Since you are writing on the internet, use that internet to research the issue of first cousin marriages and the health complications that exist in recorded numbers that have existed for many decades.  Health issues and general lower levels of sound health, medical issues that require inordinate amounts of medical attention in the Western world are quite apparent. It is not just the lack of medical facilities or the means to attend for medical advise or treatment in the third world. The issue is a serious one, not a spurious one. Look it up.