Is it Islamically permissible to abandon an engaged woman after paying her mahr on the pretext that her mother's maternal uncle is afflicted with vitiligo, and is the popular inherited belief that prohibits marriage to anyone whose family carries this disease a justification for that?

If a woman is of good character and religious commitment, there is no impediment to marrying her due to popular traditions that have no basis. If the parents command abandoning the marriage to her, one should try to convince them. If they insist, then one must distance oneself from her, unless there is a fear of falling into an unlawful relationship with her; in that case, do not abandon the marriage to her, for obedience to parents is obligatory except in disobedience to the Creator. However, if the marriage contract has been concluded with her and the parents command divorcing her, scholars have differed regarding the obligation of obedience, and Ibn Taymiyyah preferred that it is not obligatory.