= heritable bone dysplasia with shortening of intermediate segments (radius + ulna or tibia + fibula)

1. Langer type autosomal recessive
   • mental impairment
   • mesomelic shortening of limbs
   • hypoplasia of ulna + fibula
   • hypoplasia of mandible with short condyles
2. Nievergelt type autosomal dominant
   • severe mesomelic shortening of lower limbs
   • marked thickening of tibia + fibula in central portion
   • clubfoot (frequent)
3. Reinhardt type: autosomal dominant
4. Robinow type: autosomal dominant
5. Werner type: autosomal dominant
6. Lamy-Bienenfeld type autosomal dominant
   • ligamentous laxity
   • shortening of radius + ulna + tibia
   • absent fibula
   • normal femur + humerus

• shortening of all long bones at birth, most marked in tibia + radius
• modeling deformity with widening of diaphysis
• mild to moderate bowing
• hypoplasia of fibula with absent lateral malleolus
• short + thick ulna with hypoplastic distal end
• Madelung deformity of wrist
• hypoplasia of a vertebral body may be present