Blomstrand osteochondrodysplasia: three novel cases and histological evidence for heterogeneity

Blomstrand osteochondrodysplasia (BOCD) is a rare, autosomal recessive, let hal skeletal dysplasia characterized by generalized osteosclerosis and adva nced skeletal maturation. The histopathological characteristics of three no vel cases (two isolated cases and a sib-pair) of BOCD are presented and cor related with the clinical and radiographical findings, and the relevant lit erature is reviewed. The results of our study confirm the existence of two separate types of BOCD, which we propose naming type I: the severe, 'classi cal' form, and type II: a less severe form.