Here are some facts about Cockayne syndrome, a rare genetic disorder caused by mutations in the genes that repair DNA.
Cockayne Syndrome Facts, Signs and Symptoms
The National Institutes of Health Genetics Home Reference defines Cockayne syndrome as a rare genetic disorder characterized by premature aging and short stature. Cockayne syndrome (also known as the Neill-Dingwall Syndrome, or the Weber-Cockayne syndrome) is so rare that it is estimated that its occurrence is less than 1 in 100,000 births.
The genetic abnormality is characterized by microcephaly (small size of the head), underdevelopment, immature nervous system, and photo sensitivity (sensitivity to sunlight). Severe tooth decay, hearing loss, eye deformities, and problems with various internal organs are also common in people who suffer from Cockayne syndrome.
Cockayne Syndrome Genetics
Cockayne syndrome is the result of a genetic defect in genes that code for enzymes that participate in repairing DNA. During a person’s lifetime the genetic material is constantly damaged by a multitude of internal and external factors. All things being equal the damage is repaired. But if the enzymes that participate in the process are mutated and do not function then DNA damage accumulates which eventually leads to cell death. It is this cell death that contributes to some of the symptoms of Cockayne syndrome such as premature aging. The causative mutated genes are ERCC6 and ERCC8 and their full names are "excision repair cross-complementing rodent repair deficiency, complementation group 6" and "excision repair cross-complementing rodent repair deficiency, complementation group 8."
Pattern of Inheritance
Cockayne syndrome has an autosomal recessive pattern of inheritance, which means that two copies of the altered gene (ERCC6 and/or ERCC8) need to be present for the disease to manifest. Carrier parents with a mutation will usually not know that they have an abnormal gene as on its own it is not enough to cause the condition. When a child receives two copies of the altered gene (one from the father and the other from the mother) then the disease appears.
Cockayne syndrome has no cure at the present time. The symptoms are managed and treatment is directed at alleviating symptoms. For example, physical therapy and assistive devices to maintain joint movement and use of sunscreens is recommended to protect against the effects of sunlight exposure.