Ultrastructural abnormalities of the chondrocytes of the growth cartilage of a type of poly-epiphyseal dysplasia with a probable autosomal recessive transmission.

In two cases of polyepiphyseal dysplasia with a probable autosomal recessive transmission, ultrastructural abnormalities were found in the chondrocytes of the tibial epiphyseal growth plate. The largest part of the chondrocytes is occupied by many large vacuoles. They are bounded by a single membrane and have an electron-lucent background in which electron-opaque granules and delicate spiral filaments are visible. The ultrastructural abnormalities suggest a storage disorder probably limited to the chondrocytes.