Studies in North Indians with RHD suggest that the (PTPN22) haplotype, which encodes an important negative regulator of T-cell activation, modulates the risk of developing RHD.41 In a Turkish population, however, it was demonstrated that the PTPN22 R620W polymorphism was not associated with RHD,49 showing that genetic differences exist among populations from different regions of the world, therefore making it relevant to implement similar studies in Africa. The gene discussed is PTPN22; the disease is rheumatic heart disease.