There are no authentic Hadiths which forbid
marriage to relatives. The incidence of retardation happens by the will and decree of Allah and is not caused by marriage to relatives as is widely believed. It is impermissible to prevent procreation for fear of having retarded children. It is recommended to have Tawakkul (putting one’s trust in Allah) and assume the best about Allah. May Allah grant us success. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.