Pharmacogenetic Testing

Many of my families are asking about pharmacogenetic testing (PGT).  Some families are coming with the results of testing and asking for my interpretation.  I often see a child whose parent had the test and their result can help in my recommendations to the child.  PGT is particularly helpful in antidepressant and antianxiety medication.  The tests are primarily of genes for liver enzymes called cytochrome P450s (CYPs).  We know which CYP chops up which medication.  You can be normal for one enzyme, low for another and high for another.  Other tests are related to serotonin and dopamine receptors.  These can help predict response to certain categories of medication.  Methylfolatereductase (MTHFR) is typically in the panel of tests.  MTHFR is an enzyme that helps folate get into your brain.  Folate is used to help make various neurotransmitters and reduce inflammation in the body.  If MTHFR is low, a client can take a special supplement called l-methylfolate or folinic acid because regular folate in diet or vitamins won't help. 

Pharmacogenetic testing should not be used as the sole determinant for choosing medication.  It will not tell you which medication will work.  The test is more helpful in telling me what not to use or why you got side effects.  The reports are typically simplified into categories of green "use as directed", yellow "use with caution" and red "use with extreme caution".  However, the best medication might be in the red zone.  We just might need to start a very low dose of a medication that you metabolize slowly.

There are multiple companies providing similar tests.  All of them are either oral swabs or saliva tests (no needles).  I have used Genesight and Millenium the most and both are great.  Insurance companies often do not cover this test.  PGT tends to save a lot of trial and error so my hope is that insurance will cover it more often.  The benefit is usually a more targeted approach to medication and less time spent switching between meds.  All of the companies allow you to pay for the test privately for about 250$.  The test comes back in less than a week.