What is the difference between a care partner and a caregiver?
The difference is that of a one- versus a two-way street.
A caregiver is someone who provides care for someone who is unable to care for themselves. The term implies a one-way relationship between two people–one gives and the other receives. It suggests that a passive role is taken by the recipient of care.
However, caring is often a two-way street, and this balance of care is more fully captured by the term, care partner. A partnership is characterized by mutual cooperation and joint responsibilities. There are opportunities to give as well as receive by both parties in a care partnership. The term is more inclusive and egalitarian.
Why does this distinction matter?
Words can be impactful. The difference in how a relationship is defined can affect how roles are viewed, as well as the sense of agency that an individual feels. “Care partner” evokes a sense of cooperation and common goals. There is a mutual sense of purpose, as each person in the partnership has a role in the care and support provided.
This is not to detract from the role and value of caregivers in society. The distinction between caregiver and care partner simply captures a different type of relationship that is common among those living with medical conditions that deserves recognition. More
Huntington’s Disease: Care Partner’s Guide
A Message from Pope Francis
Note: Thank you to Stanford’s Huntington’s Disease Support Group for directing us to this speech given by Pope Francis to Huntington’s Disease patients and their families. We were moved by his compassion and powerful words of support and wanted to pass the Pope’s message along to those in the HD community:
“Disease can also be an opportunity for encounter, for sharing, for solidarity. The sick people who encountered Jesus were restored above all by this awareness. They felt they were listened to, respected, loved. May none of you ever feel you are alone; may none of you feel you are a burden; may no one feel the need to run away. You are precious in the eyes of God; you are precious in the eyes of the Church!
I now turn to the families. Those who experience Huntington’s Disease know that no one can really overcome loneliness and despair if they do not have people at their side who, with self-sacrifice and steadfastness, make themselves ‘travel companions’. You are all this: fathers, mothers, husbands, wives, children, brothers and sisters who, on a daily basis, silently but effectively, accompany your family members on this difficult path. For you, too, at times, the path is an uphill climb. For this reason, I encourage you, too, not to feel you are alone; not to give in to the temptation of the sense of shame or guilt. The family is the privileged place of life and of dignity, and you can cooperate to build that network of solidarity and of help that the family alone can guarantee, and which the family is first called to live.”
The Pope’s full speech can be found at the following link: https://w2.vatican.va/content/francesco/en/speeches/2017/may/documents/papa-francesco_20170518_malati-corea-huntington.html
In the global spotlight, the Pope pushed back against the stigma surrounding HD and offered powerful words of support to both patients and care partners. He also praised researchers searching for treatments, but cautioned against the use of human embryos in research, encouraging scientists to work “in ways that do not contribute to nourishing the ‘throwaway culture’ that sometimes creeps into scientific research.” He argued that “no end, even a noble one like the expectation of a benefit for science, for other human beings or for society, can justify the destruction of human embryos.” While this argument remains controversial and often produces polarized viewpoints, the global gathering remained a unifying event for those affected by Huntington’s Disease.
Pope Francis’ address was given at Aula Paolo VI in Vatican City, Rome during a global gathering that made headlines as the first time a world leader spoke publicly about Huntington’s Disease. Nearly 1,700 people came to the event, 150 of whom were patients, breaking the world record for the largest gathering of those affected by Huntington’s Disease. The event was organized as part of an initiative called Hddennomore ( “Hidden no more”) that seeks to relieve patients and families of the stigma and discrimination surrounding Huntington’s Disease.
Huntington’s disease has a notably high prevalence in certain populations in Latin America, reaching 1,000 times the prevalence observed anywhere else in the world. There are clusters around Lake Maracaibo in Venezuela, and others in Peru and Brazil where the prevalence reaches 2450 per 100,000 inhabitants. These areas are afflicted by poverty, lack of education, and poor access to social services and sufficient medical care. Oftentimes, the communities do not even have access to the genetic test for HD. Moreover, families must care for members afflicted by the disease in challenging living conditions, while facing stigma and discrimination from the communities they live in. Families from over two dozen countries attended Pope Francis’ global gathering, and through support from donors, HDdennomore was able to fly in families from Venezuela, Argentina, and Colombia.
