Dominant dystrophic epidermolysis bullosa

Dominant dystrophic epidermolysis bullosa (DDEB) has an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that one copy of the gene with the mutation in each cell is sufficient to cause the disorder. About 70 percent of individuals with DDEB have inherited a COL7A1 mutation from an affected parent. The remaining 30 percent have the condition as a result of a new (de novo) mutation in the COL7A1 gene. These cases occur in people with no history of the disorder in their family. Regardless of whether an individual with an autosomal dominant condition has inherited the mutation or has a new mutation, each child of the affected individual has a 50% (1 in 2) chance of also having the condition, and a 50% chance of not having the condition.^[1]

If a fetus is at risk for having DEB, a Cesarean section may be recommended to avoid vaginal delivery, which can cause trauma to the skin. It is also recommended that newborns who are at risk for having DEB are evaluated for evidence of blistering so that trauma to the skin can be avoided as much as possible.^[2]

Because of the risks to a newborn with DEB, some individuals may be interested in finding out whether the fetus has the condition before birth. The optimal time for learning about genetic risk and discussing the availability of prenatal testing is before pregnancy. Prenatal testing for pregnancies at increased risk for DEB is possible by analyzing DNA from fetal cells obtained by amniocentesis or chorionic villus sampling (CVS). However, the genetic mutation in the affected family member must be known before prenatal testing can be performed. Preimplantation genetic diagnosis (PGD) may be available for families in which the disease-causing mutation has been identified.^[2] Questions about genetic risks, genetic testing and prenatal testing can be answered by a genetics professional.

To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself. Online directories are provided by the American College of Medical Genetics and the National Society of Genetic Counselors. If you need additional help, contact a GARD Information Specialist. You can also learn more about genetic consultations from Genetics Home Reference.

There is currently no cure for all types of dystrophic epidermolysis bullosa (DEB). Treatment generally focuses on managing signs and symptoms. For some individuals, such as those that have a mild form of dominant dystrophic epidermolysis bullosa (DDEB), dystrophic nails may be the only manifestation. However, other individuals may have much more severe problems that need to be managed. Management typically focuses on treating blisters and avoiding or treating infections.^[3]

Wound care usually included treatment of new blisters by lancing and draining. Additionally in most cases, wounds are then dressed with a non-adherent material, covered with padding for stability and protection, and secured with an elastic wrap for integrity. Due to the increased risk of bacterial resistance, topical antibiotic ointments and antimicrobial dressings should be reserved for those wounds that are colonized with bacteria and fail to heal, referred to as “critical colonization."^[3][4]

Individuals with epidermolysis bullosa (EB) have increased caloric and protein needs due to the increased energy utilized in wound healing. Involvement of the digestive system in some forms of EB may limit nutritional intake. Infants and children with more severe forms of EB and failure to thrive usually require attention to fluid and electrolyte balance and may require nutritional support, including a gastrotomy feeding tube. Anemia is typically treated with iron supplements and transfusions as needed. Other nutritional supplements may include calcium, vitamin D, selenium, carnitine, and zinc.^[3][4]

Surveillance is important for individuals with DEB. Biopsies of abnormal-appearing wounds that do not heal may be recommended in some types of DEB due to predisposition to squamous cell carcinoma, beginning in the second decade of life. Screening for deficiencies of iron, zinc, vitamin D, selenium, and carnitine is typically recommended after the first year of life. Routine echocardiograms are recommended to identify dilated cardiomyopathy, and bone mineral density studies are recommended to identify osteoporosis. Activities and bandages that may traumatize the skin (including all adhesives) should typically be avoided.^[3]

Recent treatment advancements and therapies under investigation include but are not limited to^[3][4][5]: 

• Use of biological dressings to treat chronic or recurrent skin ulcers
• Bone marrow transplantation
• Intra-dermal (in the skin) injection of fibroblasts
• Protein replacement therapy (intra-dermal injection of type VII collagen) 
• Gene therapy
• Revertant mosaicism
• Gene correction technologies (ex. CRISPR)

DEBRA International has developed clinical practice guidelines for different aspects of treating EB including wound care and pain management. Click on the link to see their completed guidelines.