Finally, the DHDDS mutations known to result in autosomal recessive retinitis pigmentosa [9,10] and developmental epileptic encephalopathies [12], and NgBR mutations associated with Parkinson’s disease [34] and a congenital glycosylation disorder [33] were mapped on the heterodimer model (Figure 7). The gene discussed is NUS1; the disease is autosomal recessive retinitis pigmentosa.