Bardet-Biedl syndrome is an inherited disease that causes vision problems, kidney abnormalities, genital anomalies, extra fingers or toes, and mild obesity, among other symptoms. About half of people with the disease have developmental delay or mental disability.
One hallmark of the disease is a vision problem caused by degeneration of the retina. It begins as night blindness in childhood and progresses to a loss of peripheral vision. People with Bardet-Biedl syndrome can also lose central vision during childhood or adolescence. The mean age at which these adolescents become legally blind is 15.5 years. By early adulthood, they are severely visually impaired.
Kidney abnormalities are present in most people with Bardet-Biedl syndrome. The problems caused by these abnormalities can range from few functional problems to life-threatening kidney failure.
Around half of people with the disease have developmental disabilities. This can range from mild learning disabilities or delayed emotional development to severe mental disability. In some cases these delays are due in part to vision loss, while in other cases they are a direct result of the disease.
Commonly, people with Bardet-Biedl syndrome have extra fingers and/or toes and mild obesity. Males with the disease often have small genitalia. Women with the disease typically have irregular menstrual cycles and may have structural deformities of the vagina. Some also have diabetes.
Bardet-Biedl syndrome is similar to Laurence-Moon syndrome, and they have been thought to be one and the same at times. The relationship between these two syndromes is still being studied.
Bardet-Biedl syndrome is rare, affecting about 1 in 100,000 in North America and 1 in 125,000 in Europe. It is more or less common in specific populations, such as Kuwaiti Bedouins (1 in 13,500), residents of Newfoundland, Canada (1 in 17,500), and the Swiss (1 in 160,000).
There is no cure for Bardet-Biedl syndrome. Extra fingers and toes can often be surgically removed in childhood. The vision and kidney problems associated with the disease can be treated in the standard fashion by medical specialists. If kidney problems reach life-threatening levels, dialysis and/or kidney transplantation may be necessary. Diet and exercise can help control obesity. In women, vaginal malformations can be surgically corrected.
Kidney disease is a major cause of early death for people with Bardet-Biedl syndrome.
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A medical database of genetic disorders funded by the National Institutes of Health and developed at the University of Washington, Seattle. Much of the language in GeneReviews is meant for physicians and other scientists.
A registered charity in the U.K. supporting people with Laurence-Moon and Bardet-Biedl syndromes, their families and caregivers.
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Newport NP10 9AD United Kingdom
Phone: 011 44 1633 718415 (from U.S.)