IMPDH1 and retinitis pigmentosa 1: The relative contribution of each gene to the total number of mutations was estimated as 1% RHO and 4% PRPF31. However, we did not identify causative mutations in RP1 and IMPDH1 .To the best of our knowledge, this is the first study undertaken to determine the contribution of commonly reported adRP genes, RHO, PRPF31, RP1, and IMPDH1 in RP patients from India.