Cytochrome P450 CYP2D6 polymorphism is an autosomal recessive trait associated with impaired debrisoquine metabolism in 5-10% of caucasian populations. This polymorphism has been associated with susceptibility to Parkinson's disease, bladder cancer, various forms of leukemia and possibly melanoma. In many other cancer forms, the data remained contradictory due to the technical limitations for identifying affected individuals (poor metabolizers). A recently developed polymerase chain reaction-based assay allows convenient screening of approximately 80% of known mutations. We have tested brain tumors correlated with chromosome 22 deviations for genetic polymorphism in the cytochrome P450 CYP2D6 locus localized on chromosome 22q13. Thirty-one meningioma samples were analyzed and the observed frequency of heterozygotes and homozygotes for the G to A mutation did not deviate significantly from the distribution in a normal population. These data are comparable to previous observations in for example breast and colon cancer and indicate that the CYP2D6 locus on chromosome 22q13 is not involved in the pathogenesis of meningiomas.