Werner syndrome is a very rare, autosomal recessive disorder whose most recognizable characteristic is premature aging. For this reason, Werner syndrome is often referred to as a progeroid syndrome, as it partly mimics the symptoms of Progeria.

Individuals with Werner syndrome age rapidly following puberty, so that by the time they reach age 40 they often appear as though they are several decades older. Patients with Werner sydrome 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. The average age at death of Werner patients is 47, usually as a result of cancer or heart disease.

Werner syndrome is an exceedingly rare disorder, with some estimates suggesting that it afflicts approximately 1 in 1,000,000 individuals worldwide. Some populations do seem more suceptible to Werner syndrome. These include individuals of Japanese descent.

In 1996 the gene responsible for Werner syndrome was identified (and named WRN) and found to be a member of the RecQ family of helicases. Other members of this family include the genes responsible for Bloom syndrome (BLM gene), and a subset of Rothmund-Thomson (RECQ4 gene) patients.

Research into the biological role of the WRN protein is ongoing, but current evidence strongly suggests a role for WRN in the resolution of Holliday junctions . Roles in non-homologous end joining (NHEJ) and the restoration of stalled replication forks have also been suggested.

Werner syndrome is named after Otto Werner , a German student who described the syndrome as part of his doctoral thesis in the early 1900's.