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Junctional Epidermolysis Bullosa via the LAMB3 Gene

Summary and Pricing

Test Method

Sequencing and CNV Detection via NextGen Sequencing using PG-Select Capture Probes
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
7723 LAMB3 81479 81479,81479 $640 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
7723LAMB381479 81479,81479 $640 Order Options and Pricing

Pricing Comments

This test is also offered via our exome backbone with CNV detection (click here). The exome-based test may be higher priced, but permits reflex to the entire exome or to any other set of clinically relevant genes.

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

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

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 minimal or no mechanical trauma. Mutations in LAMB3 contribute to ~70% of pathogenic mutations reported in JEB cases (Herlitz JEB, OMIM#226700, ~ 70% of cases and Non-Herlitz JEB, OMIM#226650, ~30% of cases) (Kiritsi et al. J Med Genet 48:450-457, 2011; Intong et al. Clin Dermatol 30:70-77, 2012). In severe cases, erosions and granulation result in restrictions in oral, corneal, esophageal and lung tissues. Patients often die during early infancy due to complications of dehydration, anemia and sepsis. 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, clinical suspected EB patients can be evaluated by electron microscopy and immunofluorescence staining to help with clinical diagnosis and direct genetic testing.

Genetics

Junctional Epidermolysis Bullosa (JEB) is an autosomal recessive disorder caused by mutations in LAMA3, LAMB3, LAMC2 and COL17A1. The LAMB3 gene codes β chain of Laminin-332 protein (also referred as Laminin5), a key component of anchoring filaments in basal membrane zone of skin required to main integrity of the skin. Most known LAMB3 mutations (>80%) resulted in prematurely terminated proteins. One study showed that the mutation c.1903C>T, p. Arg635Stop explains ~40% of mutant alleles identified in LAMB3 gene (Varki et al. J Med Genet 43:641-652, 2006). Also, ethnicity-related LAMB3 mutations were described (such as p.Arg635Stop and c.727C>T, p.Gln243Stop in Europeans, c.124C>T, p.Arg42Stop in Hispanic and African Americans). Large deletions/duplications were seen in less than 1% of cases (Varki et al. J Med Genet 43:641-652, 2006, Pfendner et al, GeneReviews, 2008). Furthermore, germline mosacism and uniparental disomy were reported (Pulkkinen and Uitto. Matrix Biol. 18:29-42, 1999; Pfendner et al. GeneReviews, 2008).

Clinical Sensitivity - Sequencing with CNV PG-Select

Detection rate should be very high in biopsy confirmed JEB patients with either reduced or absent Laminin-332 expression. As reported, LAMB3 mutations account for more than 80% of JEB related to mutations in Laminin-332 three genes and ~70% of all disease causing mutations identified in JEB.

Testing Strategy

This test provides full coverage of all coding exons of the LAMB3 gene, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.

Indications for Test

Individual with clinical features consistent with H-JEB, Non-Herlitz JEB. Individuals diagnosed with skin biopsy showing reduced or absent Luminin-332 are preferred. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in LAMB3.

Gene

Official Gene Symbol OMIM ID
LAMB3 150310
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Related Tests

Name
Amelogenesis Imperfecta Panel
Junctional Epidermolysis Bullosa via the COL17A1 Gene

Citations

  • Fine et al. (2008). PubMed ID: 18374450
  • Intong and Murrell. (2012).  PubMed ID: 22137229
  • 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
  • Pfendner et al. Junctional Epidermolysis Bullosa. GeneReviews, 2008 PubMed ID: 20301304
  • Pulkkinen and Uitto. (1999). PubMed ID: 10367729
  • 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

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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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