Hello Swerty, I see we got new company on this thread , you are most welcome it was a getting a little bit boring, that is a very good question you posted , anyways Marriages between first cousins are allowed in Islam you can check surat an-Nisa'(4:22-24) and surat al-Ahzab (33:50) not to mention that prophet Mohammed (PBUH) married his daughter Fatima to his cousin Ali, if you read these Quranic verses you'll notice that first cousins are not listed as women to whom a Muslim cannot be married.whats your thought on muslim inbreeding<quoted text>
However it is highly preferable for Muslims to have a blood test before marriage, In Jordan for instance you cannot proceed in a marriage without a blood test.
marrying first cousins is allowed in many countries even in the west and we still don't have a solid evidence that such marriages may cause genetic diseases unfortunately some Muslims prefer to marry first cousins out of a tribal thing like to make sure the wealth stays within the tribe and this kind of reasons although Mohammed (PBUH) once said
" Narrated Abu Huraira: The Prophet said, "A woman is married for four things, i.e., her wealth, her family status, her beauty and her religion. So you should marry the religious woman (otherwise) you will be a losers " .