Ichthyosis with unusual hair shaft abnormalities in siblings.

An autosomal recessive disorder characterized by lamellar ichthyosis, an usual structural defect of the scalp hairs and amino aciduria occurred in two siblings in a South Indian family in Madras. In addition the female sibling was physically and mentally retarded. The disorder differs from typical Netherton's syndrome in several ways. The hair abnormality specific for this disorder appears to be splitting of the shaft. The possible mechanism of production of the split hairs is discussed.