Bannayan-Riley-Ruvalcaba syndrome. Macrocephaly, multiple lipomas, hemangiomata.
Incidence
autosomal dominant; existence of sporadic cases.
Clinical Characteristics
Bannayan-Riley-Ruvalcaba syndrome is a rare inherited disorder characterized by excessive growth before and after birth; an abnormally large head (macrocephaly) that is often long and narrow (scaphocephaly); normal intelligence or mild mental retardation; and/or benign tumor-like growths (hamartomas) that, in most cases, occur below the surface of the skin (subcutaneously). The symptoms of this disorder vary greatly from case to case. In most cases, infants with Bannayan-Riley-Ruvalcaba syndrome exhibit increased birth weight and length. As affected infants age, the growth rate slows and adults with this disorder often attain a height that is within the normal range. Additional findings associated with Bannayan-Riley-Ruvalcaba syndrome may include eye (ocular) abnormalities such as crossed eyes (strabismus), widely spaced eyes (ocular hypertelorism), deviation of one eye away from the other (exotropia), and/or abnormal elevation of the optic disc so that it appears swollen (pseudopapilledema). In addition, affected infants may also have diminished muscle tone (hypotonia); excessive drooling; delayed speech development; and/or a significant delay in the attainment of developmental milestones such as the ability to sit, stand, walk, etc. In some cases, multiple growths (hamartomatous polyps) may develop within the intestines (intestinal polyposis) and, in rare cases, the back wall of the throat (pharynx) and/or tonsils. Additional abnormalities associated with this disorder may include abnormal skin coloration (pigmentation) such as areas of skin that may appear "marbled" (cutis marmorata) and/or the development of freckle-like spots (pigmented macules) on the penis in males or the vulva in females. In some cases, affected individuals may also have skeletal abnormalities and/or abnormalities affecting the muscles (myopathy). Bannayan-Riley-Ruvalcaba syndrome is inherited as an autosomal dominant genetic trait. Bannayan-Riley-Ruvalcaba is the name used to denote the combination of three conditions formerly recognized as separate disorders. These disorders are Bannayan-Zonana syndrome, Riley-Smith syndrome, and Ruvalcaba-Myhre-Smith syndrome. The disorder is due to mutations in the PTEN tumor suppressing gene coding for a tyrosine phosphatase on chromosome 10q.
Precipitants
No.
Provocation Tests
No.
Diagnostic Procedures
It is a clinical diagnosis. Caused by mutation in the phosphatase and tensin homolog gene (PTEN). Full sequencing of the PTEN gene is available on a clinical basis. Virtually all missense mutations in PTEN are believed to be deleterious . Approximately 60% of individuals with a clinical diagnosis of BRRS have a detectable PTEN gene mutation. For further information, contact www.genetests.org.