Examination of this gene in 497 patients in the Amazonas State, Brazil, made by the doctor S�rgio Albuquerque, suggests that the genotypes FY * A / FY * B-33 and FY * B / FY * B-33 ( where-33 refers to the null mutation at position-33 in the GATA box ) may have an advantage over the genotypes FY * A / FY * B and FY * A / FY * A, FY * A / FY * B, FY * A / FY * X and FY * B / FY * X . FY * A / FY * B and FY * A / FY * A genotypes showed to be associated with increased rates of " P . vivax " infection and FY * B / FY * X and FY * A / FY * X were shown to be associated with the low levels of parasitism.
