X-linked hypohidrotic ectodermal dysplasia. Genetic and dental findings in 67 Danish patients from 19 families.

This study aimed to investigate genotype and phenotype in males affected with X-linked hypohidrotic ectodermal dysplasia (HED) and in female carriers, to analyse a possible genotype-phenotype correlation, and to analyse a possible relation between severity of the symptoms and the X-chromosome inactivation pattern in female carriers. The study group comprised 67 patients from 19 families (24 affected males and 43 female carriers). All participants had clinical signs of ectodermal dysplasia and a disease-causing EDA mutation. The EDA gene was screened for mutations by single-stranded conformational polymorphism and direct sequencing. Multiplex ligation-dependent probe amplification (MLPA) analysis was used to detect deletions/duplications in female probands. Sixteen different EDA mutations were detected in the 19 families, nine not described previously. The MLPA analysis detected a deletion of exon 1 in one female proband. No genotype-phenotype correlations were observed, and female carriers did not exhibit a skewed X-chromosome inactivation pattern. However, in two female carriers with pronounced clinical symptoms, in whom the parental origin of each allele was known, we observed that mainly the normal allele was inactivated.

Case series: Treatment considerations in x-linked hypohidrotic ectodermal dysplasia.

AIMS: To describe our treatment considerations obtained from the dental care of several boys affected with X-linked hypohidrotic ectodermal dysplasia (HED) and to discuss the different problems that may arise in connection with these kinds of treatments. STUDY DESIGN: The subject group included 10 males affected with X-linked HED, treated at the department of Paediatric Dentistry and Clinical Genetics, Copenhagen School of Dentistry. All patients were treated, after a period of adaptation, with removable prostheses and whenever necessary, composite restoration of the conical crown morphology of the maxillary incisors. Furthermore, some of the patients received an orthodontic treatment for closure/reduction of the medial diastema. RESULTS: The mean number of appointments at the department was 32 with a range from 7 to 59 appointments. In 7 out of 10 patients, the treatment was a success according to the patient, parents and dentist. In 3 out of 10 patients the treatment was not a success from the dentist's point of view: primarily due to lack of cooperation between the patient, parents and dentist. In half of the patients the deviated maxillary incisors morphology was restored and 5 out of 10 patients received orthodontic treatment for closure of the medial diastema in the maxilla. CONCLUSION: It is of utmost importance to take the motivation of the patient and parents as well as the patient's acceptance for dental treatment into consideration. Furthermore, the treatment is rather time-consuming and should involve different areas of specialisation. Finally it is vital to remember that the parents may also have undergone a prolonged dental treatment, which might reduce their patience regarding their children's treatments.

Anthropometric and cephalometric measurements in X-linked hypohidrotic ectodermal dysplasia.

OBJECTIVE: To describe the somatic development and craniofacial morphology in males affected with hypohidrotic ectodermal dysplasia (HED) and female carriers and to find clinical markers for early clinical diagnosis of possible female carriers. DESIGN: A clinical and radiographic examination of the affected males and the female carriers. SETTING AND SAMPLE POPULATION: Twenty-four affected males and 43 female carriers with a known mutation in the ED1 gene were examined in a dental clinic in either Copenhagen or Aarhus, Denmark. EXPERIMENTAL VARIABLES: Height, body mass index (BMI) and head circumference. Cephalometric analysis of the craniofacial morphology. OUTCOME MEASURE: Data on the somatic and craniofacial development in the affected males and female carriers. RESULTS: No difference was observed regarding body height in the affected males and female carriers, BMI values were lower than the mean in most affected boys and adolescence and head circumference was somewhat decreased in both groups compared to normative data. The cephalometric analysis showed a reduced maxilla length and prognathism, a normal size and shape of the mandible and a reduced sagittal jaw relationship in both HED groups. Furthermore, affected males had a retroclined nasal bone and a more anteriorly inclined maxilla. A short nose, protruding lips, reduced facial convexity and facial height, characterized the soft tissue profile of the affected males. In female carriers, the lips were significantly retruded when compared with controls. CONCLUSION: No specific somatic or cephalometric markers could be observed, in the female carrier group.