Bannayan-Riley-Ruvalcaba syndrome

BRRS is caused by specific mutations in the PTEN gene. The PTEN gene provides instructions for making a protein that is found in almost all tissues in the human body. The protein acts as a tumor suppressor, which means that it plays a role in preventing cells from growing and dividing too rapidly or in an uncontrolled way.

Diagnostic criteria have not been established for BRRS; however, BRRS may be suspected based on the presence of signs and symptoms. Although genetic testing is available for the PTEN gene, it is estimated that only about 65 percent of individuals with a clinical diagnosis of BRRS have a detectable PTEN gene mutation.

BRRS is inherited in an autosomal dominant pattern, which means an individual needs to only inherit one mutated copy of the PTEN gene in order to have the condition. In some cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family.

The most serious consequences of Bannayan-Riley-Ruvalcaba syndrome (BRRS) relate to the increased risk of cancers. Individuals with BRRS and PTEN mutations are currently thought to have the same cancer risks as individuals with Cowden syndrome. The cancer risks for individuals with Cowden syndrome are as high as 10% for thyroid cancer, 5-10% for cancer of the lining of the uterus (endometrium) and up to 50% for breast cancer. Other cancers, such as those of the skin, kidneys and brain, may also be associated with Cowden syndrome. It is not clear whether these risks apply to individuals with BRRS who do not have PTEN mutations.

Because of this increased risk of developing these cancers, an important aspect of management is cancer surveillance. Screening recommendations have not been established for BRRS. However, it has been suggested that individuals with BRRS and a PTEN mutation should follow the same surveillance as individuals with Cowden Syndrome.

Although Bannayan-Riley-Ruvalcaba syndrome is rare, the true prevalence of is unknown. Because of the variable and often subtle external characteristics of this condition, many individuals remain undiagnosed.

Treatment is based on the specific signs and symptoms present in the individual. Screening recommendations for BRRS have not been established; however, recent studies have suggested that people with BRRS, especially those with a known mutation in their PTEN gene, should undergo increased surveillance of cancer affecting the breast, thyroid, endometrial, and kidney.