On pages 68, Dr. Moalem
describes “personalized medicine,” where dosing and drugs are tailored
to fit your genome. Personalized medicine commonly denotes the use of some kind
of technology or discovery enabling a level of personalization not previously
feasible or practical. The concept of “personalized medicine” relates to
Big Idea 1 (The process of evolution drives the diversity and unity of life.)
Due to different environmental pressures, human populations have made
adaptations and over time have evolved in order to accommodate to their
environmental pressures.
Define personalized medicine
in your own words and explain the significance of this revolutionary type of
medicine. Compare and contrast personalized medicine with previous methods of human
medicine.
How might your body's response
to the environment differ depending on your ancestry? Explain the factoids of
evidence relating to a particular disease referred to in Survival of the
Sickest or an outside source that show how different populations of people
may have evolved differently in response to their environments and how personalized
medicine would be beneficial to them.
Specifically
research how personalized medicine would be beneficial in the case of the
CYP2D6 gene, a gene that affects the way people metabolize more than 25% of all
pharmaceuticals.
Finally,
relate the idea of personalized medicine to the personal DNA chip mentioned in
Sam Rhine’s Genetics Update Conference.
Research and describe pharmacogenetics and relate this to personalized
medicine. What are the pros and cons of this new “Genomic Era of Medicine?”
(Taylor Young, tyoung3@students.d125.org)
Personalized medicine is a new frontier of medicine being researched and developed across the world. Theoretically, medical prescriptions can be tailored to each individual patient based on a transcript of his or her genome, and new medicines may be designed to cure those with genetic diseases.
ReplyDeleteTraditional medicine works by treating patients as statistics. According to an article on OpposingViews.com (http://www.opposingviews.com/i/understanding-personalized-medicine), in the past “you would be more likely to get well by being treated as a statistic.” The example this article gives is this: if there is a drug that helps 98% of patients with high blood pressure, it will be prescribed to 100% of the patients. The obvious problem is this approach ignores the 2% that may respond better to alternative medication.
Recent medical advancements, however, have paved the way to a new approach to medicine: tailoring drugs to fit the needs of individual patients. Using a DNA microarray, scientists can measure gene expression in a human. The microarray is a glass plate with tens of thousands of indentations filled with complementary DNA. Using reverse transcriptase, scientists can recreate an exon-only version of the patient’s DNA and apply the solution to the microarray. Each DNA fragment bonds to its unique compliment, and a laser is used to determine the concentration of DNA fragments within an indentation; a higher concentration means greater gene expression. If the functions of every DNA sequence can be delineated, a microarray will tell doctors exactly how their patients will respond to certain drugs.
The CYP2D6 gene is one of the most important when it comes to metabolizing pharmaceuticals, and it has great potential to be a key factor when it comes to prescribing medicine. The CYP2D6 gene is located on chromosome 22, section q, in position 13.1, and genetic variation is common from person to person (http://ghr.nlm.nih.gov/gene/CYP2D6). Dr. Moalem describes those with many copies of the CYP2D6 gene as being “fast metabolizers,” or those on whom certain medicines have little effect. If a doctor were to encounter a patient with many copies of this gene, he might not prescribe medicine he knows will be ineffective. If a patient has too few copies of this gene, a doctor would hesitate to prescribe medicine that will build up to dangerous levels in the patient’s body.
A traditional approach to medicine is still practiced on those who suffer from attention deficit disorders; there is a lively debate as to whether American’s are over-medicating their children. Stanford Newmark, president of the pediatric integrative neurodevelopmental program at the University of California, states that doctors make diagnoses with limited medical review and the medicine they prescribe is an extreme solution (http://online.wsj.com/article/SB10000872396390444301704577631591596516110.html). Consumption of drugs like Vyvanse and Provigil has nearly doubled since 2003, and Newmark mentions a host of negative side effects that include decreased appetite, nausea, and insomnia. Personalized medicine has the potential to help in this field. Using DNA microarray to assess a patient’s phenotype can help doctors not only in making an accurate diagnosis, but in prescribing the right medicine to a patient. If GWAS (Genome Wide Association Studies) can pinpoint the nucleotide sequences that increase the risk of ADD, diagnoses can be made with more certainty. Equally important, other nucleotide sequences – such as the CYP2D6 gene – will tell us whether or not a patient will respond positively to a certain drug, or if it is better to avoid medication altogether.
--Aidan Murphy, Amurphy4@students.d125.org