Analysis of hair from alopecia congenita.

Two patients with alopecia congenita had short vellus hairs of the scalp but some apparently normal-sized hairs in other areas. Both fibrous and matrix proteins were detected in the scalp hairs by polyacrylamide gel electrophoresis (PAGE), and x-ray diffraction analysis revealed a normal alpha pattern. Amino acid analysis showed a decreased cystine content suggesting a quantitative or qualitative change in the matrix component. Scanning electron microscopic examination revealed pits and bulges in the cuticle cells which may be related to wearing a wig. The data suggest a defect in the development of the follicle rather than an abnormality in a component of the hair.