Laboratory studies of a family manifesting premature exfoliation of deciduous teeth.

In a previous publication, we described the clinical and radiographic findings of a family in which the children manifested premature exfoliation of the deciduous teeth. We now report for the same family the results of extensive laboratory studies performed on blood and urine, analysis of periodontal microflora, and a family pedigree. We demonstrated the presence of putative periodontal pathogens in the subgingival microflora, elevated levels of serum antibodies reacting to Bacteroides gingivalis, Capnocytophaga gingivalis, and C. sputigena in 2 of the children, and significantly suppressed monocyte chemotaxis in all 3 children. Phosphoethanolamine was found in the urine of the father and all 3 children, but not in the mother. Likewise, serum alkaline phosphatase was abnormally low for all 3 children, and was at the extreme low end of normal range for the father, but was normal for the mother. On the basis of the alkaline phosphatase and phosphoethanolamine measurements, we assigned a diagnosis of hypophosphatasia to the 3 children. Phosphoethanolamine and alkaline phosphatase were also abnormal in the paternal grandmother and her brother. The son of this brother who was deceased had a daughter manifesting premature loss of the primary teeth. The data are consistent with an autosomal dominant mode of transmission. In the light of our findings, hypoplastic cementum must be considered in the etiology of some forms of early-onset periodontitis.