Category Archives: Genetics

“Scientific Breakthrough:” Editing Genes in Human Embryos

Publications have been reporting on a recent breakthrough in modern medicine: modifying human DNA in human embryos, without introducing the critically serious disease-causing mutations that were problematic in previous attempts.

Published online Wednesday in the journal Nature, the research is targeted towards assisting families with genetic diseases. The new research experiment utilized a gene-editing technique to correct a genetic defect behind a heart disorder, that can cause “seemingly healthy young people” to die from sudden heart failure. Scientists at Oregon Health and Science University, in conjunction with colleagues in California, China, and South Korea, reported that dozens of embryos were repaired: if those embryos developed, not only would they be disease-free, but also would not transmit the disease to future generations.

This is the first time that scientists have successfully edited genes in human embryos to prevent dangerous disease mutations. Scientists collectively agree that while the research is a major milestone and achievement, the prospect of human genetic engineering has already raised ethical concerns. Mary Darnovsky, director of the Center for Genetics and Society—a watchdog group based in Berkeley—says that it is “a flagrant disregard of calls for a broad societal consensus in decisions about a really momentous technology that could be used for good, but in this case is being used in preparation for an extraordinarily risky application.”

Yet the researchers emphasize that the work is focused on preventing debilitating diseases and disorders, not the creation of genetically enhanced babies. Richard Hynes, a cancer researcher at the Massachusetts Institute of Technology who co-led the committee, says that their report sought to eliminate the technical hurdles, but there will inevitably be “societal issues that have to be considered and discussions that are going to have to happen.”

While the overwhelming consensus is that much more research is required before the method could be tested through clinical trials—which is currently not permissible under federal law—the technique could potentially apply to over 10,000 conditions caused by specific inherited mutations. This includes diseases like Tay-Sachs, Huntington’s, sickle cell anemia, cystic fibrosis, and many others.

Nevertheless, any scientists hoping to continue the work in the U.S. are presented with a host of regulatory obstacles. The research was specifically funded by Oregon Health and Science University, the Institute for Basic Science in South Korea, and a number of foundations, as the National Institutes of Health does not fund any work involving human embryos. Moreover, Congress has prohibited the Food and Drug Administration to consider any research or experiments that involve genetically modified human embryos.

Scientists in Britain have received approval to use CRISPR—the gene editing technology—to edit the DNA in healthy human embryos, in order to further research surrounding normal human development; a team in Sweden has also started similar experiments. Fredrik Lanner, a geneticist at the Karolinska Institute in Stockholm—conductor of the experiments—says that this needs to be highly regulated. “This is very exciting. But it also could be a double-edged sword. So I think we really have to be extra cautious with this technology.”

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Using Genetic Testing to Target Disease

A new study recently published in the journal JAMA Pediatrics indicates that young children with epileptic seizures should be given routine genetic testing.

The study’s lead author Anne Berg, of the Stanley Manne Children’s Research Institute at Lurie Children’s Hospital of Chicago, states: “Precision medicine means nothing without precision diagnosis, and we can now provide precision diagnosis.”

Many researchers and physicians have supported the idea that genetic testing should be incorporated into routine initial evaluations, specifically of young children with epilepsy: the sooner a precision diagnosis is made, the sooner the child can begin effective treatment. Moreover, the level of genetic information provided through testing is extremely successful in helping physicians identify which drugs and treatments are effective, and which to avoid.

Not only does this study reinforce data that could successfully and effectively change epilepsy diagnosis, but it also confirms the idea that precision medicine should be a fundamental part of standard clinical practice.

Yet this is by no means the first study surrounding the idea that genetic testing could potentially transform levels of care, as many conditions have underlying genetic causes. Due to advances in DNA testing technology, clinicians are now able to provide more accurate, precise, and individualized ways to pinpoint genetic variations that lead to disease. Over the past two decades, the number of genetic disorders for which DNA testing is available has increased from about 10 to over 1,000, due to advances in molecular genetics.

For many disorders, genetic testing is the only way to make a completely accurate diagnosis—and avoid additional, unnecessary clinical investigations. With some genetic diseases, a combination of good surveillance and early intervention can decrease the risk of mortality, and be helpful in future family planning. Clinicians who can understand and interpret the data generated by genetic testing will be more able to choose the most appropriate, suitable therapies and support strategies for patients.

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Human Gene Editing

The National Academy of Sciences, in collaboration with the National Academy of Medicine, has lent their support to a “once-unthinkable” proposition: modifying human embryos, in order to create genetic traits that can be transferred to future generations.

Notwithstanding the medical and scientific complications, human gene editing has historically posed an ethical dilemma, as scientists fear that techniques used to prevent hereditary and genetic disease might also be used to create specific physical traits, or enhance intelligence.

A special science advisory group has solely endorsed alternations that are designed to prevent babies from acquiring genes known to cause “serious diseases and disability,” and only when there is no “reasonable alternative.” This engineering might allow people to have children without fearing that they have passed on genetic traits for diseases and disabilities like Huntington’s and Tay-Sachs.

The advent of a specific gene-editing tool called Crispr-Cas9 has allowed researchers to alter, insert, and delete genetic material with rapidly increasing precision, and has spurred plans for experimental treatments of adult patients with conditions like cancer and blindness.

Yet opponents of this new technology argue that human gene line editing will lead to the engineering of traits like beauty, strength, intelligence—ultimately leading to the possibility of a disproportionate divide between those who can afford enhancements, and those who cannot.

There are also questions of safety and autonomy, in addition to social justice and moral concerns. Despite the precision of Crispr, its ‘off-target’ effects include cutting DNA at places it is not meant to—leading to the inadvertent creation of new complications. Furthermore, while the published report prohibited any alternations that resembled ‘enhancement,’ it is not clear where the line is drawn.

Nevertheless, it will likely be years before gene-editing techniques tested in animals can simultaneously work in humans. The Food and Drug Administration currently prohibits the allotment of any federal money to support research that results in genetically modified offspring. This groundbreaking step will likely only be considered and implemented after more research and studies, and only conducted under extremely tight restrictions.

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