Junctional Epidermolysis Bullosa via the COL17A1 Gene

Summary and Pricing

Test Method

Exome Sequencing with CNV Detection
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
7983 COL17A1 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
7983COL17A181479 81479(x2) $890 Order Options and Pricing

Pricing Comments

Our favored testing approach is exome based NextGen sequencing with CNV analysis. This will allow cost effective reflexing to PGxome or other exome based tests. However, if full gene Sanger sequencing is desired for STAT turnaround time, insurance, or other reasons, please see link below for Test Code, pricing, and turnaround time information. If the Sanger option is selected, CNV detection may be ordered through Test #600.

An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.

Click here for costs to reflex to whole PGxome (if original test is on PGxome Sequencing backbone).

Click here for costs to reflex to whole PGnome (if original test is on PGnome Sequencing backbone).

The Sanger Sequencing method for this test is NY State approved.

For Sanger Sequencing click here.

Turnaround Time

18 days on average for standard orders or 13 days on average for STAT orders.

Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.

Targeted Testing

For ordering sequencing of targeted known variants, go to our Targeted Variants page.

EMAIL CONTACTS

Genetic Counselors

Geneticist

  • Stela Berisha, PhD, FACMG

Clinical Features and Genetics

Clinical Features

The collagen protein XVII (also known as BP180 and BPAG2) encoded by COL17A1 is essential for cohesion between dermal-epidermal junction, as it is a key component of hemidesmosomes needed to hold stratified epithelia to the basal membrane. Junctional epidermolysis bullosa (JEB), one of the four major types of epidermolysis bullosa (EB), is a clinically and genetically heterogeneous skin/mucosa separation disorder characterized by blister formation induced by mild trauma. COL17A1 variants often cause the mild type of JEB (non-Herlitz JEB, OMIM 226650); however, in some cases, COL17A1 null variants were also reported in the neonatal lethal form (Herlitz JEB, OMIM 226700). Variki et al. studied 20 cases with COL17A1 variants; seven of them had generalized blisters, hematuria, anemia, and growth retardation, and one of the seven patients had pseudosyndactly and wrist/ankle abnormalities, which mimic the features of dystrophic epidermolysis bullosa (Varki et al. J Med Genet 43:641-652, 2006). Other common clinical features in JEB are enamel defects, nail dystrophy, and alopecia. It should be noted that clinical manifestations overlap significantly among different types of EB, because at least 12 other genes encoding the multiprotein cohesion complex in skin contribute to epidemolysis bullosa (EB; Fine et al. J Am Acad Derm 58:931-950, 2008; Laimer et al. Dermatol Clin 28:55-60, 2010). Therefore, patients with clinically-suspected EB can be evaluated by skin biopsy to help with clinical diagnosis and direct genetic testing.

Genetics

Junctional epidermolysis bullosa (JEB) is an autosomal recessive disorder caused by variants in LAMA3, LAMB3, LAMC2, and COL17A1. Variants in COL17A1 account for ~12% of reported pathogenic variants related to JEB (Pfendner et al. GeneReviews, 2008). Collagen XVII, a transmembrane protein of the hemidesmosome, contains an intracellular noncollagenous domain (exons 2 to 17), and an extracellular collagenous domain (exons 18 to 56; Giudice et al. J Invest Dermatol 99:243-250,1992; McGrath et al. Nat Genet 11:83-86, 1995; Gatalica et al. Am. J. Hum. Genet 60:352-365, 1997, Varki et al. 2006, Pfendner et al. GeneReviews, 2008). Most known variants (>80%) result in truncated proteins (nonsense, small deletions/insertions, and splicing). Two recurring variants (p.Gly803* and p.Arg1226*) comprise 7% and 10% of the reported COL17A1 variants, respectively (Kiritsi et al. J Med Genet 48:450-457, 2011). A heterozygous variant c.1880G>T (p.G627V) in COL17A1 was reported in an autosomal dominant JEB patient with an enamel defect (Almaani et al. Br J Dermatol 160:1094-1097, 2009). Variants in COL17A1 were also identified in a patient affected with epidermolysis bullosa simplex (Pasmooij et al. Br J Dermatol 151:669-674, 2004).

Clinical Sensitivity - Sequencing with CNV PGxome

One study reported that the COL17A1 gene variants were found in 98.8% (85/86 alleles) of the 43 JEB patients with either reduced or absent collagen XVII expression (Kiritsi et al. J Med Genet 48:450-457, 2011).

