Sunday, December 2, 2012

Diagnosis (2/3)


DNA Mutation Analysis

Based on the results of the skin biopsy, genetic testing may be performed to confirm the specific gene and DNA mutation(s) present.
Molecular genetic studies (DNA analysis) are done after the sub-type of Epidermolysis Bullosa (EB) has been confirmed by skin biopsy. Molecular studies are done to identify the specific genetic mutation and to determine the mode of inheritance (recessive vs. dominant). This information is helpful for family planning and makes prenatal diagnosis of subsequent pregnancies possible.
After immunoflurescent microscopy DNA mutational analysis is the final step in elucidating the underlying molecular defect, and in most cases, it reduces the number of genes to be screened. DNA is extracted from blood of the patient and family members. Initial mutation screening is performed by restriction fragment-length polymorphism analysis, hotspot analysis, and finally, direct DNA sequencing.
But in a small number of people, DNA mutation analysis is unable to identify the specific mutations that are suspected to be present based on the results of the skin biopsy.

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