The stigma surrounding Huntington’s disease can be traced back several generations across all regions of the world. In the 1930s, the eugenics movement in the United States suggested forced sterilization of people with Huntington’s Disease. In Nazi Germany, the “Law for the Prevention of Genetically Diseased Offspring” passed compulsory sterilizations, and between 1939 and 1941, Hitler passed the Action T4 program that killed between 75,000 to 250,000 people with intellectual or physical disabilities. In more remote parts of the world with poor understanding and awareness of the disease, there is massive stigma and superstition attached to the condition.
The event at the Vatican was meaningful because it mobilized collective action to lift the stigma and shame surrounding the disease. It was a reminder to patients and families that they are not alone in their experiences and that there is a global community that stands with them, offering compassion and support for the challenges that they face.
An Interview with Roy Nierenberg
Part 3 of 3: Looking Ahead
By Linda Shin
(Click here for Part 1: Living with Huntington’s Disease)
(Click here for Part 2: Relationships and New Endeavors)
“HOPES: An Interview with Roy Nierenberg” continued…
“I’m active, but I have a feeling that being active and doing these things promote my health. The activity is part of the system and plan, and I mean, I think it’s really wonderful that I can do it—that I live in a beautiful place, bicycle most of the year, and go to Qi Gong, and be in my chorus. The other motivation came from my leukemia. I was very, very sick. I thought I might die. And yet when I got through it, it was like a second birth. And it made me feel that I should really continue.”
Roy (left) leading a weekly Qi Gong class in San Francisco. (HOPES)
Advice to patients with HD:
“For patients, understand the difficulties of someone caring for you. For example, my wife needs space. I mean I can’t have all my bubbly ideas with her and all the time because she’s needs to process it herself. And that is important to do, and she wanted me to be away 3 weeks during the summer, and I could. I visited with my mom, and that helped her somewhat. You have to, I mean, not wear them out.
And she has a Yahoo support group for care managers, which is useful. I can try to find it—try to reference it, and it’s where people can talk about it: ‘This is the problem I have. What do you think?’ And that was really helpful for her. In fact, the reason why we have separate computers is she didn’t want me kind of messing with – we used to share an e-mail account, and she says, ‘Nope! We need our own e-mail.’ But it was because she needed that privacy, and what she did is she extracted from like a big document of ‘if this happens do this; if this happens, do this.’ Because that’s the sort of problem-solver she is. Um, I mean, I really love the support group that Andrea Kwon has. It’s worth the two hours to get there. And um, I went to a support group in New York, twice. And uh, it wasn’t quite the same, but it was all right.
As a result, I asked Columbia if they could treat me as a patient. They said no, but I had an hour-long conversation with the social worker. She emailed me that I was phenomenal, and I sent this to HDSA’s main office and advocated that I should be a speaker on Living Positively with HD at the National Convention.”
The HD-COPE team in London. (Roy Nierenberg)
A personal hero and patient empowerment
“I have a hero! It’s a woman I know who has Parkinson’s disease, Sara Riggare. She’s smart and she inspires me all the time, and I met her in the States at a group called Quantified Self, where she participates. I saw a talk that she made in Amsterdam, “Quantified Self” about her pill taking, and tracking her pills, and developing a device that could measure how well she’s doing, because in Parkinson’s, they’ve got a whole bunch of drugs that they can get you, but the coordination of the drugs is still not there. But she is so fantastic; she was an engineer, then went back to bioinformatics in Sweden, and she’s figuring out patient empowerment. And she’s just a fantastic person. I have utter confidence in her, and love and affection. I think patient empowerment is really powerful, and I think it’s the future. We just have to get there.”
Goals for the future:
“Continue doing what I’m doing. Now, financially, we are not set up to hire people to physically take care of me, and my father at the end of his life, he was on Medicaid in New York. He had 24/7 people around. Mimi’s not capable of doing that or interested in doing that. So that’s not my future. So, I mean, I feel that there’ll come a time when we can’t do the same thing as we have. We may have to move, and California’s not set up for Medi-Cal covering Huntington’s. It’s just not set up that way. New York still is.
So, during a recent family reunion, I visited a Huntington’s facility in Rhinebeck, New York. And I think it was brave of me to do that but I think it’s all right for me to check it out. I’m a friendly guy and I talked to a bicycle person. I talked to a woman who was really a firecracker named Bridget, who met the Pope recently, and she said, ‘You should move here!’ She wanted to recruit me. So, I don’t know if that’ll be what I do, but you know, I’m trying to figure that out, but there are a lot of steps before then.
