Bieganski et al. (1999) described a distinct form of spondyloepimetaphyseal dysplasia in 3 boys related through their mothers, in a pattern clearly consistent with X-linked recessive inheritance. The main clinical features were short stature, abnormal face, skeletal deformities, ... Bieganski et al. (1999) described a distinct form of spondyloepimetaphyseal dysplasia in 3 boys related through their mothers, in a pattern clearly consistent with X-linked recessive inheritance. The main clinical features were short stature, abnormal face, skeletal deformities, and progressive mental retardation. Radiologically, there were epimetaphyseal changes and spine involvement. Brachydactyly was present in the hands and feet. The children were normal at birth. One of the affected males was bedridden at the age of 16 years; he had dysarthric speech, uncoordinated eye movements, sporadically occurring partial left-sided seizures, and joint contractures. Another boy died at the age of 18 years and was diagnosed a posteriori based on history and family pictures. His development was normal in the first year of life; abnormal face, slow psychomotor development, short stature, and progressive skeletal deformities were noted from his second year of life onwards. In all 3 boys, extensive biochemical tests were negative. Brain CT/MRI findings were abnormal, showing small corpus callosum, markedly delayed myelination, and cortical/subcortical cerebral atrophy. The authors distinguished the disorder from Dyggve-Melchior-Clausen disease (223800, 304950) and X-linked SEMD (300106), based on differing clinical and radiologic features and inheritance pattern.