Does Islam permit marriages with ones paternal or maternal uncle/aunt's children? If yes - then under what circumstances?
Please shed some light on this issue as I find it confusing to believe, especially when it is scientifically proven that marrying your cousins is not a healthy practice.
Your advice would be duly appreciated.
Cousins do not belong to the categories that are prohibited to marry in Islam. Only blood and half blood brothers - sisters, fathers - mothers, uncles – aunts, and grandfathers – grandmothers, beside brothers and sisters in fosterage (breast fed by the same woman) are prohibited to marry. The fear of having genetic problems in their children is definitely a problem in these cases. Also, the natural human instinct of feeling differs towards ones first kin [like brother and sister] from that which is towards more distant kin [like cousins].
On the other hand, cousins are not close enough relatives to be vulnerable to the same high risk factor of genetic problems. However, although cousins are allowed to get married, due to the lower risk of having genetic problems in their children, the presence of even this low risk of having such problems made such marriage not the best recommended. Omar Ibn Al Khattab said: ‘Marry the strangers to become healthier.’
The same risk, of having health problems with the children if one marries a cousin, actually happens, if one marries a woman over 35 years old. The risk is also the same if a man or a woman chooses a spouse with a family history of a certain disease. Still, the possibility is not strong enough to incriminate this marriage.
Nevertheless, one should try to make use of all possible precautions. Among these precautions, are the modern scientific techniques of genetic tests. These are now available, for marrying couples, to detect the possibility of facing such troubles. Marrying couples can undergo these tests before they getting married. These tests are recommended, not only for cousins, but also for everybody, because even strangers might be exposed to such problems. Thus, the possibility of having a genetic problem in marrying a cousin is not, exceptionally, strong enough, to make it prohibited.
Another important factor, worth mentioning, is the nature of the oriental societies. They were mostly, some are till now, tribal. People only get to know one another through family circles. This permission corresponds with the general policy of the Islamic law that tends towards widening, rather than narrowing people's choices in life, unless a thing is a ‘real’ threat.