Oral phenotype and variation in focal dermal hypoplasia

Focal dermal hypoplasia (FDH) or Goltz Syndrome (OMIM# 305600) is an X-linked dominant ectodermal dysplasia caused by mutations in the PORCN gene. This gene encodes an endoplasmic reticulum transmembrane protein that is involved in processing the embryonically critical WNT signaling proteins. Individuals diagnosed with FDH were recruited to participate in the study through the National Foundation for Ectodermal Dysplasia. Individuals were evaluated to characterize the FDH phenotype. Each participant completed a brief dental survey and oral evaluation using artificial light. To identify the oral soft and hard tissue findings 19 individuals (16 female and 3 male) participated with a median age of 10 years (range 2-56 years). Soft and hard tissue defects were present in 68% (13) and 94% (18) of the patients, respectively. Dental anomalies were highly prevalent with 68% (13) demonstrating vertical enamel grooving, 52% (10) having peg shaped tooth deformities, and 78% (15) having enamel hypoplasia with or without discoloration. Cleft lip and cleft palate presented in 15% (3) of the participants. Other findings included 57% (11) having intra-oral lipoma or papilloma with no site predilection. Dental malocclusions were common with 63% (12) having some degree of malocclusion with 15% (3) of participants having class III malocclusion with an anterior dental cross bite. Participants frequently reported speech problems or difficulty with chewing (73%; N = 14). This study shows there is marked variation in the oral phenotype of individuals with FDH and underscores the important role of WNT signaling in oro-facial development.