Bone dysplasias, including Morquio's syndrome, studied in skin fibroblast cultures

Abstract

Bone dysplasias classified as spondyloepiphyseal dysplasias, including Morquio's syndrome, have been studied in cell culture. Skin fibroblasts from six patients with dysplasias with generalized platyspondyly, four patients with multiple epiphyseal dysplasias and three patients with epiphysometaphyseal dysplasias were studied in cell culture and compared with cultures from five normal, unrelated subjects, three patients with the X-linked recessive Hunter's syndrome and three patients with the autosomal recessive Hurler's syndrome. As both cellular metachromasia and intracellular mucopolysaccharide content had been found to be reliable cell indicators of the genetic mucopolysaccharidoses, these same parameters were studied in these bone dysplasias. On the basis of cellular metachromasia, the patients with spondyloepiphyseal dysplasias and epiphysometaphyseal dysplasias could each be divided into two subgroups, metachromatic and ametachromatic; both groups showed an increased hexose content and a normal uronic acid content. The patients with multiple epiphyseal dysplasias could be divided both histochemically and chemically into two subgroups. The metachromatic group showed increased uronic acid and hexose, whereas the ametachromatic group had normal uronic acid and increased hexose content. These findings suggest that the bone dysplasias studied, including Morquio's syndrome, are true connective tissue disorders involving the fibroblast and that cell culture offers a method for investigation at the cellular level.