Gringas and Chen (2001) describe a number of mechanisms which can lead to differences between monozygotic twins, the most relevant here being chorionicity and amniocity.
Gringas a Chen (2001) beschreiwe Variante vu Mechanismen, déi Schwankungen tëscht monozygotesche Zwillinge verursaachen, déi am wichtegsten sinn Chorionizitéit an Animositéit.