????? ??? ?? ?? ?? ? ?? ??? ?? ???? , ?? ??? ????? ??? ?? ?? ?? ????? ??? ?? ?? ?? ???? ?? ??? ?? ??? ??? ?? ??? ? ??? ??? ?? ????.Trichothiodystrophy, typically called TTD, is often a uncommon inherited condition that influences many areas of the body. The hallmark of this problem is hair that is sparse and easily damaged. [from MedlinePlus Geneti