The mystery of monozygotic twinning I: What can Amyoplasia tell us about monozygotic twinning and the possible role of twin–twin transfusion?

Amyoplasia is a very specific, nongenetic clinically recognizable form of arthrogryposis, representing about one‐third of individuals with arthrogryposis surviving the newborn period. There is a markedly increased number of individuals with Amyoplasia who are one of monozygotic (MZ) twins, with the other twin being normal. Thus, it would appear that Amyoplasia is definitely associated with and may be caused by an MZ twinning event. The twin–twin...