Absent radius is a very rare medical condition in which the radius bone is not developed. This results in a typical position of the arm in which the wrist is plantarflexed and radially deviated.

The aetiology of radial club hand or radial dysplasia can be divided into:

1. sporadic cases, which are not inherited and are presumed to be due to de novo genetic mutations
2. syndromal cases; certain syndromes have a higher than expected association with radial dysplasia. Typically, organ systems are affected that develop at the same time as the upper limb:

• VACTERL or VATER syndrome
• Holt-Oram syndrome
• Edwards syndrome
• haematopoietic syndromes:
  • Fanconi anemia
  • Thrombocytopaenia with Absent Radius (TAR syndrome)
• craniofacial syndromes:
  • Nager’s syndrome
  • Goldenhar’s syndrome
  • Mobius syndrome
  • cleft lip and palate
  • Treacher-Collins syndrome
• skeletal syndromes and isolated skeletal associations:
  • Klippel-Feil syndrome
  • Sprengel deformity
  • syndactyly
  • scoliosis
• teratogens:
  • radiations
  • valproic acid
  • thalidomide

• http://holt-oram.ning.com/ social network site for those affected by the condition