157An alternative to prospective controlled clinical trials is simple examination of a
treated population in a clinic by retrospective genotyping. This would reveal indi-
viduals that had received treatment by chance from those where it would have been
recommended on basis of genotype as well as individuals that received inappropri-
ate treatment. This approach could produce valuable data to support the value of
pharmacogenomic testing.
Current Status and Future Prospects of Pharmacogenomics
There is an ongoing process of identifying the common, biologically relevant SNPs,
in particular those that are associated with the risk of disease and adverse drug reac-
tion. The identifi cation and characterization of these SNPs are necessary before
their use as genetic tools. Most of the ongoing SNP related studies are biased delib-
erately towards coding regions and the data generated from them are therefore
unlikely to refl ect genome wide distribution of SNPs (Katara 2014 ). Single SNP
association testing is suboptimal given the complexities of the clinical trial setting,
including: (1) relatively small sample sizes; (2) diverse clinical cohorts within and
across trials due to genetic ancestry (potentially impacting the ability to replicate
fi ndings); and (3) the potential polygenic nature of a drug response (Kohler et al.
2014 ). The authors of this proof-of-concept study propose a shift in the current
paradigm to consider the gene as the genomic feature of interest in pharmacoge-
nomics discovery. Genomic region-based association testing has the potential to
improve the power of detecting single SNP or complex pharmacogenomic effects in
the discovery stage and to improve power in the replication stage.
Even, the full potential of currently available data about pharmacogenomics is
largely unrealized because of the logistic challenges in obtaining suitable genomic
information in a timely manner to guide prescribing. Placing genomic information
in the electronic medical record would facilitate personalized medicine. If the
patient’s entire genome were part of his or her medical record, then the complexities
of acquiring a DNA sample, shipping it, and performing laboratory work would be
replaced by a quick electronic query. Although this scenario holds great promise,
the utility of genomic information for drug prescribing must be documented with
rigorous evidence.
The fi rst marketing authorization of a NGS platform (Illumina’s MiSeqDx) for
clinical use in November 2013 will expand the incorporation of genetic information
to improve health care. The approval of NGS is only the beginning. There are many
challenges ahead before personalized medicine can be truly embedded in health
care (Collins and Hamburg 2013 ). There is a need to continue to uncover variants
within the genome that can be used to predict disease onset, affect progression, and
modulate drug response. New genomic fi ndings need to be validated before they can
be integrated into medical decision making. Doctors and other health care profes-
sionals will need support in interpreting genomic data and their meaning for indi-
vidual patients. Patients will want to be able to talk about their genetic information
Current Status and Future Prospects of Pharmacogenomics