OCA2 is a melanosomal transmembrane protein essential for melanin biosynthesis and pigmentation. It functions as a chloride channel that generates a melanosome-specific anion current, working in concert with ATP-driven proton pumps to establish and maintain the acidic pH required for optimal tyrosinase activity 1. This pH regulation is critical for melanin synthesis from tyrosine and melanosome maturation 1. OCA2 is a major determinant of eye color variation, particularly brown and blue eye color, and contributes to ethnic skin color determination 2. Loss-of-function mutations in OCA2 cause oculocutaneous albinism type 2 (OCA2), an autosomal recessive disorder characterized by generalized hypopigmentation of hair, skin, and eyes 2. OCA2 is the second most common form of oculocutaneous albinism after OCA1, accounting for approximately 10-30% of cases depending on population 3. Clinical manifestations include congenital nystagmus, iris hypopigmentation, foveal hypoplasia, reduced visual acuity (20/60 to 20/400), photophobia, and optic nerve misrouting 2. Recently, OCA2 variants have been associated with asthma-plus-eczema co-morbidity, suggesting broader roles in epithelial barrier and immune function 4.