Summary

Mukherjee explores three case studies to "illustrate the power and the peril of using genes to predict 'future risk'" (437). The first focuses on the breast cancer gene BRCA1 which increases a woman's chance of developing the cancer by 80 percent. However, there are many variables about the type and severity of cancer that may or may not develop. Awareness that one is a carrier of the gene then prompts a series of further questions for the individual about how to deal with that knowledge and whether (or how) they want to explore prophylactic treatment options.

The second case study brings Mukherjee's narrative full circle with a discussion of schizophrenia and bipolar disorder. He writes about the difference between familial and sporadic schizophrenia and highlights the complexity of genes likely involved in its occurrence. Furthermore, he notes the frequent association between certain...