301-519-2100 • FAX 301-519-2892 • 207 PERRY PARKWAY GAITHERSBURG, MD 20877  
 
  
SEARCH

Epidermolysis Bullosa, Junctional Type
Junctional Epidermolysis Bullosa
Herlitz Junctional Epidermolysis Bullosa
Non-Herlitz Junctional Epidermolysis Bullosa
Generalized Atrophic Benign Epidermolysis Bullosa; GABEB
Mitis Junctional Epidermolysis Bullosa

  • Laminin 5 genes (LAMB3, LAMA3, LAMC2)
  • COLXVII gene (COL17A1)
The junctional forms of epidermolysis bullosa (JEB) are a clinically and genetically heterogeneous group of severe congenital autosomal recessive blistering disorders. The Herlitz form usually results in demise during the first year of life, while the non-Herlitz, mitis and GABEB forms are less severe and affected individuals usually survive to adulthood. Blisters generally heal without scarring. The tissue separation (blister) occurs within the lamina lucida of the basement membrane and anchoring filaments may be reduced or absent. It is most useful to have appropriate immunohistochemical studies accomplished prior to beginning molecular genetic studies. GeneDx requests that the referring physician contact Beutner Laboratories in Buffalo, NY (716-838-0549) to arrange for immunohistochemical analysis of a skin biopsy from the affected individual. If these studies are consistent with absence of laminin 5 in the tissue, molecular analysis of the genes coding for the laminin 5 protein complex is appropriate. Testing at GeneDx is offered in steps: First, a targeted analysis assesses the presence of six common mutations (hotspots) in LAMB3, LAMA3, and LAMC2, which is expected to identify mutations in 40% of cases. Next, full sequencing of the LAMB3, LAMC2 and LAMA3 genes, preferably in that order, is available. Aside from the common hotspots, mutations in LAMB3 account for 30% of JEB mutations while LAMC2 and LAMA3 account for another 9% each. COL17A1 testing will disclose the remaining 12% of JEB mutations, although in most cases the phenotype is a milder non-lethal form of JEB. Please note, JEB testing in most cases is done in the neonatal period. Due to limitations of buccal swabs, a venous blood specimen (1-2 ml in EDTA) is required for infants less than 6 months of age. Cultured cells or skin are also accepted.

Information Sheet (Laminin 5 testing), including prices and CPT codes Back to the List
Information Sheet (COL17A1 testing), including prices and CPT codes  
Consent Document  
Genetic Test Sample Submission Form (Test Requisition Form) including Payment Options  
epidermolysis bullosa, junctional EB, Herlitz, Pearson, blister, bullous, bullae, Laminin, laminin5, lamininV, GABEB, LAMB, LAMB3, LAMA3, LAMC2, letalis, desmosome, scarring

© 2000 - 2008 GeneDx, Inc. All rights reserved.