While in Pakistan, we worked with organisations that supported those with genetic conditions. Those with problems were overrepresented by the children from cousin-cousin relationships. A rudimentary understanding will tell you the reason for this and the reason that cousins marrying cousins is not a good idea. Not every child born of a cousin-cousin relationship has a problem; the chances of there being problems are considerably higher than is the case for other children. If you do not intend to have children, I can't think of a reason that you shouldn't marry your cousin. Adoption is an alternative option to have children.
