Both of them changed the risk about twofold – OR 1.93 (95% CI 1.13–3.31; p = 0.016) by variant allele G of p.Pro329Ala in ALDH3A1 gene (rs2228100) and OR 1.96 (95% CI 1.13–3.36; p = 0.014) by CYP2C19 c.-806C>A (rs12248560) common homozygote CC (Supplementary Table 1).The results of cumulative analysis done for overall leukopenia revealed strong progressive rise of its risk with growing number of unfavorable factors (Table 1). The gene discussed is CYP2C19; the disease is Decreased total leukocyte count.