NM_000494.4:c.*8A>G

Variant names:

• chr10-104032227-T-C
• rs149754696
• NM_000494.4:c.*8A>G

Variant summary

Our verdict is Benign. The variant received -14 ACMG points: 0P and 14B. BP4_Strong BP6_Moderate BS1 BS2

The NM_000494.4(COL17A1):​c.*8A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000277 in 1,612,218 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0015 (2 hom., cov: 33)
  • Exomes 𝑓: 0.00015 (0 hom.)
• Consequence: COL17A1 NM_000494.4 3_prime_UTR
• Clinical Significance: Likely benign criteria provided, single submitter B:2
• Conservation: PhyloP100: -0.680
• Publications: 0 publications found

Genes affected

COL17A1 (HGNC:2194): (collagen type XVII alpha 1 chain) This gene encodes the alpha chain of type XVII collagen. Unlike most collagens, collagen XVII is a transmembrane protein. Collagen XVII is a structural component of hemidesmosomes, multiprotein complexes at the dermal-epidermal basement membrane zone that mediate adhesion of keratinocytes to the underlying membrane. Mutations in this gene are associated with both generalized atrophic benign and junctional epidermolysis bullosa. Two homotrimeric forms of type XVII collagen exist. The full length form is the transmembrane protein. A soluble form, referred to as either ectodomain or LAD-1, is generated by proteolytic processing of the full length form. [provided by RefSeq, Jul 2008]

COL17A1 Gene-Disease associations (from GenCC):

• epithelial recurrent erosion dystrophy

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae), PanelApp Australia
• epidermolysis bullosa, junctional 4, intermediate

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P, Ambry Genetics
• junctional epidermolysis bullosa, non-Herlitz type

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• amelogenesis imperfecta

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• generalized junctional epidermolysis bullosa non-Herlitz type

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• late-onset junctional epidermolysis bullosa

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• localized junctional epidermolysis bullosa, non-Herlitz type

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Benign. The variant received -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.85).
• BP6: Variant 10-104032227-T-C is Benign according to our data. Variant chr10-104032227-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 298680.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00149 (227/152334) while in subpopulation AFR AF = 0.00527 (219/41580). AF 95% confidence interval is 0.0047. There are 2 homozygotes in GnomAd4. There are 104 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
• BS2: High Homozygotes in GnomAd4 at 2 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL17A1	NM_000494.4	c.*8A>G		3_prime_UTR_variant	Exon 56 of 56	ENST00000648076.2	NP_000485.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL17A1	ENST00000648076.2	c.*8A>G		3_prime_UTR_variant	Exon 56 of 56		NM_000494.4	ENSP00000497653.1

Frequencies

GnomAD3 genomes AF: 0.00148 AC: 226 AN: 152216 Hom.: 2 Cov.: 33

Gnomad AFR AF: 0.00526

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000262

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00144

GnomAD2 exomes AF: 0.000386 AC: 97 AN: 251386 AF XY: 0.000309

Gnomad AFR exome AF: 0.00517

Gnomad AMR exome AF: 0.000202

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000352

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.000150 AC: 219 AN: 1459884 Hom.: 0 Cov.: 30 AF XY: 0.000105 AC XY: 76 AN XY: 726326

African (AFR) AF: 0.00556 AC: 186 AN: 33442

American (AMR) AF: 0.000313 AC: 14 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86226

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53398

Middle Eastern (MID) AF: 0.000347 AC: 2 AN: 5768

European-Non Finnish (NFE) AF: 0.00000540 AC: 6 AN: 1110208

Other (OTH) AF: 0.000182 AC: 11 AN: 60304

GnomAD4 genome AF: 0.00149 AC: 227 AN: 152334 Hom.: 2 Cov.: 33 AF XY: 0.00140 AC XY: 104 AN XY: 74506

African (AFR) AF: 0.00527 AC: 219 AN: 41580

American (AMR) AF: 0.000261 AC: 4 AN: 15304

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68014

Other (OTH) AF: 0.00142 AC: 3 AN: 2112

Alfa AF: 0.00131 Hom.: 0

Bravo AF: 0.00166

Asia WGS AF: 0.000866 AC: 3 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, single submitter

Submissions by phenotype

Junctional epidermolysis bullosa, non-Herlitz type Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

COL17A1-related disorder Benign:1

Oct 28, 2019

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.85
CADD	Benign	1.3
DANN	Benign	0.44
PhyloP100		-0.68
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs149754696; hg19: chr10-105791985;