3-48582615-AC-GT

Variant names:

• chr3-48582615-AC-GT
• NM_000094.4:c.4556_4557delGTinsAC
• COL7A1 p.Gly1519Asp

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PS1 PM1 PM5

The NM_000094.4(COL7A1):​c.4556_4557delGTinsAC​(p.Gly1519Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1519S) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL7A1 NM_000094.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.697
• Publications: 0 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: Likely_pathogenic. The variant received 8 ACMG points.

• PS1: Transcript NM_000094.4 (COL7A1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 7 uncertain in NM_000094.4
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-48582617-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 3251729.

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.4556_4557delGTinsAC	p.Gly1519Asp	missense	N/A	NP_000085.1	Q02388-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL7A1	ENST00000681320.1	MANE Select	c.4556_4557delGTinsAC	p.Gly1519Asp	missense	N/A	ENSP00000506558.1	Q02388-1
	COL7A1	ENST00000328333.12	TSL:1	c.4556_4557delGTinsAC	p.Gly1519Asp	missense	N/A	ENSP00000332371.8	Q02388-1
	COL7A1	ENST00000487017.5	TSL:5	n.473_474delGTinsAC		non_coding_transcript_exon	Exon 10 of 83

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.70

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr3-48620048;