???? ??? ?? ?? ? ????? ? ?? ??? ?? ???? ??? ??? ? ??? ? ??? ? ?? ? ??? ??? ??????.Trichothiodystrophy, generally termed TTD, can be a rare inherited affliction that affects quite a few elements of the human body. The hallmark of this condition is hair that is definitely sparse and easily broken. [from MedlinePlus Genetics]?? ???? ???? ??? ?? ???? ?