Fundus examination revealed retinal degeneration in all the patients (Ben-Rebeh et al. 2016). Using WES, a novel RRM2B c.786G>T variant was identified, as a plausible disease-causing, in  two affected sibling of Afrikaner ancestry, in South Africa, presenting a recessive sensorineural hearing impairment, associated with rod-cone dystrophy and  kidney disease; the variant was replicated in two unrelated South African patients with similar clinical phenotype suggesting a founder effect  (Roberts et al. 2020). This evidence concerns the gene RRM2B and Cone rod dystrophy.