I don’t know if you noticed, but when you drove up the hill, there’s a big hill. I have to bicycle up this hill every day, but that’s part of it. In other words, I want to have a bicycle gear that has a very big first gear, but secondly, having the challenge is what helps me sleep and all the other parts of it.”
Roy (center) at the Palo Alto Huntington’s Disease Support Group. (Mr. Hanson-Kahn)
An Interview with Roy Nierenberg
Part 2 of 3: Relationships and New Endeavors
By Linda Shin
(Click here for Part 1: Living with Huntington’s Disease)
“HOPES: An Interview with Roy Nierenberg” continued…
Relationship with family:
“I’ve got my wife, Mimi, a daughter who is 30 years old and a son who is 26 years old. And they’re all really supportive and wonderful. Mimi is my main caregiver and it’s been hard for her. And, we’ve adjusted in a bunch of ways. One way is we’ve recently just bought new beds. We bought like two separate beds—two twin beds. Because what I was doing is like having some form of chorea, is pulling blankets off or kicking her or when I turned around in my bed, she felt it was like an earthquake. So she wasn’t sleeping and she’s doing lots and lots of stuff. So at my last neurologist appointment, he suggested, ‘Why don’t you try a different type of bed structure?’ And we’ve found it’s better, she’s sleeping better, so it’s great.
I don’t think I’d be doing so well if it wasn’t for her. She is there for me, but I can’t wear her out. And there’s so many things that she has to do, and part of it is kind of working through my business, and she’s been selling it, or closing it, I’m not sure, but I have to give her full rein to do that, and know that it’s in my best interest to do that. And we think the best thing we did is to have kids, and they’re fantastic. And I mean, Huntington’s is a scary disease and we have to make room for it in the family, but you know, we are doing it.”
Impact of HD on a changing lifestyle:
“My neurologist said, ‘Hey Roy, I don’t want you driving anymore.’ He said, ‘You’re a little impulsive, and to be impulsive with a car is not good. We couldn’t defend you. You couldn’t have hired a lawyer to defend you.’ And my snarky kind of reaction was to say, ‘I think we’re better at picking lawyers than we are at picking doctors,’ but I stopped. And I said, well, I’m going to bicycle more. And so it’s kind of an approach to things. The way I’m coping is by having a bunch of activities that stimulate my body, stimulate my mind, allow me to sleep, and that is how I am coping.”
Adopting new pursuits:
“One my friends, Mary Selk, who I know from when our kids were young said, ‘Roy, you have Huntington’s Disease. You might wanna try Qi Gong.’ So I did, and I loved it. I just loved it. And it was like–It was just beautiful. It was like yoga in motion. I just loved that practice. I loved having a bunch of friends to do an activity with, who knew me well.
Roy (left) pictured leading a weekly Qi Gong class in San Francisco. (HOPES)
We have a chorus, the Berkeley Community Chorus & Orchestra that has 220 people in it, so a lot of people, but it’s really wonderful. And the day of the week when I have choral rehearsals, Monday, and Qi Gong, it’s my best day of the week.
We’re learning a piece in Russian called Alexander Nevsky. I don’t know if you’ve ever heard of that. It was a movie, a Russian movie, made in 1938, and the subplot of the movie is in the 12th century: the Teutonic Knights from Germany, from the Holy Roman Empire are invading Russia, and Alexander Nevsky rises from the peasants to lead them, and there’s a battle on the ice. So all this is gonna be, all this is gonna be what I’m learning, experiencing in the fall. I feel so lucky for that.
The day when he brings the chorus—we hire an orchestra and soloists—the day that we have the chorus, the soloists, and the orchestra together – the orchestra is about 15 members—it can be so exciting. In fact, one of the times when we did that, that came upon me. I found that I didn’t wanna be anywhere else. And I mean, it’s a unique feeling, but a wonderful feeling. You don’t need to be anywhere else. And the performance was really neat.”
A favorite memory:
“For the 50th anniversary of my chorus, we performed a piece called Britten’s “War Requiem” which was written after World War II. It was a masterpiece. I went on a retreat with the chorus, and it was really neat. The person who was running it was the music director of the San Francisco Symphony / Chorus, and he was fantastic. I felt so good. I came back to Qi Gong the next day, and one of the people, my friend Sierra, says, ‘I don’t know what you’re doing, but keep doing it.’”
