Methods: DNA samples were collected from members of an XLHED family and 17 unrelated HED patients (14 males and 3 females). The EDA/EDAR/EDARADD genes were PCR-amplified and sequenced. The statistical analysis of tooth agenesis in HED patients with defined EDA mutations was made.
Results: An EDA mutation Asp316Gly was identified in XLHED family, EDA mutations(FS at 36, Term. after 17 res; FS at 84, Term. after 6 res; FS at 205, Term. after 74 res; Arg153Cys; Arg156His; Tyr301Cys; Thr348Ala; Ala349Thr; Gly215Term; Gln358Term)were identified in 10 HED male patients. Among these patients, anodontia present in 13.6%, and oligodontia in all such persons. The mean number of missing teeth was 21.1. Frequency of tooth agenesis seems to be higher for mandibular teeth than for maxillary teeth. The teeth with the highest probability of absence in the maxillae were lateral incisors and the first premolars, and in the mandible was central incisors. The comparative analysis between the data of HED patients and of non-syndromic oligodontia patients with EDA mutations showed the statistically significant differences were observed at all teeth positions except the maxillary central incisors. The conical teeth were observed with a very high prevalence in HED male patients (maxillary and mandibular lateral incisors 100%, mandibular canines 100%), but it was rarely to be seen in the EDA-associated-non-syndromic oligodontia patients.
Conclusions: The tooth agenesis and tooth malformation were more severe in HED patients with EDA mutations than in the non-syndromic oligodontia patients with EDA mutations.
Acknowledgments: This work was supported by the Natural Science Foundation of Beijing.