Some of the possible modifier alleles in the BBS-causing genes found in our cohort could be good candidates for functional studies to analyse a possible modifying effect on the BBS phenotype, e.g., IFT172, TRIM32, or WDPCP. Furthermore, we identified third alleles in other genes previously reported as possible candidates or modifiers of BBS, e.g., ALMS1, CORO2B, NPHP4, or PDE6B36,45–47. The gene discussed is WDPCP; the disease is Bardet-Biedl syndrome.