Genetic classification of ichthyosis.

Ichthyosis has been classified on a genetic basis. Four varieties--ichthyosiform erythroderma, lamellar ichthyosis, Refsum's syndrome and the Sjögren-Larsson syndrome--are inherited as autosomal recessive traits. One type is inherited as a sex-linked recessive trait while another variety of ichthyosis (with or without atopy), bullous ichthyosiform erythroderma, and very rarely ichthyosis hystrix are due to autosomal dominant genes.