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The East African : Feb 25th 2017
28 OUTLOOK The EastAfrican FEBRUARY 25 - MARCH 3, 2017 DEVELOPMENT Human gene editing gets key panel’s support The onceunthinkable p≥oposition has been seen as an ethical minefield By AMY HARMON New York Times News Service A n influential science advisory group formed by the National Academy of Sciences and the National Academy of Medicine last week lent its support to a once-unthinkable proposition: The modification of human embryos to create genetic traits that can be passed down to future generations. This type of human gene editing has long been seen as an ethical minefield. Researchers fear that the techniques used to prevent genetic diseases will also be used to enhance intelligence, for example, or to create people physically suited to particular tasks, like serving as soldiers. The advisory group endorsed only alterations designed to prevent babies from acquiring genes known to cause “serious diseases and disability,” and only when there is no “reasonable alternative.” So-called germline engineering could allow people to have biological children without fear that they have passed on the genes for diseases like Huntington’s, Tay-Sachs and beta thalassemia, and without discarding embryos carrying the mutations, as is often done now. The new report heralds a day scientists have long warned is coming. “It is essential for public discussions to precede any HOW IT WORKS The advent of a powerful gene-editing tool called CRISPR-Cas9 allows researchers to snip, insert and delete genetic material with increasing precision. It has led to plans for experimental treatments of adult patients with cancer, blindness and other conditions as early as this year. But these types of genetic alterations are not inherited. Fo≥ diabetic women, hea≥t disease a wo≥≥y By MARLENE CIMONS The Washington Post Women typically don’t develop heart disease — or high blood pressure, one of its major risk factors — until after menopause. But “if you have diabetes, that rule no longer applies,” says Christine Maric-Bilkan, a programme officer in the vascular biology and hypertension branch of the US National Heart, Lung and Blood Institute. Diabetes “dramatically increases the risk” of heart disease at any age — overall, people with diabetes are twice as likely to have heart disease or a stroke as are other people — and its impact “tends to be greater in women than in men,” she says. Diabetes, a disease in Germline engineering could allow people to have biological children without fear that they have passed on genetic diseases. Picture: File decisions about whether or how to pursue clinical trials of such applications,” said R. Alta Charo, a bioethicist at the University of Wisconsin-Madison and a leader of the panel that wrote the report. Just over a year ago, an international group of scientists declared that it would be “irresponsible to proceed” with making heritable changes to the human genome until the risks could be better assessed and until there was “broad societal consensus about the appropriateness” of any proposed change. No one is pretending that such a consensus now exists. But in the year that the committee was deliberating, Charo said, the techniques required to perform this sort of gene editing have passed crucial milestones. “Previously, it was easy “We see a path where gene editing is possible; we have to make sure it’s used for the right things.” Richard Hynes, Massachusetts Institute of Technology for people to say, ‘This isn’t possible, so we don’t have to think about it much,’” said Richard Hynes, a cancer researcher at the Massachusetts Institute of Technology, who helped lead the committee with Charo. “Now we can see a path whereby we may be able to do it, so we have to think about how to make sure it’s used only for the right things.” A more pragmatic concern driving the committee was the likelihood that the new technology would be adopted, in countries like China, where some pioneering research on editing human embryos — without the intent to gestate them — has already occurred. But opponents of human germline editing say that is not a reason to take a crucial step toward what they fear will be an inevitable push to engineer traits like strength, beauty and intelligence, perhaps eventually creating a dystopian social divide between those who can afford such enhancements and those who cannot. “This opens the door to advertisements from fertility clinics.... And whether these are real advantages or perceived advantages, they would accrue disproportionately to people who are already advantaged,” said Marcy Darnovsky, executive director of the Centre for Genetics and Society, a public interest group in California. No one should expect to design a baby anytime soon. It will most likely be several years before gene-editing techniques tested in animals can be shown to work in humans. which the body either doesn’t produce enough insulin (Type 1) or cannot use it properly (Type 2), can cause spikes in blood sugar. Over time, these spikes can damage nerves and blood vessels, putting diabetics at elevated risk of heart disease and stroke. Uncontrolled diabetes also contributes to vision loss, kidney failure and amputations, according to the National Institute of Diabetes and Digestive and Kidney Diseases. People with diabetes are up to four times as likely to develop cardiovascular disease as are people who do not have diabetes, according to the Cleveland Clinic. Women with diabetes are twice as likely to suffer a second heart attack and four times as likely to suffer heart failure as are women who do not have the disease, according to the American Diabetes Association. “The risk of developing hypertension doubles in men and quadruples in women if you have diabetes,” MaricBilkan says. (Hypertension is a major contributor to heart disease.) “There is something about diabetes that takes away the protective factor” against heart disease that premenopausal women seem to have, something probably related to oestrogen, she says. In 2011, Maric-Bilkan test- ed a small group of premenopausal Finnish women with Type 1 diabetes and found that they all had lower-than- “Women with diabetes are twice as likely to suffer a second heart attack and four times as likely to suffer heart failure.” normal oestrogen levels. “I don’t know if they got diabetes because their estrogen levels were reduced, or the reverse,” she says, adding: “One thought is that it’s the oestrogen that gives protection, but men with diabetes, who also have a greater risk of heart disease, have high estrogen and low testosterone, the opposite of women. So the high oestrogen doesn’t protect men. Diabetic women have more testosterone than non-diabetic women, so it may have to do with the balance of hormones.” She stresses that the risk of death from heart disease “is exceptionally high in women with early-onset (Type 1) diabetes compared with women in the general population,” according to a study she authored. WHO u≥ges Af≥ica to focus on p≥eventing cance≥ By EVELYN LIRRI Special Correspondent COUNTRIES WITH limited access to cancer diagnosis and treatment services, especially in Africa, should focus on prevention programmes in order to address the burden of the disease on the continent, the World Health Organisation has said. Less than 30 per cent of developing coun- tries have accessible diagnosis and treatment services while the referral systems for suspected cancer cases are often unavailable. “Diagnosing cancer in late stages and the in- A radiotherapy machine at the Aga Khan University Hospital in Nairobi. Picture: File ability to provide treatment condemns many people to unnecessary and early death,” said Dr Etienne Krug, director of WHO’s Department for the Management of Non-Communicable diseases. WHO says a comprehensive cancer control programme, which focuses on prevention, early diagnosis, screening, treatment and palliative care should be part of strong national cancer control plans for all countries, especially those with limited resources. Health experts say when cancer is diagnosed late, it becomes costly and harder to treat successfully. As a result, countries in Africa and Asia account for two-thirds of the global 8.8 million cancer deaths that occur annually. Globally, more than 14 million people de- velop cancer every year, and WHO projects this figure could grow to over 21 million by 2030 if comprehensive prevention programmes are not put in place. Common risk factors for cancer include physical inactivity, obesity, heavy smoking and drinking. But Dr Ruth Aceng, Uganda’s Minister of Health said most cancers in the East African region are caused by viruses. This also makes them the easier types of cancers to prevent with interventions such as vaccines. Common cancers in the region include can- cers of the breast, cervix, prostate, liver and Kaposi’s sarcoma. “Most cancers in Uganda get diagnosed at stage three and four of the disease, which reduces the patients’ chances of survival,” said Dr Aceng. Dr Jackson Orem, the director of the Uganda Cancer Institute, noted that late diagnosis of the disease is the reason Uganda has one of the lowest cancer survival rates in the world — at just 20 per cent.
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