The clinical, biochemical, and molecular analysis of a patient with chronic granulomatous disease (CGD), retinitis pigmentosa (RP), and McLeod phenotype and of his parents demonstrated the X-linked transmission of these three traits in this family and a deletion of the entire X-CGD gene of the patient DNA. All but one other DNA markers tested, including those in Xp21, were present. These findings strongly suggest that the McLeod locus and at least one XL RP gene are closely linked to the X-CGD locus in the Xp21 region of the human X chromosome.