Gene-editing has started in humans: do we need to watch out!
WHATS IN THIS BLOG:
• Victoria Gray, 34, from Mississippi has sickle cell disease.
• A genetic defect deforms the red blood cells, causing terrible bouts of pain.
• A new gene-editing treatment involves a grueling round of chemotherapy, weeks in the hospital, months of tests.
• But there’s hope…
THERE WAS AN UPROAR OVER GENE-EDITING EXPERIMENTS carried out in November 2018 by Chinese biophysicist He Jiankui. He claimed to have done experiments on human embryos that resulted in twin girls whose DNA had been engineered to make them less susceptible to contracting HIV. The controversial experiments drew condemnation in China and internationally and led to the scientist’s firing from his University in January.
The problem: it’s possible that the twins inadvertently increased their susceptibility to other infectious diseases. But there’s also a danger that the experiments made unintended modifications in their genomes, as often happens in gene-editing experiments in the laboratory, leaving the twins vulnerable to genetic diseases.
CRISPR IS THE NAME OF THE MOST POPULAR GENE-EDITING TECHNIQUE. It is a method by which the genomes of living organisms may be edited (altered). Genome editing is a type of genetic engineering in which DNA is inserted, deleted, modified or replaced in the genome of a living organism. The genome of an organism is the whole of its hereditary information encoded in its DNA. The term was coined in 1920.
In 2012, Doudna and Emmanuelle Charpentier were the first to propose that CRISPR/Cas9 (enzymes from bacteria that control microbial immunity) could be used for programmable editing of genomes, which is now considered one of the most significant discoveries in the history of biology.
VICTORIA GRAY, 34, OF FOREST, MISSISSIPPI, HAS SICKLE CELL DISEASE. She is the first patient ever to be publicly identified as being involved in a study testing the use of CRISPR for a genetic disease.
The following is an adaptation of the first interview, by NPR (National Public Radio) on 29 July 2019, with someone who has volunteered for one of the most highly anticipated medical experiments in decades. It’s the first attempt to use the gene-editing technique CRISPR to treat a genetic disorder in the United States.
ROB STEIN of NPR: I went to the Sarah Cannon Research Institute in Nashville to meet Victoria Gray. Victoria is just turning 34. She lives in Forest, Mississippi, with her husband and four children. Victoria’s been struggling with sickle cell disease all her life.
VICTORIA GRAY: It’s horrible. When you can’t walk or, you know, lift up a spoon and feed yourself, it gets real hard.
ROB STEIN: Sickle cell affects millions of people around the world, including about 100,000 in the United States. Most, like Victoria, are African American. A genetic defect deforms the red blood cells, making them sickle-shaped, hard and sticky, and they don’t carry oxygen like they’re supposed to, causing terrible bouts of pain.
VICTORIA GRAY: Sometimes it feels like lightning strikes in my chest, and real sharp pains all over. And it’s the deep pain. You know? I can’t touch it and make it better or do anything to make it better. Sometimes I will be just balled up and crying, not able to do anything for myself.
ROB STEIN: The sickle cells have already damaged Victoria’s heart, made her weak, prone to infections, strokes and more. Many people with sickle cell can’t work or finish school. Many don’t make it past their forties.
ROB STEIN: But then Victoria heard about something new. Scientists were planning to use the gene-editing technique called CRISPR to try to treat sickle cell for the first time. She jumped at the chance to volunteer. Dr. Haydar Frangoul is running the study at the Nashville hospital.
ROB STEIN: CRISPR lets scientists make very precise changes in DNA. Doctors have started using CRISPR to try to treat cancer, mostly in China. Frangoul’s sickle cell study is part of a new wave of studies trying to use CRISPR to treat other diseases around the world.
ROB STEIN: So Dr Frangoul will be using cells that scientists have edited using CRISPR to flip a hemoglobin switch to turn the production of healthy hemoglobin back on.
DR FRANGOUL: And this opens the door for many patients to potentially be treated and have their disease modified to become a milder case or remove the long-term horrible, horrible side effects of sickle cell disease. However, this is a brand-new technology. It seems to work really well in animals. It’s completely unknown how it works in actual human beings. So there’s a lot of unknowns. It might make you sicker.
ROB STEIN: Dr. Frangoul acknowledges there are risks with experimental treatments. But he says the research will go very slowly and carefully with a lot of oversight by the Food and Drug Administration and others.
ROB STEIN: For her part, Victoria says she understands that there may be risks. The treatment’s not easy. It involves a grueling round of chemotherapy, weeks in the hospital, months of tests. And the study’s just the first step that may only benefit other patients years from now. But she can’t help but hope.
ROB STEIN: It’ll probably be months before the first clues emerge about whether CRISPR-edited cells are safe and might be working to remove sickle cell disease. And it may be years before anyone really knows how well the gene-editing might help patients like Victoria Gray.
VICTORIA GRAY: This gives me hope, if it gives me nothing else.
A potentially successful example of the application of genome editing techniques in crop improvement can be found in bananas, where scientists used CRISPR editing to inactivate the endogenous banana streak and overcome a major challenge in banana breeding.
I also happened to read the next statement, which astonished me. Can any of my readers confirm that such things are true?
By genetically modifying organisms, we can now create glow-in-the-dark cats and fish, mice with singing voices, less flatulent cows, and carbon-capturing plants.
Last point: There do appear dangers of gene-editing in humans. There is a risk that certain social, economic, and political forces will come to bear on those deemed “unfit” in an effort to pressure them to change their genetics so that they might better conform to certain external expectations.
The ethics debate has spilled onto the pages of newspapers and magazines, often with headlines heralding the arrival of “designer babies.”
PS: I write blogs about a curious mix of three topics: Science and Energy, and Inspiration and Hope, and Health and Hiking. Something for everyone!
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