3-48593554-G-A

Variant names:

• chr3-48593554-G-A
• rs1203706188
• NM_000094.4:c.409C>T

Variant summary

Our verdict is Pathogenic. The variant received 20 ACMG points: 20P and 0B. PVS1 PS3 PP5_Very_Strong

The NM_000094.4(COL7A1):​c.409C>T​(p.Arg137*) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000041 in 1,461,870 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 (★★). ClinVar reports functional evidence for this variant: "SCV000617662: However, a therapeutic study of aminoglycoside treatment on cells transfected with R137X improved readthrough and resulted in some synthesis and secretion of a stable full-length collagen VII protein (Cogan et al., 2014).". Synonymous variant affecting the same amino acid position (i.e. R137R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: COL7A1 NM_000094.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 6.02
• Publications: 1 publications found

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: 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: Ambry Genetics, G2P, Orphanet, Genomics England PanelApp, ClinGen
• generalized dominant dystrophic epidermolysis bullosa

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• pretibial dystrophic epidermolysis bullosa

  Inheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
• transient bullous dermolysis of the newborn

  Inheritance: AR, AD Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet
• 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

ACMG classification

Our verdict: Pathogenic. The variant received 20 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV000617662: However, a therapeutic study of aminoglycoside treatment on cells transfected with R137X improved readthrough and resulted in some synthesis and secretion of a stable full-length collagen VII protein (Cogan et al., 2014).
• PP5: Variant 3-48593554-G-A is Pathogenic according to our data. Variant chr3-48593554-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 449472.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000094.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL7A1	NM_000094.4	MANE Select	c.409C>T	p.Arg137*	stop_gained	Exon 4 of 119	NP_000085.1	Q02388-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL7A1	ENST00000681320.1	MANE Select	c.409C>T	p.Arg137*	stop_gained	Exon 4 of 119	ENSP00000506558.1	Q02388-1
	COL7A1	ENST00000328333.12	TSL:1	c.409C>T	p.Arg137*	stop_gained	Exon 3 of 118	ENSP00000332371.8	Q02388-1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461870 Hom.: 0 Cov.: 35 AF XY: 0.00000550 AC XY: 4 AN XY: 727230

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1112008

Other (OTH) AF: 0.0000166 AC: 1 AN: 60394

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
3	-	-	not provided (3)
1	-	-	Epidermolysis bullosa dystrophica (1)
1	-	-	Recessive dystrophic epidermolysis bullosa (1)
1	-	-	Recessive dystrophic epidermolysis bullosa;C0268371:Dominant dystrophic epidermolysis bullosa with absence of skin;C0432321:Pretibial dystrophic epidermolysis bullosa;C0432322:Generalized dominant dystrophic epidermolysis bullosa;C1275114:Epidermolysis bullosa pruriginosa;C1843761:Nonsyndromic congenital nail disorder 8;C1851573:Transient bullous dermolysis of the newborn (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Uncertain	0.93	D
PhyloP100		6.0
Vest4		0.65
GERP RS		4.5
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1203706188; hg19: chr3-48630987;