Gene Testing Moves Mainstream

BY JAMES S. BURKHARDT, D.O.
 

A recent article in The Wall Street Journal discussed some future trends in medicine.  One of those areas was in the realm of genetic and DNA testing. 

Genetic tests are tests on blood or other tissue to find genetic disorders.  About 900 such tests are available.  Some of these can detect such diseases and disorders as cystic fibrosis, inherited types of breast cancer, Huntington’s disease and hemophilia, and many more. 

For most of us, the knowledge of gene testing is limited to police television shows where DNA testing is used to determine who the father of the baby is or to convict a criminal of a murder or sex crime. 

The other area that gene testing is familiar to us is with newborn screening.  Newborn screening is the practice of testing every baby for certain harmful or potentially fatal disorders that aren’t apparent at birth. 

For years, genetic testing was limited to hospital or research settings.  Now, new advances have made it possible and practical to perform testing in the office setting.  This enables doctors to specifically and individually treat patients from many conditions.  My practice, Upper Valley Family Care, is the first practice in Miami County to offer such gene testing.  Surely others will soon follow due to its utility and practicability.  

One specific example of practical application is with the medication clopidogrel (brand name Plavix).  There is a gene that controls the conversion from the pill you take to its active metabolite.  Some people have variations in the gene, ZCYP19, that do not convert clopidogrel to an active form.  This may occur in as many as 4% of the population.  By identifying these variations, or mutations, doctors can individualize treatment of their “blood thinner” medication that may not be effective. 

There are genetic pathways that influence or alter how some of us process medications.  Some of the medications include many commonly used drugs such as statin medicines to treat cholesterol, seratonin specific re-uptake inhibitors (SSRIs) to treat depression, and beta blockers to treat blood pressure.

By identifying alterations in enzyme function this gene testing has the potential to truly individualize the approach to treatment for certain medical conditions.  This is an exciting new area of interest as gene testing moves away from the theoretical and into practical application.