The histological and ultrastructural features of the epiphyseal plate in Morquio type A syndrome (mucopolysaccharidosis type IVA).

Tissue from the epiphyseal plate of a patient with Morquio type A syndrome (mucopolysaccharidosis type IVA) was studied by undecalcified histological and electron microscopical techniques. Cartilage cells in the plate were vacuolated to a variable degree. The orderly proliferating structure of the epiphyseal plate was absent and calcification was markedly reduced. The related bone tissue was morphologically normal although reduced in quantity.