Cockayne syndrome:A genetic disorder that involvesprogressivemultisystem degeneration and is classified as a segmental premature-agingsyndrome.Cockayne syndromeis characterized by dwarfism, prematurelyaging, visual problems anddeafness,sensitivityto sunlight, andmental retardation.
Cockayne syndrome is a转录- andDNArepair deficiency syndrome. The syndrome arises from mutationsinthe CSA and CSBgenes. The CSAgenehas been mapped tochromosome5. The CSBproteinis at the interface of transcription andDNA repairand is involved in transcription-coupled and globalgenomeDNA repair, as well as in general transcription.
Children with Cockayne syndrome usually have poor growth before and after birth and are mentally retarded.Eye problemsincluderetinaldegeneration,optic nerveatrophy, sunken eyes, poor lid closure and drying of the角膜. The ears tend to be malformed with hearing loss. The head is abnormally small (microcephaly). Thearms和腿是不成比例的ly long with large hands andfeetandflexioncontractures of joints. The children burn after even minimal sun exposure. They suffer steady deterioration of their neurons. Their abilities to hear, to see, even to feel orsmellare progressively lost.Deathis often from earlyatherosclerosis.
Thediseaseis inherited as anautosomal recessivetrait. The gene, called CSA, is on chromosome 5. Parents with one CSA gene are normal. Each of their children stands a 1 in 4 (25%) risk of receiving two CSA genes, one from each parent, and of having Cockayne syndrome.
There are several types of Cockayne syndrome. In Type I, the classic form of Cockayne syndrome, the boys and girls usually die in their teens. In Type II, which rarer and more severe, death usually occurs by age 6 or 7.
The syndrome is named for Edward Alfred Cockayne (1880-1956), a Londonphysicianwho concentrated on diseases of children, particularly hereditary diseases.His'Inherited Abnormalities of theSkinand its Appendages,' published in 1933, was an extensive collation offamilypedigrees from the literature. Cockayne reported the syndrome in 1946.
