Definition: Genetic diseases of skeletal development.

Classification

 Chondrodysplasias (ostechondrodysplasias with defects of the tubular bones or axial skeleton)

• short-trunk chondrodysplasias
  • achondrogenesis
  • hypochondrogenesis
  • spondyloepiphyseal dysplasia congenita
  • Kniest dysplasia
  • dyssegmental dysplasia
  • atelosteogenesis (spondylohumerofemoral hypoplasia)
  • boomerang dysplasia
  • fibrochondrogenesis
  • Schneckenbecken dysplasia

• non-short-trunk chondrodysplasia with platyspondyly
  • achondroplasia
  • thanatophoric dysplasia (Cases 10552 and 10556)
  • thanatophoric dysplasia with cloverleaf skull
  • metatropicdysplasia
  • opsismodysplasia
  • spondylodysplasias (PLSDs) (Torrence, San Diego, Luton)

• short-rib dysplasias (with or without polydactyly)
  • asphyxiating thoracic dysplasia (Jeune syndrome)
  • Ellis-van Creveld syndrome (chondroectodermal dysplasia)
  • short-rib dysplasias with polydactyly (Short rib-polydactyly syndromes) (Case 10557 and 10558)
  • unclassified short-rib dysplasias

• chondrodysplasia punctata group (stippled epiphysis, chondrodysplasia calcificans congenita)
  • Greenberg dysplasia
  • dappled diaphysis dysplasia
  • rhizomelic type chondrodysplasia punctata
  • Conradi-Hünermann type chondrodysplasia punctata
  • tibial-metacarpal type chondrodysplasia punctata
  • brachytelephalangic type chondrodysplasia punctata

• campomelic dysplasia
• kyphomelic dysplasia (short-limbed capmtomelic dysplasia)
• diastrophic dysplasia
• Larsen syndrome
• Desbuqois syndrome
• mesomelic dysplasias
• acromesomelic dysplasia
• otopalatodigital syndrome

 osteodysplasias with abnormal bone density

• osteogenesis imperfecta
• osteopetrosis
• pycnodysostosis
• osteosclerosis (dominant osteosclerosis type Stanescu)
• infantile cortical hyperostosis (Coffey disease)

 osteochondrodysplasias with defective mineralization

• hypophosphatasia

 osteochondrodysplasias with metabolic anomalies

• mucolipidoses (MLs)
  • mucolipidosis II (ML2) (I-cell disease)
  • mucolipidosis III (ML3)

• mucopolysaccharidoses (MPSs)
  • mucopolysaccharidosis I-H
  • mucopolysaccharidosis I (MPS1)
  • mucopolysaccharidosis II (MPS2)
  • mucopolysaccharidosis III (MPS3)
  • mucopolysaccharidosis IV (MPS4)
  • mucopolysaccharidosis VI (MPS6)
  • mucopolysaccharidosis VII (MPS7) (beta-glucuronidase deficiency)

• GM1 gangliosidosis
• sialidosis/galactosialidosis
• mannosidosis
• fucosidosis
• aspartylglucosaminuria
• sialic acid storgae disease

 unclassified osteochondrodysplasias

• atelosteogenesis type II (McALister dysplasia)
• Glasgow round femoral inferior epiphysis chondrodysplasia
• Dapppled diaphyseal dysplasia
• Greenberg dysplasia
• lethal brittle bone syndrome
• Raine syndrome
• dysplastic cortical hyperostosis

Variants

 lethal osteochondrodysplasias
 osteochondrodysplasias with predominant metaphyseal involvement
 osteochondrodysplasias with predominant epiphyseal involvement
 osteochondrodysplasias with predominant diaphyseal involvement
 osteochondrodysplasias with major spinal involvement
 osteochondrodysplasias with multiple dislocations
 osteochondrodysplasias with predominant involvement of single sites or segments

• spine
• rhizomelic
• peripheral

 osteochondrodysplasias with decreased bone density

• osteogenesis imperfecta (OIs)
• idiopathic osteoporosis
• geroderma osteodysplasticum
• Stuve-Wiedemann syndrome

 osteochondrodysplasias with increased bone density
 osteochondrodysplasias due to disorganized development of bone constituents
 osteolyses

Case records

 Case 10552: Thanatophoric dysplasia
 Case 10556: Thanatophoric dysplasia
 Case 10557: Short rib-polydactyly syndrome
 Case 10558: Short rib-polydactyly syndrome
 Case 10610: Achondrogenesis type 2