JEB with pyloric atresia is caused by mutations in the α6β4 integrin gene. It presents at birth with widespread blisters and erosions. Although milia are not common, scarring and nail dystrophy frequently are obsverved. Congenital localized absence of skin and ear malformations have been reported. Oral erosions may occur, and dental enamel hypoplasia and dental caries may be more common. The key feature is the presence of pyloric atresia.
Pyloric atresia is the presence of a stricture or narrowing in the stomach at the pylorus, a muscle, that prevents stomach contents from passing into the intestines. Affected infants develop abdominal distention, vomiting, dehydration and electrolyte abnormalities within the first few weeks of life, and death is possible if pyloric atresia is not recognized and treated promptly through surgery.
Diagnosis may be aided by an ultrasound or contrast-enhanced X-ray such as an upper gastrointestinal barium study. Abnormalities of the genitourinary tract also have been reported. Other systemic findings such as poor growth, anemia, and blistering and other problems involving the trachea/respiratory tract and eyes are not seen. There is no increased risk of skin cancer.