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). This evidence concerns the gene ALDH3A1 and Decreased total leukocyte count.