Bannayan-Riley-Ruvalcaba syndrome

Other Names: BRRS; Riley-Smith syndrome; Macrocephaly multiple lipomas and hemangiomata; Ruvalcaba -Myhre-Smith syndrome; RMSS; Bannayan-Zonana syndrome; BZS; Macrocephaly pseudopapilledema and multiple hemangiomas

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is a genetic condition that leads to the growth of both non-cancerous and cancerous tumors. Bannayan-Riley-Ruvalcaba syndrome is a genetic condition characterized by a large head size (macrocephaly), multiple noncancerous tumors and tumor-like growths called hamartomas, and dark freckles on the penis in males. The signs and symptoms of Bannayan-Riley-Ruvalcaba syndrome are present from birth or become apparent in early childhood.

The features of Bannayan-Riley-Ruvalcaba syndrome overlap with those of another disorder called Cowden syndrome. People with Cowden syndrome develop hamartomas and other noncancerous growths; they also have an increased risk of developing certain types of cancer. Both conditions can be caused by mutations in the PTEN gene. Some people with Bannayan-Riley-Ruvalcaba syndrome have had relatives diagnosed with Cowden syndrome, and other individuals have had the characteristic features of both conditions. Based on these similarities, researchers have proposed that Bannayan-Riley-Ruvalcaba syndrome and Cowden syndrome represent a spectrum of overlapping features known as PTEN hamartoma tumor syndrome instead of two distinct conditions.

Epidemiology

The prevalence of Bannayan-Riley-Ruvalcaba syndrome is unknown, although it appears to be rare. Several dozen cases have been reported in the medical literature. Researchers suspect that the disorder is underdiagnosed because its signs and symptoms vary and some of them are subtle.

Cause

About 60 percent of all cases of Bannayan-Riley-Ruvalcaba syndrome result from mutations in the PTEN gene. Another 10 percent of cases are caused by a large deletion of genetic material that includes part or all of this gene. The protein produced from the PTEN gene is a tumor suppressor, which means that it normally prevents cells from growing and dividing (proliferating) too rapidly or in an uncontrolled way. If this protein is missing or defective, cell proliferation is not regulated effectively.

Uncontrolled cell division can lead to the formation of hamartomas and other cancerous and noncancerous tumors. The protein produced from the PTEN gene likely has other important functions within cells; however, it is unclear how mutations in this gene can cause the other features of Bannayan-Riley-Ruvalcaba syndrome, such as macrocephaly, developmental delay, and muscle and skeletal abnormalities.

When Bannayan-Riley-Ruvalcaba syndrome is not caused by mutations or deletions of the PTEN gene, the cause of the condition is unknown.

Inheritance

Autosomal dominant pattern, a 50/50 chance.

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

Symptoms

The following list includes the most common signs and symptoms in people with Bannayan-Riley-Ruvalcaba syndrome (BRRS). These features may be different from person to person. Some people may have more symptoms than others and symptoms can range from mild to severe. This list does not include every symptom or feature that has been described in BRRS.

Symptoms may include:

• Large head size (macrocephaly)
• Increased birth weight,
• Intellectual disability
• Autism spectrum disorder
• Benign skin tumors
• Hair follicle tumors (trichilemmomas)
• Raised bumps on tongue and gums (oral papillomas)
• Fatty tumors (lipomas)
• Growths in the colon (colon polyps)
• Dark colored freckles on the penis (macular pigmentation)
• Increased risk for cancer, especially thyroid, breast, uterine, and kidney

People with BRRS may be born with a large head and increased birth weight. Childhood symptoms may include developmental delay, intellectual disability, and/or autism spectrum disorder. As they get older, people with BRRS often develop non-cancerous (benign) growths under the skin and in internal organs. These growths may include fatty tumors, hair follicle tumors and bumps on the tongue and gums. As adults, people with BRRS are at increased risk to develop breast, thyroid, colon, uterine, and kidney cancers.

Diagnosis

Bannayan-Riley-Ruvalcaba syndrome (BRRS) is diagnosed based on a clinical exam, symptoms, and genetic testing. Diagnostic criteria have been published for the PTEN hamartoma syndromes. BRRS is one of the syndromes. The test is used to look for a PTEN genetic mutation. It is not a routine test. It is usually given to people based on family history, symptoms, or previous diagnosis of cancer, especially cancer of the breast, thyroid, or uterus. A PTEN test is usually a blood test. During a blood test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Treatment

There is no specific treatment for Bannayan-Riley-Ruvalcaba syndrome (BRRS). Treatment is based on management of the specific signs and symptoms. Screening recommendations for people with BRRS include increased surveillance of cancer affecting the breast, thyroid, uterus, and kidney.

Specialists who may be involved in the care of people with BRRS include:

• Medical geneticist
• Neurologist (nerve specialist)
• Dermatologist (skin specialist)
• Gastroenterologist (digestion specialist)
• Urologist (kidney and bladder specialist)

NIH genetic and rare disease info

• NIH info on Bannayan-Riley-Ruvalcaba syndrome

Bannayan-Riley-Ruvalcaba syndrome is a rare disease.

Bannayan-Riley-Ruvalcaba syndrome Resources
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