TULP1 and retinitis pigmentosa 1: To investigate whether TULP1 mutations produce misfolded proteins, we focused on missense mutations that either: 1) affect the highly conserved C-terminal tubby domain with the highest prevalence in RP or LCA patients (R420P, I450K, and F491L) or 2) were uniquely located outside the tubby domain (D94Y) [41,42].