Background: Oculocutaneous albinism (OCA) is a genetic disorder of the melanin pigment system in which melanin synthesis is reduced or absent in the skin, hair, and eyes. OCA is classified into two major types, and tyrosinase-related OCA can be produced by mutations of the structural gene for tyrosinase enzyme (TYR gene). Objective: The purpose of this study was to analyze the segregation of mutant alleles of the TYR gene in tyrosinase-negative and tyrosinase-positive Korean OCA patients and families. Methods: We amplified exon I, II, and III of the TYR gene of Korean OCA patients and their families by polymerase chain reactions (PCR), and analyzed the mutations by restriction fragment length polymorphism (RFLP) analysis in exon I and single-strand conformation polymorphism (SSCP) analyses in exon II and exon III. Results: Two tyrosinase-negative cases showed mutations in exon I. Four tyrosinase-nega-tive cases and one tyrosinase-positive case showed mutations in exon II, and one tyrosinase-neg- ative case showed mutations in exon III. In summary, we found three kinds of mutation in four tyrosinase-negative OCA patients and one tyrsinase-positive OCA patient. Conclusion: RFLP and SSCP analysis can provide a basis for a rapid and sensitive screening system to detect TYR gene mutations of Korean OCA patients and their families. (Ann Dermatol 9:(3) 182-187, 1997).