A Mongolian patient with hypohidrotic ectodermal dysplasia with a novel P121S variant in EDARADD.

INTRODUCTION: Hypohidrotic ectodermal dysplasia is a genetic disorder characterized by diminished or a lack of sweating, congenital missing teeth, and sparse or absent hair. Three genes, EDA, EDAR, and EDARADD, all related to tumor necrosis factor signaling, have been reported as responsible genes for this disorder. Among them, the largest numbers of mutations have been identified in EDA, and only two mutations identified in EDARADD. MATERIALS AND METHODS: DNA analysis of EDA, EDAR, and EDARADD was performed on a Mongolian patient by polymerase chain reaction-direct sequencing. RESULTS: The 5-year-old Mongolian individual had no erupted deciduous or permanent teeth. A panoramic radiograph showed only one tooth in the right mandible. His hair and eyebrows were sparse, but he did not have a short stature. He showed diminished sweating. The nails of his fingers and toes were normal. Based on these conditions, he was diagnosed with hypohidrotic ectodermal dysplasia. There was no gene mutation of EDA or EDAR. A novel heterozygous variant (P121S; c.361C>T) was identified in the death domain of EDARADD (NM_080738). No other member of his family was affected, and this variant was not identified in his parents or maternal grandparents. CONCLUSION: This study reports an individual affected with hypohidrotic ectodermal dysplasia with a novel heterozygous P121S variant in the death domain of EDARADD.

Early childhood caries and related risk factors in Mongolian children.

OBJECTIVES: The aims of this study were to investigate the dental caries experience among 1-5 year-old children in the two areas of Ulaanbaatar city, and to examine the relationship of dental caries experience with socioeconomic status, eating behaviors, oral hygiene habits, dental plaque accumulation and Mutans Streptococci level. METHODS: In 2004/2005, 670 children from the two areas were examined and a questionnaire survey was conducted. Mutans streptococci (MS) levels in the children's and mothers' dental plaque were evaluated using Dentocult SM. RESULTS: Dental caries prevalence (72%) and mean dmft (4.4) were very high in both areas, however, children in the central area showed higher caries severity than those in the suburban area in 3-5-year-olds (p < 0.05). Higher family income and education level of the mothers were significantly associated with children's higher caries experience. Furthermore, dental caries showed a significant positive relationship with sweets intake and a negative relationship with tooth brushing habits of the children. The children's caries experience was significantly and positively associated with modified debris index (m-DI) scores, and the MS levels in their own and their mothers' dental plaque. Area, sweets intake, prolonged breastfeeding, and high MS level in the dental plaque resulted in significant odds ratios for the development of caries. CONCLUSIONS: The prevalence of dental caries amongst 1-5 year-old children in Ulaanbaatar City, Mongolia was found to be high and was associated with socioeconomic, demographic and behavioural factors.