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This content has been automatically translated. View original in Arabic
Why wasn't consanguineous marriage prohibited?
If it increases genetic diseases
If it increases genetic diseases
Peace be upon you, dear listeners. A medical student reached out to me for help in dispelling a doubt that was troubling him deeply. I answered his question, and he was convinced and found peace in his heart, all praise is due to God. I wanted to share the question and answer with you so that the benefit may be widespread.
I will skip parts of his message for brevity. After the greeting, he writes:
"I am a medical student. A question began to form in my mind due to my studies in genetics and hereditary diseases, but unfortunately, it took root in my heart until it became a doubt that haunts my sleep and follows me everywhere. In short, this doubt is: How did Islam permit opening the door to marriages between relatives when science proves conclusively that it is a major cause of the exacerbation of hereditary diseases (Autosomal recessive disorders) and harm to future generations?"
He continues:
"I am certain that in the religion of God, there is an answer to everything, but I have fallen short in reaching it. The matter, Doctor, is no longer merely an academic discussion—it has begun to spoil the joy of worship and devotion for me greatly. I feel an increasing gap between what I study in medicine and my religious convictions. I know that permission does not imply recommendation, but why did the Sacred Law not close this door or explicitly warn against it, given that harm is probable and observable?"
Here is the response in several points, the most important of which is the last:
Statistically speaking, studies indicate a limited increase in recessive genetic diseases when marrying first cousins, rising from 1.7% to only 2.8% above the normal rate found in the general population, as cited in a reference paper in Genetics in Medicine.
This means that more than 97% of children born to marriages between relatives are free of these diseases. Is it legislatively wise to close a broad door of social benefits due to a limited statistical increase?
Ask yourself: Should Islam forbid every action that might increase the likelihood of a certain disease or harm? If we follow this logic strictly, we would have to forbid marriage for anyone over forty or childbirth after forty, because the risks of chromosomal diseases like Down syndrome increase. We would also have to forbid marriage to women with diabetes, high blood pressure, or obesity, as the relative risk of pregnancy and birth complications is higher for them.
Moreover, if the Sacred Law forbade everything that carries even a slight potential for harm, we would have to forbid medical and nursing professions due to the risk of infection, forbid driving cars and flying in airplanes due to the risk of accidents, and forbid sports due to the risk of injury. The Sacred Law bases its rulings on the predominance of harm and leaves room within permissible actions for human movement.
If we say that marrying first cousins increases the likelihood of disease by a certain percentage, while marrying more distant relatives results in a lower percentage, what is the threshold at which the Sacred Law should forbid marriage? Should it stand at 2%, 1%, or half a percent? Marriage, in general, carries the possibility of complications. Does wisdom dictate forbidding marriage entirely because of these percentages?
Today, with the availability of genetic testing, both close and distant relatives can undergo genetic counseling before marriage, which can reveal the likelihood of hereditary diseases. The Sacred Law establishes general rules that apply to all times and places and does not base rulings on technical advancements that did not exist at the time of legislation. The Sacred Law established the "original permissibility" and encouraged people to seek knowledge and take necessary measures, including the use of screening tools.
Permitting marriages between relatives takes into account social conditions and needs. Completely closing this door would create legal hardship and conflict with human reality. Many tribes live in geographical or social isolation, and necessity drives them to intermarry.
Moreover, such marriages carry human dimensions. A cousin may marry his orphaned or widowed cousin to protect her, provide for her family, and preserve her dignity—a social benefit that outweighs the limited increase in the likelihood of disease. Forbidding such marriages entirely could open the door to greater corruption and forbidden relationships among those who develop natural emotional attachments. Islam expanded the circle of what is lawful to cut off the desire for what is forbidden. Whoever desires his female cousin should come to her through lawful means.
The Sacred Law did not command marriages between relatives but permitted them. There is a vast difference between permission and recommendation. In fact, some Islamic scholars even encouraged "taghrib al-nikah" (marrying distant relatives) to avoid weakening the lineage. In Siyar A'lam al-Nubala, it is narrated that Imam al-Shafi'i said:
"Any household whose women do not marry outside their kin and whose men do not marry outside their kin will have foolish offspring."
It is also narrated that Umar ibn al-Khattab, may God be pleased with him, said to the family of al-Sa'ib:
"You have weakened your lineage; go and marry strangers so that your lineage does not weaken."
The birth of a sick child—whether in marriages between relatives or otherwise—even if it is a sorrowful matter, is not outside the decree and wisdom of God. The religious duty is to care for and support such a child, and this is part of the trials, as God the Exalted says:
"Who created death and life to test you [as to] which of you is best in deed—and He is the Exalted in Might, the Forgiving." (Quran 67:2)
We are in a house of trials.
Most importantly: whoever builds their certainty in Islam on sound and firm foundations will not be shaken by doubts, because they refer ambiguous matters to clear ones. The principle that your certainty should waver with the slightest doubt means that the "table of your faith" is not firmly established.
The failure of the educational system lies in its inability to build this firm faith or teach sound thinking, turning sciences in the minds of young people into doubts they cannot control. Therefore, I urge everyone to regularly attend beneficial knowledge courses that build certainty and to know that Islam, built on great certainties, has answers to questions—even if we do not know them at the moment.
We ask God to guide us all to what He loves and is pleased with. Peace be upon you and God’s mercy.