Prenatal ultrasound findings of ectodermal dysplasia: a case report.

BACKGROUND: Ectodermal Dysplasia is a diverse group of inherited disorders characterized by a congenital defect in two or more ectodermal structures. Due to a fairly low incidence, to the best of our knowledge there are few clues that can assist in making an effective prenatal ultrasound diagnosis. Currently, the prenatal diagnosis of ectodermal dysplasia depends on a fetal genetic test combined with the family history. In this case report, we present a fetal case of ectodermal dysplasia with a remarkable prenatal ultrasound image, genetic testing, family history, and relevant exams of the stillbirth. CASE PRESENTATION: A multipara with a 22-week singleton male pregnancy undergoing a fetal ultrasound examination. The image showed a hypoplastic maxilla and mandible. Subsequently, the ectodermal dysplasia was defined using a family history and genetic testing. The skin pathology from the aborted fetus demonstrated a hypohidrotic type. The computed tomography (CT) reconstruction after induced labor confirmed the prenatal ultrasound findings of the maxilla and mandible. CONCLUSIONS: This case suggested that prenatal ultrasound may provide a valuable clue of ectodermal dysplasia. The diagnosis can be established using further prenatal genetic testing and a family history.

A recurrent regulatory change underlying altered expression and Wnt response of the stickleback armor plates gene EDA.

Armor plate changes in sticklebacks are a classic example of repeated adaptive evolution. Previous studies identified ectodysplasin (EDA) gene as the major locus controlling recurrent plate loss in freshwater fish, though the causative DNA alterations were not known. Here we show that freshwater EDA alleles have cis-acting regulatory changes that reduce expression in developing plates and spines. An identical T → G base pair change is found in EDA enhancers of divergent low-plated fish. Recreation of the T → G change in a marine enhancer strongly reduces expression in posterior armor plates. Bead implantation and cell culture experiments show that Wnt signaling strongly activates the marine EDA enhancer, and the freshwater T → G change reduces Wnt responsiveness. Thus parallel evolution of low-plated sticklebacks has occurred through a shared DNA regulatory change, which reduces the sensitivity of an EDA enhancer to Wnt signaling, and alters expression in developing armor plates while preserving expression in other tissues.