We demonstrate that LRMDA coupling to Commander is essential for the RAB32-dependent biogenesis of melanosomes and show that LRMDA mutations, causative for oculocutaneous albinism type 7 (OCA7), a hypopigmentation disorder accompanied by poor visual acuity (Grønskov et al., 2013), uncouple RAB32 and Commander binding thus establishing the mechanistic basis of this disease. The gene discussed is LRMDA; the disease is oculocutaneous albinism type 7.