GENOMICS AND PERSONALISED MEDICINES:
As each individual has a unique genome, genetic disorders are also unique for a particular patient in most of the cases. It is possible to identify the regions of mutation if the sequence of a patient’s DNA is known. These mutations can then be corrected by gene therapy. The gene therapy provided will obviously be unique to each patient. Hence, these are known as personalised medicines.
In personalised medication, apart from a medicine’s effect on a disease, medication is also given on the basis of their interaction with the patient’s genome.
HOW DID PERSONALISED MEDICINE GAIN MOMENTUM?
In 1902, Sir Archibald Garrod made the first connection between genetic inheritance and susceptibility to a disease (called alkaptonuria). About half a century later, in 1956, the first discovery of a genetic basis for selective toxicity was made (for the antimalarial drug primaquine). In 1977, the discovery of cytochrome P450 metabolic enzymes and their role in chemically altering drugs so they can be eliminated from the bloodstream led to the realization that variation in these enzymes can have a significant influence on the effective dose of a drug. Yet, the real drive towards personalized medicine began in 2003 with the complete sequencing of the human genome. We are now moving beyond the genome into the entire spectrum of molecular medicine, including the proteome, metabolome, and epigenome.
IDENTIFYING AND TREATING CANCERS
Genomic information has “opened our eyes” to the diverse characteristics of cancers and helped inform advances in drug development.
Cancer in two different individuals is not always same, there may be some part of the sequence of specific cancer in a particular patient that makes it different from the cancer of another patient. This explains why chemotherapy isn’t successful for all cancer patients. – “More and more in what we’ve learned is that tumours have certain mutations in common that make them more responsive or non-responsive to chemotherapy.”
Advances in genomic and genetic screening can also help identify the presence of cancer, particularly cancer recurrences, earlier and with less invasive methods. And help medical practitioners assess a specific individual’s health risks.
CHECKING THE RECURRENCE OF CANCER:
Often, the only way of diagnosing the recursion of cancer is through X-ray or an MRI. Or undergo unpleasant procedures like cystoscopy. But with advancements in the field of genomics, now, there are tools where, for instance, you look at the cancer cells in the urine, The urine test, which measures three distinct DNA methylation markers, detected tumor recurrence with both high sensitivity and specificity (80% sensitivity and 97% specificity) in NMIBC patients.
Health care systems, more and more, are setting up sequencing facilities, or turning to independently owned facilities, to conduct this type of work.
ADVANTAGES OF PERSONALISED MEDICATION:
Personalised treatment has turned out to be a great boon as it:
- Shifts the emphasis in medicine from reaction to prevention
- Directs the selection of optimal therapy and reduce trial-and-error prescriptions
- Helps avoid adverse drug reactions
- Increases patient adherence to treatment
- Improves quality of life
- Reveals additional or alternative uses for medicines and drug candidates.
DEVELOPING AN ETHICAL AND LEGAL FRAMEWORK FOR GENOMICS
As this work continues to jump from academic research labs into the mainstream, certain ethical, legal, and policy implications arise. We do have a number of policies around the globe for the same reason.
If it is known that someone is genetically predisposed to a certain disease, it could lead to employment and insurance discrimination. To avoid this situation, United States has the Genetic Information Nondiscrimination Act that aims to protect people against such a discrimination.
And there are many other propositions like:
- There are challenges we have to be aware of in terms of what information we want to know about our genome and what kind of information is not ready for us to learn about – for instance when there is nothing to do for someone who has a predisposition to a devastating disease.
- Also, policies should be established surrounding who has the right to make decisions based on our human genome.
- Issues such as privacy, informed consent, and intellectual property all come into play as genomic research and technology move forward.
- Accessibility is another techno-economical issue. There’s still a long way and a lot of work to do in bringing technologies to a lower cost, so they are accessible to everyone.