Parents

What is Bardet- Biedl syndrome (BBS)?
Bardet- Biedl syndrome (BBS) is a rare genetic disease which affects many organs. Visual defects, extra fingers and toes, obesity, learning disabilities, reproductive system malformations/infertility and kidney abnormalities are considered the cardinal features. Secondary features include fused/short digits, diabetes mellitus, behavioural abnormalities, poor coordination, absence of smell, abnormalities of mouth/teeth, stomach/intestine, endocrine glands, thorax and abdomen. The clinical diagnosis requires the presence of either four major features or three major features and two minor features. The disease can be caused by changes (mutations) in 26 different genes, one of them is BBS1.

How many people are affected by Bardet-Biedl syndrome?
The number of patients with BBS in the world is not known and it is different among different geographic areas. In North America and Europe, approximately 1: 120.000 and 1: 160.000 individuals are affected. Males and females are equally affected.

What causes Bardet-Biedl syndrome?
BBS is caused by genetic mutations in BBS1 or in other causative genes. Typically, parents are asymptomatic, but carry one copy of genetic mutation. A couple of carriers have 25% risk to have a child with the disorder.

How to diagnose Bardet-Biedl syndrome?
The diagnosis is based on clinical criteria, according to Beals (1999). When available, genetic studies may confirm the diagnosis.     

How to manage Bardet-Biedl syndrome?
To date, there is no specific therapy and patients need a supportive treatment. Because of the involvement of many organs, the contribution of different specialists and a personalized follow-up are required.