Cockayne syndrome (CS) is a rare disorder featuring growth deficiency, premature aging, and pigmentary retinal degeneration, as well as other findings. It is a genetic disease in which people are unable to repair DNA damage occasionally produced from rapid periods of growth or environmental exposures (e.g. exposure to UV radiation from sunlight). Without this normal DNA repair process, individuals have restricted growth and development, as well as other problems.
CS is generally classified into four subtypes based on the age of onset and the severity of the associated symptoms. In CS type I, children develop normally for the first year of life but begin having symptoms later in life. CS type II is characterized by an early onset where symptoms are observed at birth (i.e. congenital). CS type III can occur later in the child's growth and development. It is generally a milder form of the disease. A fourth form of CS, referred to as Xeroderma pigmentosa-Cockayne syndrome (XP-CS), exhibits combined features of both CS and another DNA repair disorder called Xeroderma pigmentosa.
Cockayne Syndrome affects less than one per 250,000 children. It occurs equally among males and females. There is no known racial predilection.
Children with CS may have any or all of the following:
Cockayne Syndrome is a genetic disease caused by defects in the body's ability to repair DNA. Scientists have identified several defective genes that can lead to the various forms of Cockayne syndrome. The type of CS that results depends on the location of the abnormal gene. The gene that is associated with CS type I (CSA gene) is found on chromosome 5. The impaired production and use of DNA repair components resulting from these defective genes contributes to the growth abnormalities and symptoms associated with CS.
Identifying a child with Cockayne Syndrome can often be very difficult depending on the type of CS since many of the characteristic problems associated with the disease develop gradually. A diagnosis is generally made based on the observation of any combination of the characteristic symptoms described above. The diagnosis can be confirmed through a variety of laboratory procedures and imaging studies that include MRI or CT to identify characteristic brain structural defects or tests that determine how easily UV light kills skin cells. Other tests that might be performed include an electroencephalogram (EEG) to assess for seizure activity, audiometry to assess for hearing loss, and an electroretinogram to look for abnormalities of the retina.
There is currently no cure for Cockayne Syndrome. The treatment plan for affected individuals focuses on controlling the symptoms associated with the disease. Individuals with CS must limit the amount of time that they spend exposed to direct sunlight due to their increased sun sensitivity. People with CS should apply high SPF sunscreen (45 or higher) and wear protective clothing (e.g. hats, long sleeved shirts, and pants) to reduce exposure to UV radiation. Dermatologists are often consulted to provide further advice and treatment. Hearing and vision problems are detected through routine checks and follow up. Associated symptoms such as cataracts can be surgically repaired. Nutritionists and dentists are also integral parts of the care-giving team. These professionals can offer guidance to patients and parents on the special dietary and oral hygiene needs of CS individuals. The ultimate goal of the treatment strategy for CS is to facilitate and optimize the physical and mental development and well-being of the affected individual.
The outcome for patients with Cockayne Syndrome largely depends on the severity of the genetic damage and symptoms associated with the disease as well as the individual's general state of health. In general individuals with Cockayne Syndrome have a shortened lifespan. Death usually occurs during adolescence, but survival into adulthood is possible. Fortunately, there is no increased risk for cancer that is a common feature of other DNA repair defects.
Share and Care Cockayne Syndrome Network, Inc.
http://www.cockayne-syndrome.org/
This site, in multiple languages, shares basic information about Cockayne Syndrome including how it can be treated, characteristic features, and current research news.
It also contains a chat room.
Genetics Home Reference
http://ghr.nlm.nih.gov/condition=cockaynesyndrome
Good patient friendly website with comprehensive information, links for patient support, and other websites.
Xeroderma Pigmentosa Society
A national group that is designed to help families.
Cockayne syndrome - The Knowledge Database of the Swedish National Board of Health and Welfare: www.sos.se/smkh/2002-110-6/2002-110-6.htm
Genereviews: http://www.geneclinics.org/profiles/cockayne/
E-medicine: www.emedicine.com/ped/topic424.htm
http://www.ncbi.nlm.nih.gov/disease/cockayne.html
Harrison's Online: www.harrisonsonline.com
Behrman. Nelson Textbook of Pediatrics, 17th ed. p. 2194 (Elsevier, 2004).
