How The Huntington's Disease Gene Affects How It's Inherited

Genetics can play an important factor in many diseases. In the case of Huntington’s Disease (HD), whether your parents have already developed the illness can directly determine if you will, too. However, those who don’t have a parent with HD may still develop it. HD is typically caused by a mutation in the HTT gene, which can impact the production of an essential protein called huntingtin. Its symptoms can impact cognition, movement, and mental health. If you’ve received an HD diagnosis or are a caregiver for someone with Huntington’s Disease, online or in-person therapy can be an important form of support.

What is Huntington's disease?

Huntington’s Disease, also known as HD, is a rare disease that typically causes nerve cells to decay over time, often leading to a decrease in all brain functions. It tends to be genetic, and it usually develops in a person's 30s or 40s, but it may develop even earlier than that. Because HD normally causes your nerve cells to break down, a decline in physical and cognitive abilities typically follows suit and may lead to other health conditions.

The gene that causes Huntington's disease

A mutation in the HTT gene normally causes HD. This gene is generally responsible for telling your brain to create huntingtin, an essential protein. Huntingtin's exact purpose is not fully understood, but it's typically found in the brain, as well as in body tissue. What we do know about huntingtin is that it probably plays a key role in nerve cell health. It may keep nerve cells strong and prevent them from self-destructing.

Because most cases of HD happen in a person’s 30s and 40s, most people who want to have kids have already had them before the symptoms of the disease begin to take effect.

Inheritance rate of HD

HD can occur in about 1% to 3% of people with no family history of the disease, so the odds of both parents having the disease aren't too common. However, if they do have the gene, the odds of you developing HD tend to go up. In some cases, all children of a couple affected by HD may develop it as well.

If your parents have HD, but you don't, there can still be a risk of passing it down to your own children. It may be worth speaking to a doctor about your risks and how to make the best decision for your family if you’re considering having children.

Preimplantation options

Some parents who want children with their genetic makeup (rather than adopting, for instance) can take certain measures to make sure none of their children have HD through preimplantation genetic diagnosis. This is generally when a lab uses the parents' sperm and eggs to create multiple embryos, and the embryos are tested for any signs of the HTT mutation. If one of the embryos does not have the mutation, it can be implanted into the uterus.

This method is usually neither cheap nor without controversy, but it can be worth considering if you’re planning a family. 

Symptoms of Huntington's disease

As HD typically involves the gradual breakdown of your nerve cells, the symptoms tend to be cognitive or affect your movement. Mental health disorders may develop due to HD as well.

When HD affects your movement, it may cause subtle changes at first, but eventually, it will likely affect you enough to limit many areas of mobility. It isn't uncommon for those who are living with HD to face potentially serious injuries due to falling or losing their balance. Other symptoms can include:

• Sudden twitching or jerking movements
• Trouble swallowing; many patients with HD may need assistance swallowing their foods, as choking can be common
• Difficulty speaking due to challenges with mouth movements

Cognition generally involves processing and thinking, and cognitive skills tend to grow worse over time with HD. Related symptoms can include:

• An inability to focus
• Freezing thoughts and stumbling or repetitive speech 
• Diminished impulse control, potentially leading to behaviors like impulsive spending
• Trouble with self-awareness; feeling as if you’re “on autopilot”
• Memory problems and trouble retaining new information

HD can also lead to mental disorders, potentially including the following:

• Obsessive-compulsive disorder
• Bipolar disorder
• Depression

Prognosis

At first, people who have HD may be able to live normal lives, but over time, their symptoms will likely worsen, and they will probably need assistance to function. Life expectancy can vary from person to person. Some may live for 30 years after diagnosis, but others might pass away after just a few. 

The damage that HD causes tends to be so significant that it can drastically affect the health of the brain in a short period of time. The brain may even weigh less after years of HD as the disease begins to break down its cells.

Severe symptoms like these can change a lot about a person’s behavior and ability to live on their own. This may be especially true when symptoms begin to complicate daily life. Things like choking, falling, and seizures can accompany HD and may pose risks of their own.

Overall, between mental health and physical health concerns, the outlook for a person with HD can be complex and challenging to manage. Pursuing proper treatment may make things easier.

Treatment of Huntington's disease

Prevention through genetic counseling may be, as far as we currently know, the only way to eradicate HD. If you have HD, there may not be a cure or a way to stop it, but there may be ways to slow its progression. This usually happens by treating the symptoms.

If you exercise and eat a healthy diet, this can make your physical and mental health much better, likely helping you in the long run. Physical therapy can help with movement and reduce the number of falls and swallowing issues you may have. Mental stimulation can aid your cognitive abilities, and mental health treatment, whether through medication, psychotherapy, or both, can manage symptoms of mental illness. Always consult your doctor before starting, stopping, or changing any form of medication.

Seek help

Living with HD can be a challenge, as can living with or caring for someone with the disease. In addition to medical treatment, mental health care can ease some of the stress that often accompanies HD. 

Benefits of online therapy

Working with an online therapist may be an especially ideal option if leaving the home on a regular basis is an obstacle. Because online therapy usually allows you to receive care from the comfort of your own home, it can be one of the most convenient ways to seek help. Plus, saving money on overhead costs, gas, and other expenses related to in-person appointments can also be beneficial. 

Effectiveness of online therapy

Research generally supports the ability of online therapy to make noticeable changes in the lives of those who use it. Studies show, for instance, that online cognitive behavioral therapy (CBT) can effectively reduce symptoms of anxiety and depression, which may be experienced by those navigating challenges like living with HD. Even if mental illness isn’t a concern, having a source of support, advice, and resources for processing ups and downs can be a huge help.