(Click here for Part 3: Looking Ahead) More
An Interview with Roy Nierenberg
Part 1 of 3: Living with Huntington’s Disease
By Linda Shin
Roy Nierenberg’s life changed dramatically when he was diagnosed with the Huntington’s Disease gene in 2009. A brilliant man, with degrees in physics, law, and economics, Roy has lived the type of influential and relevant life most of us only fantasize about. He served in the Office of the President for both President Ford and President Carter as a lawyer and an economist before moving into the private sector.
In 1983, Roy founded a company that produced computer-assisted thinking software to help users plan better projects and think up new ideas. The company thrived under his leadership for nearly 30 years. Then, his family began to notice a cognitive decline. The HD diagnosis forced him to step away from the leadership role he enjoyed for so long.
Now retired, at 72, Roy finds meaning and relevance in different pursuits. He enjoys singing in the Berkeley Community Chorus & Orchestra, riding his bike, going to science lectures, practicing Qi Gong, and going to support groups.
Roy is married and has two children. Roy’s wife (and care partner) joined an online support group for HD caregivers and founded an in-person HD support group for Caregivers in the East Bay.
Last summer, Roy accepted a request from HOPES to share his personal experiences and insights with the broader HD community. The interview is broken up into 3 parts: 1) Living with HD, 2) Relationships and New Endeavors, 3) Looking Ahead. These are his stories.
Living with Huntington’s Disease:
“I have Huntington’s Disease. It’s a genetic disease. Each child of someone with HD has a 50% chance of inheriting HD, and I found out I was vulnerable in 2 thousand and—hold on a second—2008. And it’s the second major disease I’ve had. I had leukemia, and immediately after I finished chemo and was entirely in remission, I got tested for Huntington’s. I found out I had it.
My father had what’s called chorea in Huntington’s—which is the jerky movements. But he wouldn’t tell—he would not tell me what disease he had. And he wanted—I mean, I think he was a little ashamed of it, and in denial of it.
I was visiting him more often at that point. I said ‘Pop, I know you love us. I’m sure you’d tell us if what you have is anything that can be passed on.’ He said ‘I’ll get back to you.’ And a couple of weeks later, the day I found out that I had Huntington’s Disease, he called and said, ‘The family lost money with Madoff, and I have Huntington’s Disease.’ The family had invested in Madoff and, I mean, I’m not glad the family lost money because of Madoff, but it was the thing that led him to disclose that he had Huntington’s Disease. So I started going to support groups, and I started reading about it.”
Roy (center left) at the monthly Huntington’s Disease support group meeting in Palo Alto (Mr. Hanson-Kahn)
Running a company with Huntington’s Disease:
“When I found I had Huntington’s disease, and I was running my software company, I decided to talk with someone who helped my son through learning disabilities. Chuck Ahern, PhD, a consultant. He’s really great. He said, ‘You know, I don’t normally see people who aren’t teenagers, but I can do it.’ He had me take a cognitive neuro-psych assessment. It took 8 hours. It was expensive. And the psychologist said, ‘Roy, you’re still smart, but you’re slower, and you’ve lost like 25 points on your IQ.’ But my IQ was high to start with, which was neuroprotective. Chuck said, ‘you should bring someone else in the family.’ So I brought in my 22-year-old daughter to run my software company.
We’ve closed down the company since then, and Huntington’s Disease prevented me from really being able to make good business decisions. I also couldn’t balance a checkbook. I was bouncing checks, and not making good business decisions.”
(Click here for Part 2: Relationships and New Endeavors) More
What is compassion fatigue?
“ As witnesses and healers, we cannot help taking on the emotional pain of those we are privileged to know and care for. We collect bits and pieces of their trauma by exposure to their lives.
We have pictures in our minds and intense feelings in our bodies at the end of the day. Those who are strongly empathetic may be most at risk. We feel for those who are hurt by life’s events: challenges, life threatening illness, impending death, sudden/traumatic death, and bereavement.
We do not just witness in the abstract, it is personal. We actually experience the pain vicariously. Consequently, it affects us psychologically.
Hence, we are at risk of compassion fatigue.”
– Sherry E. Showalter, PhD, LCSW, BCD
Compassion fatigue is a form of secondary traumatic stress associated with caregiving/care-partner roles. It is a combination of physical, emotional, and spiritual exhaustion resulting from repetitive, empathic responses to the suffering of others. Compassion fatigue is commonly experienced by nurses, physicians, and other healthcare professionals. However, family members taking on a care-partner role may also develop this condition.
