Single-gene pharmacogenetics

McLeod, H. L. (2004) Drug pathways moving beyond single gene pharmacogenetics. Pharmacogenomics. 5, 139-141. 

Single Gene Pharmacogenetic Studies in Genes Influencing Disease Progression, 636... 

Many Pharmacogenetic Polymorphisms are Exceptions to Experience with Single Gene Disorders... 

In these scenarios, the allele frequency of the variant is not considered to be different between the disease cohort and an appropriate control population. However, the hypothesis being tested is whether the polymorphism is associated with some relevant clinical characteristic, a defined phenotype, or a clinical subset of a heterogeneous syndrome. As discussed earlier, it may be difficult to ascertain disease risk when a variant from a single gene is one of several from multiple genes that together ascertain risk. Furthermore, disease modification effects may be part of a pharmacogenetic influence. In many cases, it is not ethical to withdraw or standardize therapy for all patients, so statistical methods need to be utilized to ascertain medication use as a confounder in analysis of a polymorphism s disease modification potential. 

The pharmacogenetics approach is very well suited to solve the problems of single-gene (Mendelian or monogenic) disorders. 

As described previously, pharmacogenetics began with the study of single gene differences between individuals but developed into a broad science. Methodological advances expanded the science further into pharmacogenomics one... 

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