Craniofacial anthropometric pattern profile in hypohidrotic ectodermal dysplasia--application in detection of gene carriers.

Hypohidrotic ectodermal dysplasia (HED) is characterized by clinical manifestations of severe hypodontia or anodontia, hypotrichosis, hypohidrosis, and specific facial appearance. Affected males show complete expression of clinical features of this condition. Their mothers, who are gene carriers, express only some signs, which are usually very mild. Currently available clinical methods are not sufficient for routine identification of the HED heterozygous gene carriers. The purpose of this study was to identify and describe the facial characteristics of HED patients and their mothers and to evaluate the usefulness of craniofacial pattern profile analysis (CFPP) in the diagnosis of this syndrome and the detection of gene carriers. In this study six affected males and their mothers were evaluated. Z-scores for each variable were calculated and compared with age- and sex-matched controls. Anthropometric analysis showed a specific dysmorphic pattern in CST patients that includes decreased skull base width (t-t: -1.67 Z); decreased forehead width (ft-ft: -1.8 Z), decreased midface depth (sn-t: -2.02 Z), markedly decreased total facial height (n-gn: -3.4 Z), and markedly decreased maxillary arc (t-sn-t: -2.5 Z). Gene carriers showed a similar tendency in their pattern profiles. They showed the same tendency towards lower Z-values for forehead width, facial height, and mouth width. The values for these measurements were between those of the affected and healthy controls. The most pronounced findings were increased head width (eu-eu: +2.83 Z), increased lower face width (go-go: +2.06 Z), and reduction of total facial height (n-gn: -0.95 Z). They also displayed increased nose width (al-al: +2.41 Z) and increased biocular distance (ex-ex: +2.01 Z). When used in conjunction with other methods the anthropometrics pattern profile analysis can considerably enhance detection of gene carriers for HED and increase objective assessment of the craniofacial region in HED patients.