Why does compassion fatigue matter?
Compassion fatigue matters for the millions of caregivers, care partners, family members, health care professionals, and emergency service workers who provide constant, empathetic care to those affected by illness, trauma, loss, and impending death. The symptoms of compassion fatigue have the potential to disrupt and devastate families, careers, and lives. Research has shown that the symptoms of compassion fatigue are very responsive to treatment once recognized and actively addressed. With targeted intervention, those with compassion fatigue can experience profound transformations and personal empowerment. This allows individuals to improve their care for others while finding positive balance in their own lives.
How does compassion fatigue develop?
Figure 1: Compassion Fatigue Process (Retrieved from https://openi.nlm.nih.gov/detailedresult.php?img=PMC3170786_NRP2011-408024.001&req=4)
Compassion fatigue is caused by repeated empathic connection to people who are suffering intense pain or adversity. Over a long period of exposure, care partners will closely identify with the patient/family member/person they are caring for and ultimately come to absorb the suffering of those they care for. Figley (2002) proposed a model to describe how compassion fatigue develops:
- Compassion fatigue results from a combination of:
- Compassion stress
- Extended exposure to suffering
- A sense of responsibility for the care of the individual who is suffering
- Traumatic memories
- Associated reactions, such as depression and anxiety
What are the symptoms?
- Digestive problems: diarrhea, constipation, upset stomach
- Muscle tension
- Sleep disturbances: inability to sleep, insomnia, too much sleep, nightmares
- Cardiac symptoms: chest pain/pressure, palpitations, tachycardia
- Sadness and grief
- Mood swings
- Excessive use of substances: nicotine, alcohol, illicit drugs
- Anger and resentment
- Loss of objectivity
- Memory issues
- Poor concentration, focus, and judgment
- Decreased intimacy
- Avoidance or dread of working with certain patients
- Reduced ability to feel empathy towards patients or families
- Frequent use of sick days
- Lack of joyfulness
What is the difference between compassion fatigue and burnout?
Many studies refer to “family burnout” when describing interpersonal relationships such as family caregiving. However, there is an important distinction between compassion fatigue and burnout. Burnout is physical or mental exhaustion caused by stress, a more general term that does not include the elements of empathy that define compassion fatigue. While burnout is cumulative and tends to follow a predictable course, compassion fatigue can be more complex, as it results from intense, extended empathic care for people experiencing pain or suffering. Burnout can be experienced in all professions, whereas only individuals in caregiving/care-partner positions experience compassion fatigue.
What research has been conducted on compassion fatigue experienced by family caregivers?
The majority of literature on compassion fatigue is centered around nurses, physicians, and healthcare professionals. However, more research is emerging on family caregivers who experience this condition. Perry, Dalton, and Edwards (2010) from Athabasca University published a study suggesting that compassion fatigue among family care partners may parallel the conditions experienced by professional caregivers. Their study focused on five family caregivers in long term care in Canada. The researchers discovered that caregivers were unable to disengage from their caregiver role to find balance and rest when needed, no matter how difficult it was or how high the cost.
They found two themes that emerged among the family care partners: role engulfment and enveloping sadness.
For many family members, the care partner role appeared to engulf their lives. One participant stated: “I think maybe I am here too much. I have no other parts to my life.”
Some participants worried about their family member/loved one almost continually. Caregiving had an overwhelming effect on the social aspect of their lives. Some struggled to maintain other relationships while fulfilling caregiving responsibilities. One participant spoke about the conflicts between assisting with care and social relationships: “Now I do what I can for her but I feel torn between my other responsibilities and her. I don’t feel like I am doing a great job of anything. I don’t feel like I have a social life at all.”
The physical health of the family care partners was also affected. Many neglected self-care, and participants noted a decline in their own physical health as a result of the intensity of their care partner role.
The study revealed that participants were seemed engulfed by their commitment and responsibility to ensure quality care for their loved ones.
Participants of the study also expressed a sense of loss, and some described the loss in terms of losing their relative as the person they once were. One participant, whose mother had progressive dementia, described: “I have lost my mom, who was more than a mom to me – she was a really good friend. Now she doesn’t even know who I am.” Another participant cried as she spoke: “I really wish I could have my old husband back. Even though we had our spats it was still better than this.”
