Prenatal diagnosis of pyloric atresia-junctional epidermolysis bullosa syndrome in a fetus not known to be at risk

Abstract

Junctional epidermolysis bullosa with pyloric atresia (PA-JEB) is a highly lethal, inherited, autosomal recessive disease. Thus far, prenatal diagnosis of this syndrome was only realized on pregnancies at risk for recurrence. We report the case of a 26-year-old woman, first cousin to her husband, who had undergone amniocentesis for polyhydramnios. The karyotype was normal but the amniotic fluid contained acetylcholinesterase. A targeted scan at 25 weeks' gestation did not find spina bifida, but polyhydramnios with a dilated stomach, and several other anomalies: echogenic particles in the amniotic fluid, a thin skin which closely adhered to the nasal bones, narrow nostrils, abnormal ears, fisted hands, malposition of both first toes, and kidney malformation. Despite no previous case in the family, it was thought that sonographic findings were suggestive of the PA-JEB syndrome. A fetal skin biopsy was carried out at 28 weeks' gestation. The ultrastructural examination of fetal skin displayed JEB. Genetic analysis detected a homozygous mutation in the gene encoding integrin alpha 6. Termination of pregnancy was carried out at 29 weeks' gestation. These results illustrate that in the case of a fetus not known to be at risk, diagnosis of PA-JEB can be achieved by ultrasound findings leading to fetal skin biopsy and ultrastructural examination of blistered epidermis. Some new sonographic signs should raise the possibility of significant cutaneous desquamation and blister formation in a fetus, especially when there is positive amniotic acetylcholinesterase coupled with elevated alpha-fetoprotein or suspected pyloric atresia.