.6187C>T (p.Arg2063Trp) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 251234 control chromosomes. c.6187C>T has been reported in the literature in the presumed compound heterozygous, compound heterozygous, or homozygous state in multiple individuals affected with autosomal recessive Dystrophic Epidermolysis Bullosa (example, Ben Brick_2014, Chen_2023, Hovanian_1997, Jerabkova_2010), including in at least 1 individual who carried a pathogenic variant in trans. Additionally, this variant was found in the heterozygous state in several individuals affected with dystrophic epidermolysis bullosa (example, Ben Brick_2014, Cuadro-Corrales_2010, Danescu_2015, Escamez_2010, Posteraro_2005), however parental genotype/phenotype correlations were not available. These data indicate that the variant is very likely to be associated with disease. In homozygous patient samples, this variant was associated with normal transcription and protein expression levels in at least 1 study (example, Hovanian_1997), however follow up studies in patient samples heterozygous for this variant found that collagen VII protein levels were reduced and altered (data not quantified) (example, Escamez_2010, Posteraro_2005). In vitro, this variant resulted in reduced fibroblast adhesion and keratinocyte migration, as well as increased susceptibility to protease digestion (example, Woodley_2008, Woodley_2021). The following publications have been ascertained in the context of this evaluation (PMID: 24170138, 36287101, 20920254, 25201089, 20184583, 9326325, 20598510, 16271705, 27899325, 18450758, 34674926). ClinVar contains an entry for this variant (Variation ID: 17456). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:2
Nov 02, 2022
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Reported previously in the homozygous state or with a second COL7A1 variant in patients with autosomal recessive DEB (Hovnanian et al., 1997; Hashimoto et al., 1999; Gardella et al., 2002; Kern et al., 2009; Ben Brick et al., 2014; Kopeckova et al., 2016; Chen et al., 2020); Identified in unrelated patients with generalized DEB as a single heterozygous variant with no second COL7A1 variant identified (Posteraro et al., 2005; Escamez et al., 2010; Ben Brick et al., 2014; Danescu et al., 2015); Published functional studies demonstrate that this variant is located next to the helical interruption hinge region and results in local triple helix destabilization, and fibroblasts with this variant exhibit decreased motility and adhesion in vitro (Woodley et al., 2006); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 20184583, 33969388, 21448560, 12207583, 19681861, 10232406, 18558993, 16271705, 12880418, 25201089, 15115517, 18030675, 26707537, 28830826, 34426522, 24170138, 35314946, 32484238, 9326325, 18450758) -

May 02, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 2063 of the COL7A1 protein (p.Arg2063Trp). This variant is present in population databases (rs121912849, gnomAD 0.002%). This missense change has been observed in individual(s) with autosomal recessive dystrophic epidermolysis bullosa (PMID: 9326325, 12207583, 28830826). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 17456). 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%. Experimental studies have shown that this missense change affects COL7A1 function (PMID: 18450758). For these reasons, this variant has been classified as Pathogenic. -

Epidermolysis bullosa dystrophica Pathogenic:1
Oct 31, 2017
Biomedical Innovation Departament, CIEMAT
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: research

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Pathogenic
0.41
D
BayesDel_noAF
Pathogenic
0.37
CADD
Pathogenic
32
DANN
Benign
0.97
DEOGEN2
Pathogenic
0.85
D
Eigen
Benign
-0.087
Eigen_PC
Benign
-0.10
FATHMM_MKL
Benign
0.65
D
LIST_S2
Uncertain
0.88
D
M_CAP
Pathogenic
0.49
D
MetaRNN
Pathogenic
0.89
D
MetaSVM
Uncertain
0.75
D
MutationAssessor
Pathogenic
3.3
M
PrimateAI
Uncertain
0.64
T
PROVEAN
Uncertain
-3.6
D
REVEL
Pathogenic
0.65
Sift
Benign
0.045
D
Sift4G
Uncertain
0.0040
D
Polyphen
0.67
P
Vest4
0.59
MutPred
0.52
Loss of glycosylation at K2066 (P = 0.0018);
MVP
0.90
MPC
0.26
ClinPred
0.90
D
GERP RS
2.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.31
gMVP
0.94

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.050
Details are displayed if max score is > 0.2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs121912849; hg19: chr3-48612669; COSMIC: COSV60392347; COSMIC: COSV60392347; API