Common variants are associated with elevated creatine in association studies [32];In patients with syndromic nephronophthisis caused by several genes (including NPHP3, IQCB1, CEP290, and MKS1), an additional heterozygous variant in RPGRIP1L is associated with retinitis pigmentosa [44]. This evidence concerns the gene IQCB1 and retinitis pigmentosa.