???? ??? ?? ?? ? ????? ? ?? ??? ?? ???? ??? ??? ? ??? ? ??? ? ?? ? ??? ??? ??????.Trichothiodystrophy, generally known as TTD, is a rare inherited ailment that affects numerous aspects of your body. The hallmark of the issue is hair that is sparse and easily broken. [from MedlinePlus Genetics]?? ??? ????? ??? ??? ???? ???? ??? ??? ?? ?????? ????.