Epidermolysis Bullosa: A Rare Genetic Disorder
Epidermolysis bullosa (EB) is a group of rare genetic conditions that result in easy blistering of the skin and mucous membranes. Blisters occur with minor trauma or friction and are painful. Its severity can range from mild to fatal. Those with mild cases may not develop symptoms until they start to crawl or walk. Complications may include esophageal narrowing, squamous cell skin cancer, and the need for amputations.
EB is due to a mutation in at least one of 18 different genes. Some types are autosomal dominant while others are autosomal recessive. The underlying mechanism is a defect in attachment between or within the layers of the skin. There are four main types: epidermolysis bullosa simplex, dystrophic epidermolysis bullosa, junctional epidermolysis bullosa, and Kindler syndrome.The diagnosis is suspected based on symptoms and confirmed by skin biopsy or genetic testing.
There is no cure for the condition.Management involves wound care, pain control, controlling infections, nutritional support, and prevention and treatment of complications.About half a million people are affected globally.It occurs equally commonly in males and females.Children who are affected may be bullied by other children or experience inappropriate comments from adults.
Epidermolysis bullosa simplex
Epidermolysis bullosa simplex is a form of epidermolysis bullosa that causes blisters at the site of rubbing. It typically affects the hands and feet, and is typically inherited in an autosomal dominant manner, affecting the keratin genes KRT5 and KRT14. Therefore, there is a failure in keratinisation, which affects the integrity and the ability of the skin to resist mechanical stresses.
Junctional epidermolysis bullosa
Junctional epidermolysis bullosa is an inherited disease affecting laminin and collagen. This disease is characterised by blister formation within the lamina lucida of the basement membrane zone and is inherited in an autosomal recessive manner. It also presents with blisters at the site of friction, especially on the hands and feet, and has variants that can occur in children and adults. Less than one person per million people is estimated to have this form of epidemolysis bullosa.
Dystrophic epidermolysis bullosa
Dystrophic epidermolysis bullosa is an inherited variant affecting the skin and other organs. Dystrophic epidermolysis bullosa is caused by genetic defects (or mutations) within the human COL7A1 gene encoding the protein type VII collagen (collagen VII). DEB-causing mutations can be either autosomal dominant or autosomal recessive. Epidermis bullosa pruriginosa and Albopapuloid epidermolysis bullosa (Pasini's disease) are rare subtypes of this disease.
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