Osteosclerotic metaphyseal dysplasia is a rare condition characterized by developmental delay, hypotonia, and distinctive radiographic changes, including osteosclerosis localized predominantly to the metaphyses of the long bones. The shafts of the long bones are osteopenic. The skull appears ... Osteosclerotic metaphyseal dysplasia is a rare condition characterized by developmental delay, hypotonia, and distinctive radiographic changes, including osteosclerosis localized predominantly to the metaphyses of the long bones. The shafts of the long bones are osteopenic. The skull appears to be spared. Seizures and later-onset spastic paraplegia have been reported. Laboratory abnormalities include elevated alkaline phosphatase levels in some, but not all, patients. Elevated urinary pyridinoline and deoxypyridinoline levels, markers of osteoclastic activity, have also been reported (summary by Nishimura and Kozlowski, 1993 and Kasapkara et al., 2013).
Nishimura and Kozlowski (1993) reported a Japanese sister and brother, aged 11 months and 15 years, respectively, with mental retardation, hypotonia, and unique radiographic changes consisting of peripheral osteosclerosis primarily affecting the metaphyses of the long bones. Other ... Nishimura and Kozlowski (1993) reported a Japanese sister and brother, aged 11 months and 15 years, respectively, with mental retardation, hypotonia, and unique radiographic changes consisting of peripheral osteosclerosis primarily affecting the metaphyses of the long bones. Other bones (ends of ribs and clavicles, iliac crests, acetabulae, ischiopubic synchondroses, and vertebrae) were affected to a lesser degree. The shafts of the tubular bones were osteopenic. The round bones, short tubular bones, and skull were spared. Elevated serum alkaline phosphatase levels were observed in both patients. Height was less than the 3rd centile in the brother, but within normal limits in the sister. The brother developed epilepsy in childhood, which was well controlled with anticonvulsant. At age 15 years, he was noted to have spastic paraplegia. Mennel and John (2003) reported a 23-month-old male who presented with developmental delay, hypotonia, and complex seizures. Radiographic evaluation showed thick irregular transverse sclerotic bands in the metaphyses of the long bones in the upper and lower extremities with cortical thinning of the shafts of these bones. Sclerosis of the anterior ribs, iliac crests, talus, and calcaneus was also observed. The skull and spine were unaffected. The infant was initially suspected of having lead intoxication because of the radiographic changes, but the thick and irregular appearance of the metaphyseal sclerotic bands, marginal areas of epiphyseal sclerosis, and proximal tibial exostoses distinguished this condition from lead intoxication. In contrast to the patients reported by Nishimura and Kozlowski (1993), serum alkaline phosphatase was within normal limits in their patient; however, aspartate aminotransferase (AST) and creatine phosphokinase (CPK) levels were slightly elevated, and urinary pyridinoline and deoxypyridinoline, measures of bone resorption, were substantially elevated. MRI at 8 months was normal. The family history was unremarkable, and the parents were not related. Kasapkara et al. (2013) reported a 12-month-old male with hypotonia, developmental delay, and osteosclerosis of the metaphyses of the long bones of the upper and lower extremities with osteopenic shafts. Metaphyseal osteosclerosis was also detected in the short tubular bones of the hands and feet. Sclerotic bands were also seen in the anterior and posterior ends of the ribs and in the scapula and iliac, pubic, and ischial bones. The skull was unaffected. Height was within normal limits. AST and CPK levels and urinary pyridinoline and deoxypyridinoline were all elevated. MRI of the brain showed benign external hydrocephalus. The family history was unremarkable, and the parents were not related.