The historical perspective of pharmacogenetics is presented to a large exte
nt from a personal view since I happened to get into this field of science
at the time of its beginning, and since pharmacogenetics has remained the b
ackbone of my scientific career. Pharmacogenetics initially emphasized obse
rvations of interpersonal variability, but the attention on interethnic dif
ferences soon followed. Technical advances led to the identification of man
y responsible gene alterations in both individuals and in populations. Incl
uded is a relatively extensive discussion in which the effects and the diff
erent consequences of monogenic (mendelian) and multigenic (multifactorial)
variation are compared.