This structural defect is presumably similar to those caused by missense mutations at a single cysteine in LE5 (C759F) and LE8 (C934W) and the D778Y mutation, which are mostly associated with RP (Table 1 and [10]), indicating that the usherin LE4-LE8 region is important for a photoreceptor-specific function. This evidence concerns the gene USH2A and retinitis pigmentosa 1.