Causes of Epidermolysis Bullosa
The causes of epidermolysis bullosa are genetic mutations that affect the proteins responsible for holding skin layers together. Epidermolysis bullosa does not result from infection, allergy, or poor hygiene. Parents pass it down through families, either from one or both, depending on the type.
Genetic Mutations
Mutations in genes that provide instructions for making the proteins that bind the layers of skin cause EB. The most commonly affected genes include:
KRT5 and KRT14 in EB simplex
COL17A1 and LAMA3, LAMB3, LAMC2 in junctional EB
COL7A1 in dystrophic EB
These mutations interfere with the skin’s ability to maintain integrity when exposed to stress or friction. Without strong connections between layers, even minor trauma can cause blistering and peeling.
Inheritance Patterns | Causes of Epidermolysis Bullosa
The condition is usually inherited in one of two ways:
Autosomal dominant – one copy of the mutated gene (from one parent) is enough to cause the condition
Autosomal recessive – both parents must pass on a faulty gene; each parent is usually a carrier without symptoms
Dystrophic and junctional types are often inherited recessively and tend to be more severe. EB simplex is typically inherited in a dominant pattern and may cause milder symptoms.
Spontaneous mutations can also occur, meaning a child may be affected even with no family history. Furthermore, these cases still result in lifelong EB, though the risk of passing it on to future children may vary.
Risk Factors
There are no environmental or lifestyle risk factors for EB. However, consanguinity (marriage between close relatives) increases the risk of passing on recessive conditions like EB, especially in rural or traditional communities.
In South Africa, genetic testing is not widely available in the public health system, making diagnosis more difficult. As a result, doctors often rely on clinical signs and skin biopsy to identify the type of EB.
Understanding the causes of epidermolysis bullosa helps families make informed decisions, consider genetic counselling, and plan for long-term care. Accurate diagnosis also helps direct treatment and support.
[Next: Symptoms of Epidermolysis Bullosa →]
