Werner syndrome

Overview
Werner Syndrome (WRN) is a very rare, autosomal recessive disorder characterized by the appearance of premature aging.

Werner's syndrome more closely resembles accelerated aging than any other segmental progeria. For this reason, Werner syndrome is often referred to as a progeroid syndrome, as it partly mimics the symptoms of Progeria.

Pathophysiology
The defect is on a gene that codes DNA helicase and it is located on the short arm of the 8th chromosome. The disorder is directly caused by shorter-than-normal length telomere maintenance. As a result DNA replication is impaired.

Symptoms
Individuals with this syndrome typically develop normally until they reach puberty. Following puberty they age rapidly, so that by age 40 they often appear several decades older. The age of onset of Werner syndrome is variable, but an early sign is the lack of a teenage growth spurt, which results in short stature. Other signs and symptoms appear when affected individuals are in their twenties or thirties and include loss and graying of hair, hoarseness of the voice, thickening of the skin, and cloudy lenses (cataracts) in both eyes. Overall, people affected by Werner syndrome have thin arms and legs and a thick torso.

Affected individuals typically have a characteristic facial appearance described as "bird-like" by the time they reach their thirties. Patients with Werner syndrome also exhibit genomic instability, hypogonadism, and various age-associated disorders; these include cancer, heart disease, atherosclerosis, diabetes mellitus, and cataracts. However, not all characteristics of old-age are present in Werner patients; for instance, senility is not seen in individuals with Werner syndrome. People affected by Werner syndrome usually do not live past their late forties or early fifties, often dying from the results of cancer or heart disease.

Genetics


Werner syndrome is an autosomal recessive disorder. The gene associated with Werner Syndrome lies on chromosome 8 in humans.

History
Werner's syndrome is named after Otto Werner, a German scientist, who, as a student, described the syndrome as part of his doctoral thesis in 1904.