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last update : 25-05-2010
Symbol EXT1
Location 8q24.11
Name exostoses, multiple, 1
Other name(s)
  • multiple cartilaginous exostoses
  • diaphyseal aclasis
  • multiple osteochondromatosis
  • Corresponding gene EXT1
    Other symbol(s) EXT, MCE
    Main clinical features
  • characterized by multiple projections of bone capped by cartilage, most numerous in the metaphyses of long bones, but also occurring on the diaphyses of long bones
  • flat bones, vertebrae, and the ribs may also be affected, but the skull is usually not involved
  • Genetic determination autosomal dominant
    Related entries . see also trichorhinophalangeal syndrome 2 (TRPS2) or Langer-Giedion syndrome
    Function/system disorder osteo-articular
    Type other
  • defects in EXT1 and the resulting reduction in heparan sulfate lead to enhanced Indian Hedgehog diffusion causing an increase in chondrocyte proliferation and delayed hypertrophic differentiation