In the preview video for episode 1.10 of Orphan Black, Cosima is seen coughing up blood. Based on the original casting notice for the part of Sarah/Beth/Karen/Alison/Cosima, we'll find out that Cosima has cystic fibrosis. From her research Cosima discovers that the clones have "degraded" DNA, which affects their lifespan. Something else that may be significant: We haven't met a clone named "Karen," so she may be one of the nine clones that we haven't seen yet. There was no detailed information about Karen in the casting notice.