Should people with diseases have children?

Of course they should. If everyone who had a disease did not have children, it would mean a huge amount of people never having children, which would affect the population. A person who has a disease can still have perfectly healthy children, as not all diseases are genetic. People who have diseases can make major contributions to society, as can their children. Even if the disease does get passed on to children, this can help scientists who are looking for ways to treat and even cure the disease. For these and many, many other reasons, like discrimination, of course people with diseases should have children.