Aetiology

The aetiology of ulnar dysplasia is unknown but suggested theories include:

• genetic:
  • sporadic gene mutation most frequent
  • occasionally autosomal dominant familial predisposition
  • syndromic associations, inherited in an autosomal dominant manner:
    • orofacial malformations
    • Cornelia de Lange's syndrome
    • Schinzel Syndrome
    • femur-fibula-ulna syndrome
• extrinsic:
  • hormonal exposure
  • no clear link with thalidomide exposure

One pathogenetic theory is that of an injury to the zone of polarizing activity which dictates the morphogen gradient governing antero-posterior patterning