Introduction: the CYP2D6 gene is highly polymorphic and is involved in the metabolism of a wide variety of drugs and xenobiotics. Three allelic variants of the gene (rs3892097, rs1065852 and rs28371725) have been studied in relation to breast cancer, but the degree of genetic linkage between them is unknown. Objetive: to test whether the three breast cancer-associated SNPs are inherited en bloc. Methods: genotypes of 280 SNPs of the CYP2D6 gene were obtained from the 1000Genomes database and linkage disequilibrium between the three breast cancer-associated SNPs and the other 277 SNPs in the gene was analysed. A threshold of r2= 0,7 was used to identify loci in linkage disequilibrium. Results: a strong correlation was found between rs3892097 and rs1065852 in Europe and Latin America. In addition, eleven polymorphisms with a high level of linkage were identified, four of which have a non-synonymous mutation effect. Conclusions: both polymorphisms could have a causal effect on breast cancer or that one of them is associated by linkage. Continuing to study both polymorphisms and considering the eleven new polymorphisms for analysis would be of relevance to deepen knowledge in relation to breast cancer in women.