What is the ruling on sex reassignment if a psychiatrist decides to refer the patient to a plastic surgeon for the procedure due to a mismatch between the gender identity in the brain and the body—for example, if one is biologically male but their mind is programmed to be female, knowing that their reproductive organs are fully formed and medicine is unable to treat this condition?

It is not permissible to change the gender of an individual who has fully developed male genitalia, even if a psychiatrist claims otherwise. Such an individual should seek treatment. The Council of the Islamic Fiqh Academy has stated that attempting to transform a fully developed male or female into the other sex is a crime and an alteration of Allah's creation, citing Allah's saying: "And I will surely command them, and they will alter the creation of Allah," and the Prophet's (peace be upon him) curse upon those who alter Allah's creation.