Junctional epidermolysis bullosa (JEB) an inherited condition that causes the skin to be extremely fragile leading to severe blistering. Small skin injuries and even simply rubbing or scratching can lead to blister formation and skin loss. Based on severity junctional epidermolysis bullosa is classified into two main types, generalized severe form (previously known as Herlitz JEB) and the generalized intermediate form (previously known as non-Herlitz JEB). This test identified genetic variants in the LAMB3 gene linked to the generalized severe form.
LAMB3 provides instructions to produce one part (subunit) of the laminin 332 protein. Laminin 332 is important for attaching the top layer of our skin (called the epidermis) to the layers underneath, which strengthens and stabilizes our skin. People affected with JEB make defective or non-functional laminin 332 protein, and without it the cell in the top layer become more fragile. Just a scratch or minor friction can cause the skin layers to separate resulting in blister formation.
Take this test to find out whether you are a genetic carrier of the LAMB3 variants and are at risk of passing it to your children. This is intended to be a carrier screening test for couples who are considering to start a family.
Genetic variants of several genes are associated with JEB. This test only identifies genetic variation in the LAMB3 gene linked to JEB generalized severe. JEB is inherited in an autosomal recessive pattern, which means two defective copies of the gene must be inherited in order for the disease to manifest.
LAMB3 variants account for about 70% of JEB cases and the three variants included in this test account for approximately 48% of LAMB3-related junctional epidermolysis bullosa cases.
This test looks at a genetic variants of the LAMB gene linked to junctional epidermolysis bullosa generalized severe form.
- rs80356682 A (R635X)
- rs80356680 A (R42X)
- rs80356681 A (Q243X)
Understanding your carrier status will help you understand the risk of passing on JEB to your children. While a carrier do not typically show signs and symptoms of the condition there is a 25% chance the child will inherit the disease if both parents are carriers.
Characteristic symptoms include
- fragile skin
- Severe blistering
- Recurrent infections due to scarring from extensive blistering
- Difficulty swallowing leading to undernourishment
- Difficulty breathing due to build up of scar tissue in the respiratory tract
- Other complications can include fusion of the fingers and toes, joint deformities, alopecia