Familial congenital pseudarthrosis of the ulna.

A mother and daughter, both presented with congenital pseudarthrosis of the ulna due to neurofibromatosis. The daughter is one of identical twins, the second twin not having a pseudarthrosis. The mother's uncle also had pseudarthrosis of the tibia. This suggests a complex variable genetic inheritance pattern for pseudarthrosis in neurofibromatosis. Despite having had no treatment, the mother had minimal symptoms, minimal deformity, and no radial head dislocation.