Huntington’s disease, an inherited neuromuscular disorder that usually affects people during young adulthood or middle age and worsens over time, produces symptoms that severely affect speech, movement, cognition, and mental health. Although Huntington’s disease is incurable, early diagnosis can help physicians create a treatment approach to manage symptoms and prepare for the stages of the disease as it progresses.
On this episode of Kentucky Health, host Dr. Wayne Tuckson welcomes a professor of neurology and a board member with the Huntington’s Disease Society of America to discuss the symptoms of Huntington’s Disease and preferred treatments for the disease.
Dr. Victoria Holiday, MD, is clinical director of the Deep Brain Stimulation Program and an associate professor in the Department of Neurology at the University of Louisville School of Medicine. Father Joe Graffis is a board member of the Kentucky chapter of the Huntington’s Disease Society of America.
Holiday says that Huntington’s disease is a genetically inherited disease passed down generations of families. “It’s a movement disorder, causing abnormal movement, trouble talking, trouble swallowing, that sort of thing,” she explains. “It’s a psychiatric disorder, associated with very severe depression and other psychiatric symptoms. And then it’s a cognitive disorder – it causes memory and thinking dysfunction that can also be very disabling.”
Symptoms of Huntington’s Disease, and the Importance of Social Support
Holiday says that Huntington’s disease shares some symptoms with other neurological disorders such as Alzheimer’s disease and Amyotrophic Lateral Syndrome (ALS), but it stands alone in terms of how it is caused and in the broad range of effects it has on a person. A patient may initially present with just one symptom – depression, for example – and it may take some time before doctors are able to make an accurate diagnosis. But if a family history of Huntington’s disease can be ascertained early, that will make diagnosis easier, Holiday says.
Graffis says that growing up in Louisville, he first became aware of Huntington’s disease when the mother of one of his childhood friends came down with the disease. This occurred when both Graffis and his friend were in their teenage years. Decades later, his friend also developed Huntington’s disease, and then the friend’s younger sister did so as well. Later, his friend’s daughter was diagnosed with Huntington’s disease, and died at age 46.
“I’ve seen one family and the connected families for a long time, and it’s a devastating disease,” he says. “It’s a long, long goodbye.”
Huntington’s disease is an autosomal dominant genetic disease, meaning that a person needs to have only one copy of the mutated gene passed down from one of their two parents to get the disease. Holiday says that the vast majority of patients with Huntington’s have one normal gene and one abnormal gene. “As long as you have that one abnormal gene, it’s 100 percent that if you live long enough, you will manifest Huntington’s disease, and then you have a 50-50 chance of passing that on to your child,” she explains.
Physical changes in movement are an easily identified symptom of Huntington’s disease. Holiday says, “The most common abnormal movement that we’ll see is something called chorea, which is a dance-like kind of excessive movement.” She adds that often, people with Huntington’s disease will incorporate abnormal movements into normal ones, like brushing back their hair.
In addition to chorea, Holiday says patients with Huntington’s disease may experience slurred speech and difficulty swallowing. Some patients develop symptoms that resemble those of Parkinson’s disease, as their motion decreases and they appear stiff. On the cognitive side, Huntington’s patients can develop what is called dysexecutive syndrome. They become unable to organize time and tasks efficiently, and may be unaware of the severity of their symptoms.
Depression is common among persons with Huntington’s disease, Holiday explains. It’s not just a reaction to finding out they have the disease, but actually part of the disease.
“The psychiatric symptoms can be one of the major causes of death in individuals with Huntington’s disease because a large portion of people with Huntington’s disease die from suicide,” she says. “Which is something we have to be very aware of and caring for individuals when delivering this diagnosis.”
As someone who has witnessed several members of one family develop and die from Huntington’s disease, Graffis says that emotional responses varied for each individual. He recalls that his childhood friend was in denial early on but eventually accepted that he had the incurable disease. In the later stages, his friend would show signs of optimism about life in general when Graffis would visit him in the nursing home. On the other hand, Graffis has also been present with persons who were irritable and angry and also very confused, which are all symptoms of Huntington’s.
“It is extremely hard on families,” Graffis says, “and yet they’re all positive about trying to move forward.”
In the later stages, many persons with Huntington’s disease require constant care, and they usually receive it in a facility away from home. Graffis says that in his experience, families try to provide care as long as they can for the affected member, but that eventually the responsibilities become too great. “Some facilities are better than others, and one of the things we try to do as a board, our social worker has done a great job of helping different nursing homes deal with patients,” he says.
Genetic Testing and Treatment Options
Huntington’s disease is a rare condition, affecting roughly 30,000 people around the world at any given time, Holiday says. Her clinic at the University of Louisville is a recognized center of excellence and draws in patients from the entire state. There, they receive comprehensive care from neurologists, psychiatrists, and social workers.
If a person comes to her clinic with symptoms that suggest Huntington’s disease, Holiday will refer them for genetic testing. “It’s very important to see a specialized geneticist who has experience with Huntington’s disease, because the point of genetic counseling is to understand the downstream effect of the decision you’re about to make,” she says. “What does it mean for my family? What does it mean for my career? For my life? For every subsequent generation?”
If a person is diagnosed with Huntington’s disease and does not have children, he or she can stop the disease from being passed down through the family tree by remaining childless. Unfortunately, Holiday says, Huntington’s usually begins to have its effects during middle age, when many people have already had children.
“And so that’s where that pre-symptomatic genetic testing can really come in,” she observes. “If you’ve really got your heart set on biological children but you’ve got this strong family history of Huntington’s disease, knowing if you’re affected is really important if one of your values is to try to avoid passing it on.”
Through his role as a priest and as a board member with the Kentucky chapter of the Huntington’s Disease Society of America, Graffis often offers counseling and support to persons with the disease. He acknowledges that his own Catholic faith advocates for adherents to be "open to life."
“But individual people have to make a conscious decision about that particular choice, and you have to weigh the options,” he adds. “God willing, maybe at some point we’ll have a cure. Obviously, there is none at this time. Or maybe something that will lessen the symptoms. We’ve come a long way in 20 years.”
Holiday says that currently, treatment available for Huntington’s disease patients is limited to suppressing chorea and mood disorders with medication. But in recent years, researchers have found ways to use genetic therapy to treat neurological conditions similar to Huntington’s, she notes. Her hope, shared by others in the medical community, is that a genetic-based treatment modality will be found that at the very least will suppress the symptoms of Huntington’s and allow people who carry the gene live normal lives.
She explains that the Huntington’s gene is abnormal within a person’s DNA because a section of it is too big. “There’s something called the triplicate repeat, so in the letters that make up our genetics, the repeat length gets too long, and that produces a product that’s not usable, and now there’s potential for genetic therapy that will essentially ‘hide’ that part that is too long so that we can produce the normal gene product,” she says.
Genetic therapy addressing this triplicate repeat defect is currently being used to treat other disorders, according to Holiday. She believes that eventually researchers will find a way to apply the same principles to this incurable disease. “Anybody who’s affected (by Huntington’s) would be able to be given something like this,” she says.
