Using genetic information about the individual to pick the right drug for the right disease
at the right dose defines personalized medicine. This pilot study seeks to institute
pharmacogenomic testing, that is identifying genetic variation that influences patient
response to drugs, into the Nemours Children's Health system. We propose to initiate the
study by identifying genetic differences in cyp2c19, a gene that is responsible for a certain
enzyme in the liver that metabolizes many drugs including a class of drugs called proton pump
inhibitors (ppi; Prevacid, Nexium). PPIs are used to treat heartburn and other symptoms of
gastroesophageal reflux disease (gerd) and are extensively used in pediatrics. Chronic use of
PPIs can cause serious side effects including cold, pneumonia and stomach infections, which
gets worse at higher doses. Children who poorly metabolize drugs because of genetic variation
in cyp2c19 should get lower doses of PPIs than children who metabolize PPIs normally. Our
pilot study will genotype children with gerd or other stomach acid mediated conditions for
which a PPI is prescribed using a sample of spit to determine which dose of PPI they get
based on the form of the cyp2c19 gene they have. We will study 120 children 2-17 yo diagnosed
with gastroesophageal reflux disease (gerd) or other stomach acid mediated conditions for
which a ppi is prescribed . Genetic results are available in < 60 minutes, and their doses
are determined by their doctor based on genetic results. This study will allow us to gain
valuable experience that will be used to expand our genetic program to other genes and drugs.