The spondyloepimetaphyseal dysplasias (SEMD) are a heterogeneous group of disorders characterized by involvement of the epiphyses, metaphyses, and vertebral bodies. Several forms include mental retardation as a feature. Classification of the SEMDs is based on clinical, radiologic, and ... The spondyloepimetaphyseal dysplasias (SEMD) are a heterogeneous group of disorders characterized by involvement of the epiphyses, metaphyses, and vertebral bodies. Several forms include mental retardation as a feature. Classification of the SEMDs is based on clinical, radiologic, and molecular findings. Genevieve et al. (2005) described an apparently novel autosomal recessive form of SEMD and mental retardation in 2 Pakistani sisters born to first-cousin parents. SEMD, severe mental retardation, microcephaly, ataxia, facial dysmorphism, and hirsutism of back and legs were noted in both girls. Facial features included coarse facies, low anterior and posterior hairline, brachycephaly, simple and flat ears, synophrys, broad nose, and full lips with eversion of the lower lip. Skeletal findings included flat vertebral bodies with irregular vertebral plates, irregular and flared metaphyses with vertical striations, small and irregular epiphyses, small carpal bones, and narrow iliac wings without lacy pelvis iliac crest. Clinical and radiologic features worsened as the disease progressed. Other investigations, including karyotype, plasma and urinary amino acids and organic acids, and blood and fibroblast lysosomal enzymes, were normal. Electron microscopy of the skin revealed an abnormally large number of small vacuoles along the cytoplasmic membrane and large vacuoles containing either myelinic or granular osmiophilic bodies. The authors suggested that the sisters may have had a metabolic disorder.
In 2 Pakistani sisters with a form of SEMD and mental retardation, Genevieve et al. (2005) excluded mutation in the DYM gene (607461), which is responsible for Dyggve-Melchior-Clausen syndrome (223800), and in the PAPSS2 gene (603005), which is ... In 2 Pakistani sisters with a form of SEMD and mental retardation, Genevieve et al. (2005) excluded mutation in the DYM gene (607461), which is responsible for Dyggve-Melchior-Clausen syndrome (223800), and in the PAPSS2 gene (603005), which is responsible for the Pakistani type of SEMD (612847).