TYR (tyrosinase) is a copper-containing oxidase that catalyzes the rate-limiting steps in melanin biosynthesis 1. The enzyme hydroxylates tyrosine to DOPA (3,4-dihydroxyphenylalanine) and subsequently oxidizes DOPA to DOPA-quinone, with possible involvement in downstream indole quinone formation 1. TYR localizes to melanosomes and functions alongside tyrosinase-related proteins TYRP1 and TYRP2 to convert tyrosine into melanin pigments that determine human skin, hair, and eye coloration 1. TYR expression is regulated by p53 signaling, particularly following UVB stress, linking melanin synthesis to cellular senescence responses 2. Loss-of-function mutations in TYR cause oculocutaneous albinism type 1 (OCA1), characterized by absent or severely reduced melanin production and associated with optic tract misrouting and reduced visual function 3. Deleterious missense variants (K142M, I151N, M179R, S184L, L189P, C321R) compromise protein stability and enzymatic activity 4. TYR mutations show diverse ancestral origins in admixed populations, with both consanguinity and genetic admixture contributing to albinism risk 5. Crystal structures of related melanogenic enzymes provide platforms for mapping albinism mutations and designing therapeutic inhibitors 1.