PATIENT WITH DOUBLE HETEROZYGOSITY FOR ACHONDROPLASIA AND PSEUDOACHONDROPLASIA, WITH COMMENTS ON THESE CONDITIONS AND THE RELATIONSHIP BETWEEN PSEUDOACHONDROPLASIA AND MULTIPLE EPIPHYSEAL DYSPLASIA, FAIRBANK TYPE

We present a 7 1/2-year-old girl with achondroplasia and pseudoachondr oplasia. Her mother has achondroplasia and her father has pseudoachond roplasia. Radiographic manifestations of these two conditions from inf ancy to age 6 years are outlined. The findings in this patient are com pared with those of achondroplastic patients and pseudoachondroplastic patients of similar ages. Our review of radiographs of many pseudoach ondroplastic patients and subsequently of those of patients with multi ple epiphyseal dysplasia (MED), Fairbank type, reinforced our opinion that pseudoachondroplasia and multiple epiphyseal dysplasia, Fairbank type, are closely related conditions. MED, Fairbank type, may be the m ildest form of pseudoachondroplasia. Recently published electron micro scopic findings also suggest this. (C) 1993 Wiley-Liss, Inc.