Human Diversity, Genes, and Medicine - Brutes or Angels: Human Possibility in the Age of Biotechnology - page 145

nerable to severe reactions to carbamazepine. A simple genetic test can de-
termine whether a person carries the hlA-B*1502 gene.
To summarize, it is apparent that human health could be enormously im-
proved by better health habits and expanded access to high-quality health
care, including regular exams, screening and diagnostic procedures, and
disease treatment. however, causes for some diseases, and probably the ef-
ficacy of some medicines, have strong genetic components, and these ge-
netic components often distribute themselves unequally across the spec-
trum of human diversity.
Pharmacogenomics
A 2006 report listed adverse drug reactions as the fourth leading cause
of death in the United states after cancer, heart disease, and stroke. The
branch of pharmacology called pharmacogenomics takes genomic informa-
tion about individuals or groups of persons and uses it to design more per-
sonalized and safer drug treatments. one advantage of personalized, ge-
nomic medicine is its potential to reduce the risk of adverse drug reactions
and optimize drug therapies by tailoring diagnostic protocols, drug treat-
ments, and preventative medicine to the genetic makeup of the patient.
Diagnosis, therapy, and prognosis for breast cancers epitomize an es-
pecially fruitful collaboration between genomics, pharmaceutics, and the
clinic. Breast cancer is not just one disease. There are many subtypes and
risk groups of breast cancers that manifest themselves in differing g ene ex-
pression patterns in tumor cells (foekens et al. 2008). To establish which of
the twenty thousand to twenty-ive thousand genes in the human genome
are active in a tumor cell biopsy, clinicians use a gene expression microarray.
This powerful laboratory technology makes use of the fact that an rnA
molecule (or its complementary DnA) will bind specifically to DnA frag-
ments with base sequences like those in the gene from which the rnA was
transcribed. 9 To perform a gene expression microarray test, technicians
first attach thousands of microscopic samples of DnA, each representing a
different gene, to a glass surface. The DnA-spotted surface is then exposed
to fluorescently labeled molecules representing all of the rnAs produced