To date, mutations in 10 cilia-related genes (NPHP1, INVS/NPHP2, NPHP3, NPHP4, IQCB1/NPHP5, CEP290/NPHP6, SDCCAG8/NPHP10, WDR19/NPHP13, TRAF3IP1 and CEP164) have been identified in SLS patients (Figure 1) [1,4]. This evidence concerns the gene NPHP4 and Sjogren-Larsson syndrome.