Twenty informative families have been studied. and linkage between the tyrosinase-positive oculocutaneous albinism locus and the beta-globin locus has been excluded with a maximum lod score of -9.85 at 0 = 0.05. In lower mammals there is linkage between the p locus (considered to be equivalent to the human tyrosinase-positive oculocutaneous albinism) and the beta-globin locus.