DIAGNOSING EB

Laboratory diagnosis is essential to determine the (sub)type of EB and the precise cause for it at the genetic and protein levels. There are two main methods used in EB laboratory diagnosis: genetic testing and skin sample analysis.

 
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GENETIC TESTING

To perform genetic testing, blood samples are taken from the person with EB and their parents. The samples are used for the extraction of genomic DNA, which contains all the information on our individual genetic make-up. Each gene carries a unique sequence code that has a specific function as a protein. A disease-causing variant in EB-associated genes can be detected by Sanger sequencing (SS) of a specific gene or by next generation sequencing (NGS), which can analyse ALL the EB genes at once.

SKIN SAMPLE ANALYSIS

This analysis looks at changes in protein expression, localisation, and ultrastructural modifications (changes in skin components that can only be seen by electron microscopy). Immunofluorescence Mapping (IFM) examines the proteins in the skin. EB-associated proteins can be recognised by specific (antibodies) reagents. When compared to a normal skin sample, this technique can show an absent or reduced protein amount. Transmission Electron Microscopy (TEM) is used to directly examine the structural components of the skin, which cannot be seen with a conventional microscope. TEM allows samples to be magnified by as much as 10 million times. It is rarely used in standard EB diagnosis but it can be useful in solving difficult cases.

 

For more detailed information on how EB is diagnosed, download the clinical practice guidelines for laboratory diagnosis (for EB healthcare professionals) or the patient version (for people living with EB, their families, and carers).

 

Learn about the clinical signs and which genes are affected in the four main EB types and their subtypes

Find out about what causes EB and the three different ways it can be inherited

Check our FAQ page for answers to questions you have and submit a question if you can’t find the answer

 

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