1/2. The orthopaedic manifestations of the langer-giedion syndrome.Less than 50 cases of langer-giedion syndrome (also known as trichorhinophalangeal syndrome with exostoses) have been reported in the English literature since its first description in 1974. Affected individuals have been described as having a bulbous nose, micrognathia, short stature, multiple cartilaginous exostoses, and large, protruding ears. We recently treated a 5-year-old, mentally retarded boy with langer-giedion syndrome for symptomatic multiple exostoses involving his proximal tibia and distal femur. This paper will highlight the musculoskeletal abnormalities found in this child and compare them to those of 43 patients reported in the world literature. The comparison reveals a very distinctive pattern of exostosis, demonstrating a primary altered growth pattern in the lower extremities and deformity secondary to marked ligamentous laxity. Orthopaedic surgeons are frequently the first consultants to see these children for their obvious osteochondromata. They must consider the diagnosis of langer-giedion syndrome to facilitate the treatment of its other manifestations.- - - - - - - - - - ranking = 1keywords = exostosis (Clic here for more details about this article) |
2/2. Cloning of the putative tumour suppressor gene for hereditary multiple exostoses (EXT1).Hereditary multiple exostoses is an autosomal dominant disorder that is characterized by short stature and multiple, benign bone tumours. In a majority of families, the genetic defect (EXT1) is linked to the langer-giedion syndrome chromosomal region in 8q24.1. From this region we have cloned and characterized a cDNA which spans chromosomal breakpoints previously identified in two multiple exostoses patients. Furthermore, the gene harbours frameshift mutations in affected members of two EXT1 families. The cDNA has a coding region of 2,238 bp with no apparent homology to other known gene sequences and thus its function remains elusive. However, recent studies in sporadic and exostosis-derived chondrosarcomas suggest that the 8q24.1-encoded EXT1 gene may have tumour suppressor function.- - - - - - - - - - ranking = 1keywords = exostosis (Clic here for more details about this article) |