Molecular Genetic Diagnostics in the 21st century

The advent of molecular genetic diagnostics has opened up new opportunities in the field of preventative and restorative healthcare.  The newly available genetic diagnostic technologies have given rise to legal and moral conundrums that have not been sufficiently resolved.  Just as the debate on the broader implications of genetic technology continues, the number of patients willing to avail of the technology is also on the rise.  Such trends are witnessed here in the United Kingdom, as elsewhere in the industrialized world.  This essay will discuss the molecular genetic diagnostic techniques that are currently being employed for various medical conditions.  Even as the civil society waits to take full advantage of this quantum leap in medical science, a few scientific, ethical and practical issues remain unaddressed yet.

New genetic technologies promise to radically alter the conventional methods of medical diagnostics.  For constituents of the healthcare industry they offer a commercial opportunity.  The progress that we are witnessing in genetic diagnostics presage a revolution in the way health care industry is organized.  For example, the existing technology allows practitioners to ascertain a patient’s vulnerability to certain hereditary conditions.  Quite soon, diagnostic techniques will advance to a level where genetic tests will indicate who will respond well to a drug, who will respond poorly, and who will suffer adverse reactions.  Researchers at Bristol-Myers Squibb, for instance, “have shown that different individuals have different degrees of responsiveness to the cholesterol-lowering drug Pravachol, depending on which of two variants of a polymorphism encodes the cholesterol ester-transfer protein (CETP)” (Petersen & Bunton, 2002).  In a few other cases, the central issue isn’t the level of patient responsiveness but the risk of a negative reaction to the drug.  To cite a recent example, patients, whose carry mutations in the CYP3A family of cytochrome P450 enzymes, can have fatal cardiac reactions to the antihistamine Seldane if they are also taking the antibiotic erythromycin.  Such discoveries about the dynamic processes of molecular genetics can help Doctors to tailor their prognosis to the needs of the particular patient (Petersen & Bunton, 2002).

Genetic diagnostics can help increase the efficacy of prescribed drugs by identifying which class of drug would be most effective for specific groups of patients.  For example,

“Hypertension can be treated with angiotensin-converting enzyme (ACE) inhibitors and beta-blockers, as well as with calcium channel blockers. But not all patients respond to these medications in the same way: many doctors now tend to prescribe ACE inhibitors and beta-blockers to African-Americans, for instance, because these drugs seem to work more effectively on them. An unidentified genetic trait probably explains such differences, but without proof, physicians must arrive at a course of drug treatment by trial and error. Genetic Diagnostics might provide scientific confirmation, thereby organizing and accelerating the process of matching drugs for all sorts of diseases with appropriate patients or groups of patients” (Rados, 2005).

Genetic Diagnostics is a valuable tool in treating more serious medical conditions like cancer, cardiovascular ailments and diabetes, which require a long-term treatment approach.  In conventional medical practice, the physician will be able to determine the suitability of a particular course of chemotherapy only after a few weeks into the course.  By predicting the right category of drug for the patient, genetic diagnostic techniques can help minimize risk to the patient.  Rheumatoid arthritis is another area, where researchers have recently discovered that patients with certain genetic predispositions “responded positively to a single class of drug than to a highly toxic combination of three classes, the more frequently prescribed therapy” (Rados, 2005).  Yet, we are still only in the initial stages of developing fool proof techniques of genetic diagnostics.

In the year 2001 alone, 180,000 women across the world were diagnosed with breast cancer; and the number has steadily grown in the years since.  Like other life threatening diseases, the successful treatment for each of these women will depend on many factors, the foremost among them being the timing of the diagnosis.  Diagnosed early, most types of cancer can be contained and eventually cured.  It is in this context that genetic analysis comes in handy to expedite diagnostics.  Some of the most advanced techniques for detecting cancers– including lymphoma and leukemia–are based on genetic diagnostics. While CAT scans still have their utility as a diagnostic tool, they are now supported by biopsy analysis techniques that use gene probes to detect in cells cancer-inducing genetic mutations.  In particular,

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