Patients with Stargardt 3 disease (STGD3), an early-onset macular dystrophy, have C-terminal ELOVL4 mutations that lead to a premature stop in ELOVL4 protein translation, creating a truncated transmembrane protein without an endoplasmic reticulum dilysine retention signal (KXKXX). Here, ELOVL4 is linked to Stargardt disease 3.