The primary goal of the "Molecular Characterization of HLA-DR and -DQ Genotypes Associated with Susceptibility to Vitiligo" is to resolve, at the DNA level, HLA-DR and -DQ haplotypes associated with susceptibility to vitiligo in African Americans. Molecular typing methods will be used in this project to refine serologically defined HLA phenotypes associated with disease susceptibility in the target population. Lymphocytes from peripheral blood samples of the patients' family members will be HLA- phenotyped in standard microcytoxicity assay to determine haplotypes. Thus, the molecular characterization of HLA-DR and -DQ haplotypes at the DNA level will not only define the definition of disease-associated alleles and/or sequences, but also be of great importance in better understanding the significance of immunogenetic factors in the etiology and pathogenesis of vitiligo in patients with an autoimmune-type disorder.