Trichothiodystrophic hair reveals an abnormal pattern of viscoelastic parameters.

Separate analysis and quantitative determination of the viscous and elastic parameters of hair performed in 5 patients with trichothiodystrophy and in 20 sex- and age-matched control subjects revealed an abnormal pattern of the mechanical behavior of trichothiodystrophic hair. The change of the viscous parameter is probably associated with the profound alterations in the high-sulfur proteins of the interfilamentary matrix; the changes in the elastic parameters may be related to the reduced stability of the irregularly arranged microfibrils of trichothiodystrophic hair caused by the marked reduction of the disulfide cross-links.