[Morphological characteristics of lesions of the cartilaginous growth plate in several forms of osteochondrodysplasias].

The authors have carried out a search for morphological markers for diagnosing, differential diagnosis and medico-genetic consulting of 4 forms of osteochondrodysplasias. The cells and the intercellular substance of the cartilaginous graft plate from the upper flaring portion of the ileum of the patients were investigated. A common feature of most conditions were changes on the part of the granular endoplasmatic net, which points at a disturbance in the function of the synthesis apparatus and/or of the transport of the synthesized biopolymers. No morphological changes were revealed in the cartilaginous graft plate which were pathognomonic for spondyloepiphyseal dysplasia, achondroplasia and multiple exostosis chondrodysplasia. In one of the forms of pseudoachondroplasia (its severe dominant heritable variation) there were specific inclusions in the chondrocytes of the patients, which apparently were a morphological manifestation of disturbed assembly of proteoglycan aggregates which is the basis of the pathogenesis of pseudoachondroplasia. The possibility of using this morphological marker in the clinico-genetic classification of pseudoachondroplasia, in differential diagnosis of the disease in unclear cases as well as in medico-genetic consulting of the patients' families is discussed.