What your doctor can't tell, the DNA can
Posted by Dr.C. Srinivasa Raju on April 7, 2016
It’s far more important to know what person the disease has, than what disease the person has. – Hippocrates.
Now we can decipher, as the humans experience different factors in different ways, the nature of diseases is as individual as the people who have them. With the help of genetic, genomic and clinical info, we can predict or identify, about the person's susceptibility to developing any disease and course of disease and its response to treatment. DNA polymorphism decides, how drugs are absorbed and used and metabolized by the body. We know, some genetic or inherited diseases are due to either monogenic disorder or polygenic disorder. We also know, Biomarkers are specific protein molecules associated with specific disease. Analysis of biomarkers helps us to identify sub-types with in a disease and sub-groups of the patients with same disease.
We know, healing is not completely belonged to genre of science. Yes, you know why? It’s because of variability among individuals, which is due to natural genetic variations. That’s why the healing remained as an art". But don’t assume that genome is destiny maker. It tells us what we are- what we would be- they are like sign posts. We have to understand and have to take necessary preventive steps like life style modulation, food intake, choosing proper medications that would benefit without causing any side effects.
The story starts 2 decades back and culminating in to historical sequencing and complete mapping of human genes by the year 2003. Thanks to advanced technologies, the cost of genome sequencing comes down drastically and we reached a stage where we are using the genome analysis as screening tool.
Thanks to rapid advances in DNA-sequencing technology since then, scientists can now sequence a human genome in a few days for well under $1000, and the cost continues to fall rapidly. We have genes for every specific purpose. The genes decide how you look and how your hair would be! Not only that, how you respond and metabolize various foods and medicines. Some people have such genes those facilitate to easily metabolize alcohol, caffeine and aspirin. Those people having such a type of genes they can tolerate lactose in the milk and salt. If we have to assimilate iron and folic acid we need those genes helping that process. The disease risks are based on the predispositions written into our genome at birth, combined with our lifestyle and environment. In the case of cancer, the disease has its own genetic makeup, lending each tumor a unique character with unique tendencies and vulnerabilities. Providing “the right patient with the right drug at the right dose at the right time.”
It’s not personal medicine. Its personalized medicine. "Medicine based on genetic makeup.” The National Human Genome Research Institute defines as, personalized approach to medicine includes an “individual’s genetic profile to guide decisions made in regard to the prevention, diagnosis, and treatment of disease.” We can test the genome for any mutations. As per the mutations report, we can plan the treatment and we can give advice about suitable lifestyle. Knowing your genome or the molecular basis of your disease can be an important piece of evidence for doctors seeking the most favorable treatment plan for you. In the case of cancer, genetic tests could lead to successful drug treatment rather than radical surgery. For instance, melanoma can be BRAF positive, meaning the tumor has a specific gene mutation that sets it apart from other melanomas. Your lung cancer can be EGFR or ALK positive. Your colon tumor may be KRAS positive. Personal Genomics Test help you decode your genome and help you understand what food, lifestyle and other factors that are best suited for your body. Personal Genomics is the next generation healthcare test which not only detects any disease even before you get it but also tells you with high probability your risk of getting that disease and also how to avoid/ reduce your risk of getting that condition.
• A Cancer Genomics test identifies and evaluates your genetic profile and suggests the optimum treatment option. A Cancer Genomics Test helps you to identify optimum treatment option for you and predict the occurrence of unwanted toxicities leading to side-effects.
• Latest NCCN guidelines recommend testing for 15 gene alterations for lung cancer, on the basis of which your treatment can be personalized. It’s also proven fact, that 70% of patients who are not benefiting from conventional chemotherapy can avoid the above side effects with Cancer Genomics test. With cancer genomics test you can get rid of the “trial and error” approach and get to right line of treatment. More than 70% of patients fail to respond to a conventional treatment. Cancer genomics test may help you get the most accurate treatment, which may be cheaper than conventional treatment options. For example, if you have EGFR gene mostly active in lung cancers, a significantly low cost treatment of a targeted drug works better than expensive chemotherapy, reducing the cost up to 90%.Cost of management of side effects due to chemotherapy accounts for additional 25% to the cost.
Off late we came to know there are no hard and fast rules in Medicare. Consumption of Poly Unsaturated Fatty Acids is usually recommended to reduce risk of heart disease. Is it right? Now with genome analysis, it’s not always correct.
We know that women with A/A genotype in apoE1 gene will have increased HDL (good cholesterol) on consumption of PUFA, while those with G/G genotype will have a harmful reduction in the levels of HDL (good cholesterol).
How the patients respond to coffee and aspirin also depend on genetic makeup.
Carriers of Met/Ile and Met/Met genotypes in the LPA gene have a 56% reduction of heart disease with aspirin therapy; Ile/Ile carriers experience no benefit from aspirin therapy.
Carriers of different polymorphisms in the CYP1A2 gene have different results from consuming coffee. Those with A/A genotype are recommended coffee to reduce their risk of a heart attack, while those who have either the A/C or C/C genotype will incur a higher risk of a heart attack, therefore avoid consuming coffee.
Researchers have discovered more than 1,800 disease genes since the Human Genome Project’s completion. There are now more than 2,000 genetic tests for human conditions and 350 biotechnology based products currently in clinical trials. Ethical and practical challenges about privacy, access, ownership, and more.
What are the advantages with personalized medicine (PM)?
- Ability to make more informed medical decisions
- Higher probability of desired outcomes thanks to better-targeted therapies
- Reduced probability of negative side effects
- Focus on prevention and prediction of disease rather than reaction to it
- Earlier disease intervention than has been possible in the past
- Reduced health care cost
PM is already having an impact on patient treatments:
- Molecular testing is being used to identify breast cancer and colon cancer patients likely to benefit from new treatments
- Newly diagnosed patients with early stage invasive breast cancer can now be tested for the likelihood of recurrence.
- Using natural genetic variations PM aims to develop new safe and effective treatments for genetically defined sub- groups of patients.
Personalized therapy closer to reality.
We have to understand how diseases affect people differently.
The current "one-size-fits-all" approach to healthcare, in which there are standard treatments for single conditions, means that many patients take medication that does not improve their symptoms.
A newly-developed digital map detailing different mechanisms that contribute to the development of asthma has opened the door to personalized treatment more targeted to the type of asthma patients live with.
In other disease areas, the Parkinson's disease map and the Atlas of Cancer Signaling Network, have already begun the process of integrating knowledge about the involved mechanisms in order to understand the different subtypes of these diseases. The Asthma Map is the first detailed representation of the different molecular processes involved in asthma.
Fast and cheap DNA sequencing is critical to the adoption of genomic-based personalized medicine. It allows scientists to locate in each of our genomes the genetic variations responsible for many diseases and conditions. Whole-genome analysis of these variations in each patient will enable doctors to practice more predictive, preventive and precise medicine, resulting in better health. Personalized Medicine Is Impacting Patient Care in Many Diseases and the age of future medicine is just arrived.
Hello! I want to know my future! You….?