Epidermolysis Bullosa (EB)
Description
Epidermolysis Bullosa (EB) is a group of rare genetic skin disorders characterized by fragile skin that blisters easily. Even minor friction or trauma can cause painful blisters and sores, leading to significant challenges for those living with this condition. While there‘s currently no cure for EB, advancements in medical care are improving the quality of life for individuals affected. This blog explores the nuances of EB, from its symptoms and causes to diagnosis, management, and the inspiring stories of individuals thriving despite the challenges.
Genes Involved
Genes Involved:
EB is caused by mutations in various genes involved in the production of proteins that hold the layers of skin together. These genes can differ depending on the specific type of EB. Some of the genes implicated in EB include:
- COL7A1: This gene is responsible for producing collagen type VII, a protein essential for anchoring the skin‘s outer layer (epidermis) to the underlying layer (dermis). Mutations in COL7A1 are responsible for the most severe form of EB, known as Dystrophic EB.
- LAMA3: This gene encodes laminin-332, a protein found in the basement membrane, the layer that connects the epidermis to the dermis. Mutations in LAMA3 can cause junctional EB (JEB).
- LAMB3: This gene encodes laminin-332, similar to LAMA3. Mutations can also lead to JEB.
- LAMC2: This gene encodes laminin-332, also contributing to JEB.
- ITGA6: This gene encodes integrin alpha 6, a protein that interacts with laminin-332. Mutations can lead to Herlitz junctional EB (H-JEB), a particularly severe form.
Recognizing the Signs and Symptoms
Recognizing the Signs and Symptoms:
- Blistering: The most prominent symptom of EB is the development of blisters, often in response to minor trauma or friction. Blisters can appear anywhere on the body, including the skin, mouth, eyes, and even internal organs.
- Skin fragility: The skin of individuals with EB is extremely fragile, prone to tearing or blistering with even the slightest pressure.
- Scarring: Repeated blistering can lead to scarring, which may affect mobility and functionality. In severe cases, scarring can be extensive and disfiguring.
- Nail dystrophy: Nails may become brittle, deformed, or even detach from the nail bed.
- Hair abnormalities: Some types of EB can cause hair loss or abnormal hair growth.
- Oral lesions: Blisters and sores in the mouth can make eating and swallowing painful.
- Eye problems: EB can affect the eyes, leading to conjunctivitis, corneal ulcers, or even blindness.
Causes
Causes:
EB is caused by genetic mutations that disrupt the production or function of proteins vital for holding the layers of skin together. These mutations can be inherited from a parent or arise spontaneously in a child.
- Inherited EB: Most cases of EB are inherited in an autosomal recessive pattern, meaning both parents must carry the gene mutation for their child to inherit the condition. In autosomal dominant inheritance, only one parent needs to carry the mutated gene for their child to be affected.
- Spontaneous mutations: In some cases, EB can occur in individuals without a family history of the disease due to a spontaneous mutation that arises during the development of the fetus.
Inheritance/recurrence risk
Inheritance or Recurrence Risk:
- Autosomal recessive inheritance: If both parents are carriers of the mutated gene, there is a 25% chance that their child will inherit the condition, a 50% chance that the child will be a carrier, and a 25% chance that the child will not inherit the gene.
- Autosomal dominant inheritance: If one parent carries the mutated gene, there is a 50% chance that their child will inherit the condition.
- Spontaneous mutations: The risk of spontaneous mutations is low, but it can still occur in families with no prior history of EB.
