Past studies showed that people with certain inherited traits might be more sensitive to benzene exposure. This new study looked at genetic traits in three genes that influence the way that benzene is processed when it gets into the body. When exposed to benzene, workers with two of these genetic traits tended to have lower white blood cell counts than workers without, so that benzene did have a stronger effect on workers with certain inherited differences in these genes. In particular, the study found that people with the more common version of the MPO gene were more susceptible to the effects of benzene on white blood cell counts.
This answer is based on source information from the National Cancer Institute.