CYP2D6 and malaria: For instance, the CYP2D6*4 allele was observed at a frequency of 14% in an urban admixed population from Aragua, a nonmalaria state, and in Amerindian populations at frequencies of 4.2%–42.5% from Zulia (nonmalaria state) and 1.7%–5.45% from Bolivar (malaria state).