An etiologic study of maxillonasal dysplasia--Binder's syndrome.

As the etiology of maxillonasal dysplasia (Binder's syndrome) is unclear, an attempt has been made in this study to check the presence of hereditary factors. Pedigrees have been established for 50 patients with the syndrome who had actively requested orthodontic treatment and/or plastic surgery and for whom hereditary connections had been found in 36%. In some of the subjects the propositi volunteered further family data, which were included in the study. The total number thereby became 60 families. The results did not disprove the possibility of a genetic etiology although the suspicion of an autosomal recessive inheritance may not be the full explanation for the syndrome. If the syndrome is in fact of a genetic origin, one possibility is that the syndrome is indeed inherited as an autosomal recessive trait. In that case, the hypothesis of an incomplete penetrance must be added. Another possibility is that the syndrome is a threshold character with a genetically multifactorial background. Since no frequency counts among populations are available, further studies are required to collect families with maxillonasal dysplasia and to obtain population frequency data for the syndrome.