BBS4 and Bardet-Biedl syndrome: Bardet–Biedl syndrome is a multisubunit complex with involvement of eight proteins coded by BBS1, BBS2, BBS4, BBS5, BBS7, TTC8, BBS9, and BBIP genes. Most of the Bardet–Biedl syndrome cases in Europe and North America present with mutations in either BBS1 or BBS10 genes.