Bardet-Biedl syndrome (BBS) is a genetic disorder that is a part of a larger group of conditions called ciliopathies. Cilia are microscopic projections from cells that have important functions in cell movement and cell communication. Ciliopathies are diseases that affect cilia, and the genes that are associated with BBS have important roles in the function of cilia. Disruptions in these genes result in cilia not working as they should, which can cause the symptoms associated with BBS.
BBS is estimated to be diagnosed in about 1 in 250,000 people.
Bardet-Biedl syndrome occurs due to genetic changes (sometimes called mutations or pathogenic variants) in both copies of one of the BBS-related genes.
Everyone inherits two copies of the BBS genes, one from each parent. When both parents have one copy of a non-working gene, they are carriers of BBS. Carriers do not have the disease, but when two carriers have a child, there is a 1 in 4 chance (25%) with each pregnancy that the child will have BBS. This pattern of inheritance is called autosomal recessive. When a person has pathogenic variants in both copies of a gene related to BBS, they develop the condition.
BBS is typically diagnosed in childhood. The features of BBS can be different in different people w
