Monday, April 25, 2016

Gene Editing: Science's Brave New Frontier

A single genetic error is blamed for crippling disorders, such as sickle-cell anemia, Huntington's disease and muscular dystrophy. Scientists long ago identified the defective genes responsible for each of these calamities, but have been unable to capitalize on that knowledge.

That may soon change with the discovery of a new method to edit the genetic code.  At its basic level, the cutting-edge tool potentially will allow doctors and scientists to edit out unwanted disease-causing genes. Imagine new generations of babies born without these genetic defects.

Although it is an oversimplification, the new technology is like using the "delete" button on your computer keyboard to remove a word.  In this case, the gene is removed as easily as correcting a typographical error. It opens up a new frontier for making some diseases extinct in the future.

The pioneering discovery was publicly unveiled about four years ago when scientists realized a protein could be deployed to facilitate gene editing.  The protein acts as a pair of scissors, snipping out pieces of viruses or faulty DNA.  In addition, it enables the cell to knit itself back together.

The scientific name for the gene editing process is CRISPR-Cas9. CRISPR is an acronym for "clustered regularly interspaced short palindromic repeats,"a description of repeating sequences of genomes.  Cas9 is the protein that enables the gene editing.

Without diving too deeply into the science, envision a cellular scalpel that is guided through a complex web of genomes until it locates the precise flawed gene. Scientists believe this technology will usher in a new era in biology research, medicine and biotechnology.

Although other gene editing procedures exist, researchers have found that CRISPR-Cas9 is simpler, faster, cheaper and more accurate.  That is part of the technology's allure, which scientists believe may make it possible to address complex maladies, such as cancer, which involve hundreds of genes.

Using the science, doctors could potentially eliminate or add genes in human embryos, sperm or egg cells to correct a mutation that otherwise would promote the development of a debilitating disease leading to a lifetime of suffering and expensive medical treatment.

The heritable gene alterations made in humans would be passed on to future generations.  It is plausible to believe that the technology could transform evolution itself as heritable genes for certain diseases are forever eliminated from a family's lineage.

Dr. George Church, a professor of genetics at Harvard Medical School, urges prudence to avoid unintended consequences.  "If a new technology is an improvement over previous practice, then we cautiously implement it for the clearest needs first, watching for opportunities to make it even safer," he wrote in The Wall Street Journal.

The Harvard educator suggests beginning with a focus on repairing the most deadly, incurable genetic diseases in newborns.  If these trials yield safe, effective results, then Dr. Church advocates moving to other undesirable heritable traits.  

However, the prospect of gene-editing is not without ethical concerns, especially because of its intended use on embryos.  It conjures up images of designer children, programmed with genes for intelligence, hair color, stature and other desirable characteristics.

That kind of genetic tampering raises eyebrows in the scientific community.  Already, Chinese scientists have successfully genetically modified monkeys in the embryonic stage.  Another Chinese team pushed the limits further, experimenting with editing genes in human embryos.

However, there are other non-human applications for the genetic technique. For example, it could be used to alter genes in plants to guard against fungus or to develop drought-resistant crops. Even this function, however, has sparked debate about the use of technology to genetically alter foods.

No doubt there needs to be more study about gene editing applications. But the implications for a future free of human disease, punishing disorders and misery is too encouraging to hamstring the progress of trials.  Not to forget, the impact on medical expenses for treating the diseases.

The science will remain unproven until carefully monitored, ethical human experiments are green-lighted. America should be at the forefront of this new frontier, leading instead of standing on the sidelines and complaining about the nefarious intentions of others.    

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