On the other hand, mutations in the IQCB1 gene at the NPHP5 locus have been shown to cause a form of Senior-Loken syndrome characterized by a congenital retinal dystrophy associated with a renal dysfunction of highly variable age of onset (1st to 5th decade) [27], [28], [33]. Here, IQCB1 is linked to Senior-Loken syndrome.