Coronary Artery Disease: Evidence of Interaction between PTPN22 and p53 Genetic Polymorphisms

Objectives: We recently reported an association between the PTPN22 genetic polymorphism and coronary artery disease (CAD) in nondiabetic subjects. Since recent studies suggest that p53 may be involved in coronary atherosclerosis, we have investigated a possible interaction between PTPN22 and p53 codon 72 genetic polymorphisms regarding their effects on susceptibility to CAD in nondiabetic subjects. Methods: The genotypes of p53 codon 72 and PTPN22 were determined by DNA analysis in 128 nondiabetic subjects with CAD, 122 healthy blood donors and 117 nondiabetic subjects with cardiovascular diseases without CAD. Results: In subjects with the *Arg/*Arg genotype of p53 codon 72, no association was observed between CAD and PTPN22. However, this association was very strong in subjects carrying the *Pro allele of p53 codon 72. Subjects carrying both the *T allele of PTPN22 and the *Pro allele of p53 were overrepresented in CAD nondiabetic cases relative to the other two groups (p = 0.001). Conclusions: Since both p53 and PTPN22 are involved in autoimmune inflammation, an interaction between the two systems appears biologically plausible. In the analysis of multifactorial disorders, the simultaneous analysis of multiple genes functionally related to diseases will provide a more productive approach than studies of single genetic factors performed from a Mendelian perspective.