Married to a close relative:

Is it unacceptable in the eyes of Quantum to marry cousins?

If someone likes you, would it be unreasonable to marry him?

In fact, it is very dear to say that it is cursed to be with someone who is not related to marriage or has no blood relationship.
Imam Ghazzali mentions in the hadith of the Prophet (peace and blessings of Allaah be upon him) that you should not marry a woman who is close to you, because it can make your child weak and talented.

A 2013 UK research report published in the Lancet, one of the world's most influential medical journals, found that marrying uncles, cousins ​​and cousins ​​doubled their children's chances of developing birth defects.
While irrelevant, another point is that before marriage, the blood of the bride and groom should be tested so that they do not make hereditary rules like thalassemia.