Figure 3. Summary of the Retinitis Pigmentosa 1 (RP1) mutation pattern in patients with retinitis pigmentosa among different ethnic populations. Most RP1 mutations are single nucleotide substitutions producing a premature stop codon or insertion/deletion changes resulting in a truncated protein. Only a few missense variants have been found to be disease causing. So far only in Chinese missense variants have been found to be more than truncated mutations.