Herlitz Junctional Epidermolysis Bullosa: LAMA3 Related

Gene : LAMA3

What is Herlitz Junctional Epidermolysis Bullosa?

Herlitz Junctional Epidermolysis Bullosa (H-JEB) is an inherited disorder that causes defects in how the layers of skin are held together. As a result, severe blistering and erosion can occur to the skin even in response to minor injury or friction, such as rubbing or scratching. Individuals affected by H-JEB have blistering over large regions of the body beginning at birth. The blistering can also occur in the moist lining of the mouth and digestive tract, which can make it difficult to eat and digest food. Because the skin chafes and wears away easily, the person is prone to infection. Infants with this condition usually do not survive beyond the first year of life. For those who do survive, infections, hair loss, weak and brittle bones, malnutrition, slow growth, skin cancer, and other complications often occur. There is no cure for H-JEB, however medical surveillance and care may help to improve some symptoms and overall condition of life for those who survive infancy. H-JEB is cause by pathogenic variants in any one of the three genes: alpha-3 (LAMA3), beta-3 (LAMB3), and gamma-2 (LAMC2).

How is Herlitz Junctional Epidermolysis Bullosa inherited?

Herlitz Junctional Epidermolysis Bullosa is inherited in an autosomal recessive manner. This type of inheritance requires the presence of two copies of a pathogenic variant in the gene for a person to have the genetic disease. Both parents must be carriers of a pathogenic variant in the gene in order to be at risk to have an affected child. The child must inherit a pathogenic variant from each carrier parent in order to be affected. There is a 1 in 4 chance that a baby will inherit two mutated copies of the gene and be affected when both parents are carriers.

What does it mean to be a carrier?

There are generally no signs or symptoms associated with being a carrier for Herlitz Junctional Epidermolysis Bullosa. However, the risk to have a child affected with these disorders is increased. Testing of reproductive partners is recommended for carriers of Herlitz Junctional Epidermolysis Bullosa.

How common is Herlitz Junctional Epidermolysis Bullosa?

LAMA3 related H-JEB occurs in approximately 1 in 17.5 million individuals.  LAMA3 related NH-JEB occurs in approximately 1 in 2.9 million individuals.

Family References and Resources
Clinician References
What is Analyzed?
  • Full gene sequencing
Affected Systems

Bone

GI Tract

Skin

Carrier Rates
Ethnicity
Detection Rate
Carrier Frequency
General Population 98% 1 in 788

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