Sadness close to despair accompanied these expressions of loss. Several participants reported feeling sad and crying in response to their care partner experiences. Several expressed sadness caused by perceptions that their relative may be suffering due to unmet care needs.
When participants of the study lost hope for a better future for their relative or themselves, their sadness was magnified. One participant noted: “It is the same everyday – nothing changes in my life. I see what I have to look forward to for the next years and I don’t see much hope of anything good happening.”
Researchers of this study described how this sense of loss and hopelessness appeared to have created an enveloping sadness and a heavy heart in family members.
How is compassion fatigue treated?
Compassion fatigue can be prevented or effectively addressed in family caregivers. The first step for intervention is to seek available resources, which in some cases includes professional therapy. Developing positive self-care strategies and healthy rituals is crucial for a care partner’s well being. Healthy rituals are activities performed on a regular basis that replenish personal energy levels and enhance feelings of well being.As caregivers tend to the needs of others, they often neglect their own needs such as adequate rest, nutrition, hydration, sleep, and exercise. Overcoming compassion fatigue requires genuine self-reflection and attention to the issue.
What are some resources available to family caregivers?
National Family Caregiving Association (NFCA) – A non-profit organization providing education, peer support, and resources to family caregivers across the country free of charge.
10400 Connecticut Avenue Suite 500
Kensington, MD 20985
National Alliance for Caregiving – A non-profit coalition of national organizations focused on improving the lives of family caregivers
4720 Montgomery Lane, Suite 205
Bethesda, MD 20814
Rosalynn Carter Institute for Caregiving – An institute focused on helping caregivers coping with chronic illness and disability across the lifespan
Georgia Southwestern State University
800 GSW State University Dr.
Americus, Georgia 31709
Further Reading on Compassion Fatigue:
Day JR, Anderson RA, Davis LL. Compassion Fatigue in Adult Daughter Caregivers of a Parent with Dementia. Issues in mental health nursing. 2014;35(10):796-804. doi:10.3109/01612840.2014.917133. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4683933/
Figley, C.R. (2002). Compassion fatigue as secondary traumatic stress disorder: An overview. In C.R. Figley (Ed.). Compassion fatigue: Coping with secondary traumatic stress disorder in those who treat the traumatized (pp. 1-20). New York, NY: Brunner-Mazel.
Perry, B., Dalton, J.E., & Edwards, M. (2010). Family caregivers’ compassion fatigue in long-term facilities. Nursing Older People, 22(4), 26-31.
Showalter SE. Compassion Fatigue: What Is It? Why Does It Matter? Recognizing the Symptoms, Acknowledging the Impact, Developing the Tools to Prevent Compassion Fatigue, and Strengthen the Professional Already Suffering From the Effects. American Journal of Hospice and Palliative Medicine. 2010;27(4):239-242. doi:10.1177/1049909109354096. More
What is CRISPR-Cas9?
CRISPR-Cas9 is a new technology used to edit the genome (complete set of DNA) in any living organism—including humans.
Haven’t researchers been editing genomes already?
Yes, since the mid-1970s, scientists have been changing the DNA of living organisms. Researchers have traditionally used model organisms such as mice and fruit flies, as they are among the few species that come with an effective toolkit for genetic manipulation (i.e. shorter life cycles and large numbers of offspring). Using these techniques, however, it can take over a year to create new lines of genetically altered mice, as the editing of embryonic stem cells is inefficient.
Unlike alternative gene-editing techniques, CRISPR-Cas9 is cheap, quick, and easy to use. It outperforms older methods for gene editing, as it is easier to employ, has a high success rate, and is far more user-friendly to the average scientist.
In fact, Dr. Josiah Zayner, a former NASA researcher, created an Indiegogo campaign to sell do-it-yourself CRISPR kits, encouraging amateur scientists to try gene editing for themselves and claiming that his NASA lab could be replicated “on a kitchen table.”
CRISPR-Cas9 is allowing for research that would otherwise have required too much time or money to carry out. This technology is also not limited to a set of model organisms. Theoretically, it is possible to edit the genes of any living organism.
Where did CRISPR come from and how does it work?
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) are DNA sequences that are found in naturally-occurring bacterial immune system.
Bacteria can often be infected by viruses and the CRISPR immune system can be used to protect against these attacks through three main steps:
- Adaptation – DNA fragments of the invading virus are incorporated into the CRISPR region of the bacteria’s genome
- Synthesis of CRISPR RNA – The CRISPR sequence is transcribed to create small RNAs, each like a barcode specific to different viruses that the bacteria has seen before.
