CYP4V2 and Bietti crystalline dystrophy: All patients with CYP4V2 mutations in this study showed characteristic fundus manifestations of BCD, including numerous yellow-white dots crystalline deposits distributed on the posterior pole and mid-periphery, pigment deposits, retinal vascular attenuation, diffuse RPE atrophy and choriocapillaris atrophy, except in two patients (P6.1 and P9) in whom atypical forms of BCD fundus changes were noted.