Segregation analysis showed that the unaffected mother is also homozygous for the BBS12 missense variant c.1139C>T;p.T380I; therefore, we conclude that the BBS phenotype is primarily caused by BBS5 variant c.143-4_143-2ins400-500;p.?, and the BBS12 variant might—if at all—only modulate the phenotype. Here, BBS12 is linked to Bardet-Biedl syndrome.