TSPAN12 and Norrie disease: So far, mutations in 6 candidate genes have been attributed to the development of FEVR including Norrie disease pseudoglioma (NDP; OMIM 300658) [1, 9, 10, 14, 15], Frizzled-4 (FZD4; OMIM 604579) [1, 2, 7, 8, 14–20], Low density lipoprotein receptor like protein 5 (LRP5; OMIM 603576) [1, 2, 6, 14–16, 19, 21], Tetraspanin-12 (TSPAN12; OMIM 613138) [1, 2, 4, 5, 22–25], Zinc finger prortein-408 (ZNF408) [1, 3] and Kinesin family member 11 (KIF11) [26, 27].