Personalized Medicine

• By Ericka Hendrix, Ph.D.
• April 30, 2019

Imagine a world where health care is based on who you are and what health needs you have as an individual versus health care designed for all people in general.
 
Precision medicine is changing the way doctors prescribe medicine. Diagnostic molecular scientistsare working towards this medicine, where medicine is catered to you—all because of an individual’s genetics. We all have different genetics. And it makes perfect sense that each human being will respond differently to disease and treatments. This is what molecular pathologists are researching and working towards. The goal of all of this detailed knowledge is to make better outcomes for the patient.
 
Take for example redheads who have a dental procedure done. There are published studies that Novocain does not work in the same timeframe for redheads as it does for other patients who are having dental work done. The drug’s effectiveness does not kick in for them for almost an hour. The research showed many dentists know now to allow a redheaded patient to sit 30 minutes longer to allow the medicine to take its full effect. A person may metabolize a drug differently than someone else based on their genetics. In some cases, especially pediatric patients, even Tylenol can act differently with each person. The drug can build up in the young patient’s system. If it is given to the patient every four to six hours, they cannot metabolize it. The hope with molecular diagnostics is that the patient’s individual genetic information will be used to change the way health care providers prescribe medicine.
 
Scientists also diagnose diseases based on DNA. Genotype is your complete heritable genetic identity, and it is used to sequence the DNA from a person to find out if they have a genetic disease. Genotyping takes the DNA, isolates it and then sequences it to tell us if the gene is working properly or not. And if there is a single nucleotide polymorphousor (or what we call SNPs) that's incorrect, it can cause disease. Molecular pathologists look for mutations that are not normal in the DNA sequence.
 
You may have seen the genealogy DNA services available for the public. Scientists use this same technology to diagnose disease. The technology is used to detect genetic diseases in a person. For example, if a pathologist gets a biopsy of a cancer sample, they can sequence it because cancers have certain genotypes. They have a gene that was turned on or turned off due to a mutation, and that causes the growth of the cancer. Pathologists also can monitor the cancers evolution because cancers change their genome type over time. The hope in the near future is to use this science in order to work with doctors to figure out which drugs better treat cancer patients and one day eradicate cancer.
 
The science also has changed how we test samples. Now we can draw blood samples instead of having to get a biopsy because there is a circulating tumor DNA in your blood. The procedure is called liquid files and is less invasive then a surgical procedure. This is a new area that will change how testing is done in the future.
 
The science is revolutionizing the turnaround time in the laboratory from when you get a sample drawn, and being able to detect pathogens quickly. The traditional way of
detecting microorganisms is to take a swab of a person's affected area, display it on a plate and grow it for a few days. But with molecular testing, that same swab can be run through a molecular test. The sample can be tested for 19 different organisms in one and a half hours. There are some organisms that still have to be grown and cultured, but now these tests can be done quickly.
 
Hopefully with more answers, health care professionals can change health outcomes.
Scientists are working to change how disease is treated in the future and how to edit genes to eradicate disease.
 
Ericka Hendrix, Ph.D., is the School of Health Professions program director of the Texas Tech University Health Sciences Center Molecular Pathology Program.