<unk>  is an extremely rare disorder in most populations and the frequency of the disease has not been measured in most populations. However, the disorder is relatively more common amongst people of Central and Eastern European Ashkenazi Jewish background. Approximately 1 in 48,000 Ashkenazi Jews are affected by<unk> , who account for about one-third of affected individuals worldwide.<unk> 's Syndrome Registry The<unk> 's Syndrome Registry lists 265 individuals reported as suffering from this rare disorder (as of 2009), collected from the time it was first recognized in 1954. The registry was developed as a surveillance mechanism to observe the effects of cancer in the patients, which has shown 122 individuals have been diagnosed with cancer. It also acts as a report to show current findings and data on all aspects of the disorder.
Bloom syndrome
Plummer–Vinson syndrome
Schnitzler syndrome
Secretan's syndrome
Galloway Mowat syndrome
Mucus fishing syndrome
Naegeli–Franceschetti–Jadassohn syndrome
König's syndrome