To quote Sir Thomas Fairbank (4), who described multiple epiphyseal dysplasia as a distinct clinical entity in 1935, this disease is “a rare congenital developmental error characterized by mottling or irregularity in density and outline of several of the developing epiphyses, and dwarfism.” Because the deformities of the ossification centers of the carpals and tarsals and of the epiphyses of the long bones may resemble those seen in the Morquio-Brailsford type of osteochondrodystrophy, the condition had been previously classified as atypical Morquio's disease or atypical osteochondrodystrophy. The good prognosis of multiple epiphyseal dysplasia as to crippling, and the fact that no treatment other than osteotomies for correction of long bone deformities is required, make especially important its recognition and differentiation from other growth disturbances presenting superficially similar radiographic findings. Of the cases reported in the literature, some, such as Fairbank's large series, show no definite hereditary or familial tendencies; other reports indicate a definite hereditary and familial distribution (3, 6, 7), particularly one series in which there were 10 cases in a single family (6). The 3 cases to be presented here occurred sporadically; it may be significant, however, that 2 of the patients had parents who were definitely of less than average height. Parents and siblings, all of whom were examined clinically and roentgenographically, showed no demonstrable stigmata of any growth disturbance. Case Reports Case I (Figs. 1–9): H. N., a white boy, was seen first at six and a half years because of difficulty in walking. The parents stated that he had flatfeet and toed in badly at birth, a condition which was treated by a Denis Browne splint. He had always been smaller than normal, walked with a waddling gait, and could not run. The child was of healthy appearance. 43 inches in height, and of normal intelligence. Both feet were extremely flat and pronated, and the gait was waddling. The lower extremities were moderately bowed, with palpable thickening at the epiphyseal regions at both ends of the tibiae and prominent fibular heads. There was internal torsion of both tibiae, so that, with the patellae pointing straight up, the feet were internally rotated. Knees and hips had free mobility. The Trendelenburg test was negative. The spine was straight; posture and body proportions were normal. Roentgenograms showed marked irregularity of all epiphyseal ossification centers and of the tarsals and carpals. Metaphyseal irregularities were present, particularly at the medial tibial condyles. As compared with the tibia, comparative overgrowth of the fibula was present bilaterally. It was decided that the difficulties in walking were due primarily to the flatfoot deformities, and arch supports were prescribed. The child was seen again eight months later because there had been no improvement in his gait and his ability to run.