Metaphyseal dysplasia of Braun-Tinschert type: report of a Japanese girl.

We report on a 7-year-old Japanese girl with metaphyseal dysplasia (MD) of Braun-Tinschert type, a recently recognized, autosomal dominant sclerosing bone dysplasia. All individuals with the disorder from four families in the literature originated from a small town in Bohemia or its vicinity. The occurrence of the disorder in a Japanese girl indicates that it is not restricted to Germans. The radiographic hallmarks of the disorder include metaphyseal undermodeling (Erlenmeyer-flask deformity); osteosclerosis of the chondroosseous junctions, metaphyseal cortices, and epiphyseal margins; and exostosis-like bone excrescences at the metaphyseal-diaphyseal junctions. In the girl we described, the latter two findings were conspicuous at age 4 years, but became less prominent with increasing age. The metaphyseal trabeculae were somewhat coarse. The humeri exhibited varus deformity, and the ulnae and fibulae mild bowing. The mean bone mineral density of the lumbar spine was lower than that of age-matched controls. The patient exhibited premature loss of primary teeth, likely to be a sign of increased periodontal bone resorption. Markers of bone formation and resorption were both increased, an indication of a high rate of bone turnover.