This gene encodes a protein which contains tetratricopeptide repeats (TPR), similar to O-linked N-acetyglucosamine transferase. Mutations in this gene have been observed in patients with Bardet-Biedl syndrome type 4. BBS proteins do not show extensive homology with proteins of known function. Based on the observations that BBS8 localizes to the basal body of ciliated cells and expression of the Caenorhabditis elegans orthologues of several BBS proteins are limited to ciliated cells, it has been hypothesized that BBS is the result of a defect in cilia assembly or function. The functions of the proteins encoded by the Bardet