[Studies on monilethrix].

Monilethrix is a disorder of the hair manifested by fragile, beaded hair and baldness. The four children described below showed no regulary rhythm of node and internode formation. Light microscopy supported the hypothesis that periodic inhibition of keratin synthesis explains the production of the constriction. Scanning electron microscopy shows longitudinal ridging of the internodes in monilethrix and distinctive surface irregularity. Chromatography of urine for argininosuccinic acid do not support the theory that this hair abnormality is a metabolic defect.