Cockayne syndrome

Cockayne syndrome is a rare disorder characterized by growth failure, impaired development of the nervous system, abnormal sensitivity to sunlight (photosensitivity), and premature aging. Hearing loss and eye abnormalities are other common features, but problems with any or all of the internal organs are possible. Cockayne syndrome is inherited in an autosomal recessive pattern.

Cockayne syndrome can be divided into subtypes, which are distinguished by the severity and age of onset of symptoms. Classical, or type I, Cockayne syndrome is characterized by an onset of symptoms in early childhood (usually after the age of 1 year). Cockayne syndrome, type II (sometimes called COFS) is an early-onset form, with severe symptoms that are apparent at birth (congenital). A few cases of type III Cockayne syndrome, which has mild symptoms and onset in late childhood, have been reported. Some individuals have combined features of Cockayne syndrome and another photosensitivity disorder called xeroderma pigmentosum, which is characterized by a wide variety of skin changes, from mild freckling to skin cancer.

Mutations in the ERCC6 and ERCC8 genes cause Cockayne syndrome. The proteins made by the ERCC8 and ERCC6 genes are involved in repairing damaged DNA, particularly the DNA in active genes. If either the ERCC8 or the ERCC6 gene is altered, DNA damage is not repaired. As this damage accumulates, it can lead to malfunctioning cells or cell death, and the signs and symptoms of Cockayne syndrome.

This article incorporates public domain text from The U.S. National Library of Medicine