MKKS and Bardet-Biedl syndrome: Thus, there is a general consensus that BBS patients with pathogenic variants in MKKS/BBS6, BBS10 and BBS12 genes develop a more severe phenotype than those with changes affecting BBSome components such as BBS1 (Billingsley et al., 2010; Imhoff et al., 2011; Castro-Sánchez et al., 2015).