Dr. Crutchfield, my nephew said there may be a new treatment called CRISPR for hundreds of diseases. What in the world is CRISPR?
CRISPR is science and medicine’s potential secret weapon for treating and preventing inherited diseases like sickle cell anemia, among many others. Asked to comment about the potential of CRISPR, scientists and doctors who understand it may respond by saying:
- CRISPR is THE next “big thing.”
- CRISPR has the potential to absolutely revolutionize medicine.
- CRISPR is the most important scientific discovery of the last 100 years.
- CRISPR has the potential to change the world as we know it.
These are incredible statements, but they may just turn out to be true.
CRISPR is a system that allows one to edit the DNA of living organisms, including humans. Pronounced “crisper,” the acronym sounds like a drawer in a refrigerator, but it actually stands for “Clustered Regularly Interspaced Short Palindromic Repeats.”
Our DNA is a series of instructions – how tall we are, what color eyes we have, and any number of thousands of traits – that add up to making us who we are. The instructions are written as a series of chemical letters in our DNA located in the nucleus of every cell. These genetic instructions are the same for all living organisms, from worms to corn plants.
Just like a book filled with letters that make up words and sentences that constitute paragraphs and allow the reader to understand the story, sometimes, rarely, there can be an error or misprint in the letters of our DNA. We pass on our DNA to our offspring, so if there is an error, there is a chance that our children will inherit the mistake.
Sometimes, the DNA error means nothing. Other times, a DNA error of even a single letter can so profoundly affect a gene that it causes a terrible disease.
For example, sickle cell disease is just such a case. If only one single letter in the DNA instructions is incorrect and makes structural protein in our blood cells weak, these weak blood cells can clump and clog our blood vessels, leading to pain, damaged organs, and even premature death.
How does CRISPR work?
CRISPR was discovered in bacteria. Bacteria have developed an ingenious system of protection against foreign invaders, especially viruses that infect bacteria. Bacteria possess an enzyme complex called CRISPR that recognizes foreign viral DNA in subsequent infections and chops it up, rendering it ineffective. It’s like an immune system for bacteria.
Scientists can now take this enzyme complex (containing an enzyme cutter called Cas9 and an RNA guide component) and program it to recognize any DNA sequence, bind to it, and then cut it. Not only can it cut out defective DNA, but it can also be programmed to repair defective DNA with the correct DNA!
So now, if someone has a defective gene, we have the potential to repair it. Additionally, we also have the potential to correct faulty genes and DNA in eggs and sperm, so the disease will not be passed on to children. Of course, getting programmed CRISPR into a human body and the desired cells isn’t going to be easy, but scientists are working on it around the clock.
There are over 600 diseases (like cancer, sickle cell, Alzheimer’s, Huntington’s, ALS, hemophilia and many others) that are the result of defective DNA. CRISPR has the potential to prevent and/or cure them all.
CRISPR is revolutionizing medicine. It makes research more effective and precise, faster, easier, and less expensive. This is truly life-changing and world-changing science.
Think of CRISPR as a word processor and our DNA as the set of instructions, like words on a page that spell out who we are. Now, with CRISPR, scientists potentially have the power to correct any “typos,” rewrite our instructions, and permanently change who we are, much like changing the letters, words or sentences on a written page with a word processor.
The Human Genome Project was an international effort to decode all DNA in humans. This meant deciphering almost three billion DNA letters, which codes for more than 30,000 human genes. The project began in 1990 and was declared finished in 2003.
During that time, we learned what the human genes coded for, and what defects in them caused disease, but we had no way of fixing the errors that caused disease. Now, with CRISPR, we can.
The most exciting thing about CRISPR is that the discoverers are allowing it to be used by scientists around the world to work on almost any legitimate scientific project. It can be purchased online for less than $100. To date, it has been ordered over 44,000 times and shipped to over 2,100 research laboratories in over 60 different countries around the world.
Easily editing DNA is no longer science fiction. Dozens of companies have been established around the world to develop CRISPR technology. CRISPR technology will undoubtedly fuel a multi-billion-dollar therapeutic market in just the next few years.
Scientists have used it to treat mosquitoes so they can’t transmit certain diseases, rice plants to withstand severe weather conditions, and dogs to be more muscular. They have even treated blind mice and monkeys, enabling them to see.
As mentioned earlier, researchers are also using CRISPR to correct defective genes (for a type of inherited heart disease) in sperm and eggs so that, in the future, their children may not inherit the disease. This has the potential to change the genetic history of a family who has suffered from devastating genetic diseases for generations. This is just the tip of the proverbial “iceberg” for CRISPR.
Doctors say let’s use CRISPR to treat human disease and suffering. It should make a significant impact in health care over the next 10 years, and CRISPR will be transformative for the health of the next generation of humans.
While CRISPR technology has the potential to eliminate disease and suffering, it also has the potential to be abused. If we can rewrite DNA, why not rewrite DNA to produce designer babies who are smarter, more attractive, taller or stronger?
Most scientists agree we are nowhere close to changing humans. Researchers say that changing genes is incredibly complicated. For example, eliminating one gene can decrease the risk for heart disease, but at the same time it can increase the risk for diabetes. There is much to be understood.
With CRISPR we can change our DNA. When we change our DNA, we can change ourselves and all of our descendants. The profound potential of CRISPR is ineffable. The key is to use CRISPR safely and ethically.
Charles E. Crutchfield III, MD is a board-certified dermatologist and clinical professor of dermatology at the University of Minnesota Medical School and a Benedict Distinguished Visiting Professor of biology at Carleton College. He also has a private practice, Crutchfield Dermatology in Eagan, MN.
He received his MD and Master’s Degree in molecular biology and
genomics from the Mayo Clinic. He has been selected as one of the top 10 dermatologists in the United States by Black Enterprise magazine. Minnesota Medicine recognized Dr. Crutchfield as one of the 100 Most Influential Healthcare Leaders in Minnesota. Dr. Crutchfield specializes in
skin-of-color and has been selected by physicians and nurses as one of the leading dermatologists in Minnesota for the past 18 years.
He is the team dermatologist for the Minnesota Twins, Vikings, Timberwolves, Wild and Lynx. Dr. Crutchfield is an active member of both the American and National Medical Associations and president of the Minnesota Association of Black Physicians. He can be reached at CrutchfieldDermatology.com or by calling 651-209-3600.