Testing Strategy

This test provides full coverage of all coding exons of the COL17A1 gene plus 10 bases of flanking noncoding DNA in all available transcripts along with other non-coding regions in which pathogenic variants have been identified at PreventionGenetics or reported elsewhere. We define full coverage as >20X NGS reads or Sanger sequencing. PGnome panels typically provide slightly increased coverage over the PGxome equivalent. PGnome sequencing panels have the added benefit of additional analysis and reporting of deep intronic regions (where applicable).

Dependent on the sequencing backbone selected for this testing, discounted reflex testing to any other similar backbone-based test is available (i.e., PGxome panel to whole PGxome; PGnome panel to whole PGnome).

Indications for Test

Individuals with clinical features consistent with H-JEB, non-Herlitz JEB. Individuals diagnosed with skin biopsy showing absent or reduced collagen XVII expression are preferred. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in COL17A1.

Gene

Official Gene Symbol OMIM ID
COL17A1 113811
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Non-Herlitz Junctional Epidermolysis Bullosa AR 226650

Related Tests

Name
Amelogenesis Imperfecta Panel
Ectodermal Dysplasia/Skin Fragility Syndrome via the PKP1 Gene
Epidermolysis Bullosa Simplex (EBS) via the KRT14 Gene
Epidermolysis Bullosa Simplex (EBS) via the KRT5 Gene
Epidermolysis Bullosa with Pyloric Atresia via the ITGA6 Gene

Citations

  • Almaani et al. Autosomal dominant junctional epidermolysis bullosa. Br J Dermatol 160(5):1094-1097, 2009. PubMed ID: 19120338
  • Fine et al. (2008). PubMed ID: 18374450
  • Gatalica et al. Cloning of the human type XVII collagen gene (COL17A1), and detection of novel mutations in generalized atrophic benign epidermolysis bullosa. Am J Hum Genet 60(2):352-365, 1997. PubMed ID: 9012408
  • Giudice et al. Cloning and primary structural analysis of the bullous pemphigoid autoantigen BP180. J Invest Dermatol 99(3):243-250, 1992. PubMed ID: 1324962
  • Kiritsi et al. Molecular mechanisms of phenotypic variability in junctional epidermolysis bullosa. J Med Genet 48(7):450-457, 2011. PubMed ID: 21357940
  • Laimer et al. Herlitz junctional epidermolysis bullosa. Dermatol Clin 28(1):55-60, 2010. PubMed ID: 19945616
  • McGrath et al. Mutations in the 180-kD bullous pemphigoid antigen (BPAG2), a hemidesmosomal transmembrane collagen (COL17A1), in generalized atrophic benign epidermolysis bullosa. Nat Genet 11(1):83-86, 1995. PubMed ID: 7550320
  • Pasmooij et al.  Features of epidermolysis bullosa simplex due to mutations in the ectodomain of type XVII collagen. Br J Dermatol 151(3):669-674, 2004. PubMed ID: 15377356
  • Pfendner et al. Junctional Epidermolysis Bullosa. GeneReviews, 2008 PubMed ID: 20301304
  • Varki, et al. Epidermolysis bullosa. II. (2007). PubMed ID: 16971478

Ordering/Specimens

Ordering Options

We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.

myPrevent - Online Ordering

  • The test can be added to your online orders in the Summary and Pricing section.
  • Once the test has been added log in to myPrevent to fill out an online requisition form.
  • PGnome sequencing panels can be ordered via the myPrevent portal only at this time.

Requisition Form

  • A completed requisition form must accompany all specimens.
  • Billing information along with specimen and shipping instructions are within the requisition form.
  • All testing must be ordered by a qualified healthcare provider.

For Requisition Forms, visit our Forms page


Specimen Types

Specimen Requirements and Shipping Details

PGxome (Exome) Sequencing Panel

PGnome (Genome) Sequencing Panel

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ORDER OPTIONS

View Ordering Instructions

1) Select Test Method (Backbone)


1) Select Test Type


2) Select Additional Test Options

STAT and Prenatal Test Options are not available with Patient Plus.

No Additional Test Options are available for this test.

Note: acceptable specimen types are whole blood and DNA from whole blood only.
Total Price: $
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