Hereditary Transmission of Exceptional Resistance to Coumarin Anticoagulant Drugs

Abstract
THE variability of response of human beings to many drugs is usually continuous and gives a unimodal frequency-distribution curve for the drug action measured. These unimodal distribution curves are consistent with multifactorial inheritance and are difficult to analyze for the genetic influences involved. The few drugs that have a discontinuous variation in action show a bimodal or trimodal distribution. This probably indicates a single gene system with each mode representing a phenotype1 from which the genotype may be inferred. This multimodal distribution curve of drug response is usually the result of an alteration in drug metabolism and causes increased sensitivity . . .