Congenital absence of permanent teeth in a six-generation Chinese kindred

We report on rare, heritable, permanent tooth agenesis in a large Chinese k indred. The congenital absence of permanent teeth except the first and seco nd accessory teeth was observed in 52 individuals through six successive ge nerations in the kindred comprising 328 members. Clinical assessments were carried out, and inheritance mode and spousal influence of the anomaly on t heir offspring mere analyzed. Consequently, the anomaly was transmitted in an autosomal dominant fashion with incomplete penetrance (P = 0.88), and no significant clinical manifestations other than the oligodontia were found, A geographical or environmental effect on the affected individuals was obv iously eliminated, because any who are related to the kindred but live unde r the same conditions are fully healthy, The disorder we describe, therefor e, differs from any previously reported oligodontia/anodontia syndromes. Th e oligodontia ranged from a few teeth to the whole set of teeth, and usuall y occurred at a period from age 7 or 8 years, the time when primary teeth a re normally replaced by permanent teeth, to the forties. Roentgenography of the affected persons indicated that only the first and/or second accessory teeth with tooth buds developed as permanent teeth. In fact, the diphyodon tic germination sometimes occurred in the oral cavity of the affected indiv iduals. (C) 2000 Wiley-Liss, Inc.