It is well established that mutations in the RPGRIP1 gene are associated with cilium dysfunctional syndromes, such as Joubert syndrome (MIM #213300) 45, Leber's hereditary optic neuropathy (LHON, MIM #535000) 46 and Meckel syndrome (MIM #249000) 1, 47. This evidence concerns the gene RPGRIP1 and Leber hereditary optic neuropathy.