How personalized medicine became genetic, and racial: Werner Kalow and the formations of pharmacogenetics.

Physicians have long puzzled over a well-known phenomenon: different patients respond differently to the same treatment. Although many explanations exist, pharmacogenetics has now captured the medical imagination. While this might seem part of the broader interest in all things genetic, the early history of pharmacogenetics reveals the specific factors that contributed to the emergence of genetics within pharmacology. This paper examines the work of one pioneering pharmacologist, Werner Kalow, to trace the evolving intellectual formations of pharmacogenetics and, in particular, the focus on race. Working in the 1950s and 1960s, Kalow made three arguments to demonstrate the relevance of genetics to pharmacology, based on laboratory techniques, analogies to differences between other animal species, and appeals to the logic of natural selection. After contributing to the emergence of the field, Kalow maintained his advocacy for pharmacogenetics for four decades, collecting more evidence for its relevance, navigating controversies about race and science, and balancing genetics against other possible explanations of patient variability. Kalow's work demonstrates the deep roots of the genetic and racial preoccupations in pharmacology. Understanding this history can restore attention to other explanations of individuality in medical practice, something of increasing importance given the current interest in personalized medicine.