- Targeting – A Cas nuclease (CRISPR-associated protein) can then bind these barcodes that function like a genetic GPS, guiding the nuclease to destroy the DNA of the invading viruses
Image source: The Doudna Lab http://rna.berkeley.edu/crispr.html
In short, Cas proteins snip sequences of DNA, and CRISPR is a DNA sequence that tells Cas9 exactly where to snip. For more information on the mechanisms behind CRISPR-Cas9, click here.
How do researchers use CRISPR to edit specific genomes?
Before injecting the CRISPR system into a cell, researchers pre-program the guide RNA to match a designated target gene in a cell’s DNA. Once the guide RNA and Cas9 are injected into the cell, the two stay together, and the RNA directs Cas9 to a specific part of the DNA. (Note: Cas9 is one of many Cas proteins. It is the one that most researchers use as a tool in the lab, but many exist in different bacteria strains). Cas9 then snips out the targeted DNA sequence. Naturally, the cell immediately attempts to make repairs. Scientists can then rewrite the genetic code by adding an additional piece of DNA that the cell can use to repair the break. A faulty gene can then be repaired using the CRISPR-Cas 9 technology by providing a normal copy of the gene that the cell can use to repair.
Image from: http://scienceblog.cancerresearchuk.org/2016/02/01/crispr-gene-editing-new-chapter-in-cancer-research-or-blot-in-the-ethical-copybook/
How long does this process take?
Only a few days are required for a designed RNA guide sequence to arrive by mail. It takes a few months to complete the entire gene editing process using CRISPR-Cas9.
What are potential applications of this technology?
Interestingly, the dairy industry has actually been using CRISPR for several years, far before the gene editing revolution. Cheese and yoghurt manufacturers used CRISPR to create cultures better able to survive bacteriophage attacks, thereby avoiding food waste. However, this new capacity to manipulate genes quickly and precisely can be applied to develop new materials, biofuels, drugs and foods at low cost in little time. CRISPR-Cas9 technology is also anticipated to revolutionize military medical science and advance knowledge on therapy for infectious diseases, wound healing, and tissue regeneration.
Could CRISPR accelerate gene-therapy?
Theoretically, CRISPR could be applied to treat any disease caused by genetic mutations. Though we now have the capacity to edit the genome, some diseases like Huntington’s disease, primarily affect the brain, which is difficult to access. Even if the tools are available, we
In cultured human cells and in mice, this technology has been applied to target Huntington’s disease, cystic fibrosis, sickle cell anemia, among many others. However, a significant amount of work must be done before moving CRISPR into the clinical setting.
Over the last two years, several companies have been formed to develop CRISPR-based gene therapy. Editas Medicine recently announced its plans to begin clinical trials using CRISPR in 2017. Two other companies – CRISPR Therapeutics and Intellia Therapeutics—are following closely behind. Researchers hope that the technique will one day be used to tackle a wide range of genetic diseases.
What are the safety concerns?
The CRISPR technology is currently imperfect, as it occasionally results in DNA cuts and changes that weren’t intended. Many scientists warn of several barriers that need to be overcome before CRISPR can be used safely and efficiently in a clinical setting. Researchers are still working on improving the efficiency of the editing process (i.e. increasing the rates of editing) and ensuring that undesirable alterations to other parts of the genome are not made. Even rare occurrences of Cas9’s off-target snips can be very problematic. For example, incorrect manipulations can accelerate a cell’s growth and lead to cancer.
Why is this technology so controversial?
Researchers, including Jennifer Doudna of UC Berkeley, who co-invented the CRISPR technology, are concerned about attempts to make genetic modifications to viable human embryos. In other words, it is theoretically possible to modify genetic material that codes hereditary characteristics, potentially giving people the power to control specific traits passed down to children.
This issue raises many safety and ethical considerations. First, an attempt to correct one gene could result in an error that leads to an unanticipated change in another. Depending on where this error takes place, the mistake could be passed down to the child’s offspring and multiple generations may face the consequences. Second, parents who manipulate their child’s genome may be making decisions that the child may not have wanted. The Center for Genetics and Society recently released a briefing of seven key dangers of genetically modified humans.
As of today, many unanswered questions remain. While this powerful new technology is undoubtedly revolutionary and holds enormous potential for the future, researchers emphasize the need to keep expectations under control.
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