What Is Huntington’s Disease?

Huntington’s disease is an inherited (autosomal dominant) neurodegenerative disorder in which a mutation in the HTT gene (located on chromosome 4) causes abnormal repetition of the CAG trinucleotide sequence that results in the production of defective Huntington protein. Slowly, this faulty protein damages the brain cells, particularly in the region controlling body movement, cognition, and emotion regulation.

Types of Huntington’s Disease

Adult age: Arises in mid-adulthood (between 30 and 50 years of age)

Early age: also known as Juvenile Huntington’s disease, usually rare and affects children and teenagers.

Note: This disease is autosomal dominant, which means a person has a 50% chance of inheriting this mutation if one parent carries it.

Key facts about Huntington’s Disease

• Inherited disease: caused by CAG repeats in the HTT gene.
• Inheritance pattern: Autosomal dominant means there is a 50% chance of this genetic condition being inherited.
• Affected areas: Basal ganglia and cerebral cortex (affecting voluntary movement and control)
• Global prevalence: About 3–7 per 100,000 people, mostly of European ancestry
• Progression: Worsens gradually over 10–25 years (requires early diagnosis)

What are the symptoms of Huntington’s disease?

This disease mainly affects your neuronal coordination and balance, which in turn affects overall brain and emotional health.

 Motor Symptoms

• Chorea: the most common symptoms include involuntary jerking or twitching movements 
• Dystonia: muscle contractions causing abnormal postures and twisting movements.
• Impaired movements: Difficulty with walking, balance, and coordination, which may cause falls.
• Dysarthria and dysphagia: Abnormal speech and swallowing due to improper coordination of the mouth and throat muscles.

2. Cognitive Symptoms

• Affecting daily activities: Difficulty organizing or prioritizing tasks makes you less efficient while working. 
• Memory issues: Memory loss, especially when recalling information
• Decreased concentration: This creates trouble while focusing and maintaining attention.
• Slower thinking process: Creates problems while understanding tasks, and things take longer to analyze the problems and their solutions.
• Affecting decision-making—This can be due to the loss of judgment ability, which affects skills, making things harder for you to analyze.

3. Psychiatric & Behavioral Symptoms

• Depression and anxiety: This can appear a year before the actual symptoms arise, and requires testing and counselling
• Apathy: This can be due to a lack of motivation and a lack of interest in activities.
• Irritability or having aggression: related to mood swings and anger.
• Obsessive-compulsive disorders: Repetitive thoughts and actions require careful diagnosis and counseling with your psychiatrist.

Note: If anyone around you has the above symptoms, it’s important to consult your genetic counselor or neurologist for a better diagnosis following an effective treatment. The above information is solely for educational purposes and should not be used as a substitute for professional medical advice. 

How does Huntington’s disease progress?

The disease progresses slowly with time, affecting the body.

What Causes Huntington’s Disease?

While an inherited condition, the mutation in the HTT gene makes a protein called huntingtin that helps your neuronal cells work properly. The mutation is mainly due to an error in the DNA copy, resulting in the production of a defective protein. The damage to brain cells is primarily caused by this mutant protein’s toxic gain-of-function (acquiring a new, harmful property) that affects brain cells of the basal ganglia and the brain cortex that regulates your body movement, decision-making, and thinking ability.

How is Huntington’s disease diagnosed?

Your neurologist will physically examine you, looking for symptoms that affect your movement, reflexes, and coordination. After that, you may be referred to a genetic counselor, who will ask about your family history of Huntington’s disease. For behavior assessment, your psychiatrist will check for behavioral differences, based on which necessary steps will be taken.

Some of the tests include:

Neuroimaging

Imaging tests, such as MRIs or CT scans, reveal atrophy of the caudate nucleus and putamen, which are hallmarks of neuronal loss. Alternatively, functional MRI can detect early brain changes before motor symptoms appear.

Genetic Testing

A simple blood test detects HTT gene repeats. At least 40 repeats are required to confirm the diagnosis. Before testing, genetic counseling is required, especially for asymptomatic individuals.

What are the treatment for Huntington’s Disease

While there is no permanent cure, managing symptoms along with supportive care can significantly improve the quality of life.

 Pharmacological Treatment

Chorea, for example, can be controlled by reducing dopamine levels in the brain, and antipsychotics can help control involuntary movements and aggression.

 For Psychiatric Symptoms

Antidepressants can help control depression and anxiety, or mood stabilizers can be used to manage mood swings, along with antipsychotics, which are for psychosis or severe behavioral symptoms.

 Non-Pharmacological Therapies

• Physiotherapy: Enhances balance and mobility.
• Speech therapy: Helps with communication and swallowing.
• Occupational therapy: Adapts daily activities to promote independence.
• Psychological counseling: Helps both patients and caregivers.

Nutrition Support

Because swallowing becomes difficult, a high-calorie, soft diet is recommended. Nutritional supplements may help prevent weight loss.

Huntington’s Disease: Emerging Research and Future Therapies

In the field of gene therapy, many research studies have been done  for Huntington’s disease to develop precision medicine

1. Gene Silencing Approaches

Researchers are using antisense oligonucleotides (ASOs) to “silence” the mutant HTT gene.

Tominersen (by Roche/Ionis) is one such drug under investigation with a goal to reduce toxic huntingtin protein levels and slow disease progression.

2. RNA Interference (RNAi)

This uses small interfering RNAs (siRNAs) to block mutant gene expression—a promising method for selective gene targeting.

3. CRISPR-Cas9 Gene Editing

Advanced gene editing techniques like CRISPR could eliminate expanded CAG repeats, potentially correcting the mutation at its source—a step toward curative therapy.

4. Neuroprotective & Cell-Based Therapies

• It is a Stem cell transplantation that promises to replace damaged neurons.
• BDNF (Brain-Derived Neurotrophic Factor) therapies aim to protect neurons from degeneration.
• Mitochondrial-targeted drugs may restore cellular energy balance.

5. Digital Biomarkers

Wearables and smartphone-based cognitive tests are being used to monitor early symptoms, assisting researchers in customizing interventions.

Conclusion

Huntington’s disease is a life-threatening condition but a widely studied neurodegenerative disorder. While there is no permanent cure currently available, advances in genetics, neuroscience, and biotechnology are clearing the way for treatments that could slow or prevent the disease from developing at all. Early detection, personalized gene therapy, and coordinated support are the keys to the future of Huntington’s disease care, providing families around the world with new hope along with improved quality of life.

FAQs

What is the Life expectancy of Huntington’s Disease?

The life expectancy in Huntington’s disease (HD) varies greatly from person to person. On average, adults diagnosed with HD live about 15 to 20 years after the onset of symptoms. However, the total time from the first signs of the disease to death can vary between 10 and 30 years, depending on how quickly the condition progresses. Those with the juvenile form of Huntington’s disease, which progresses more quickly, typically live for 10 to 15 years after symptoms appear.

Is Huntington’s Disease painful?

Yes, this disease can cause pain, with studies showing that around ~41% of people experience pain during later stages, and this pain mainly occurs due to the psychological factors like anxiety and depression, which can further exacerbate the pain. Consult with your doctor for pain management for an efficient recovery.

What is Juvenile Huntington’s Disease?

 Juvenile Huntington’s disease appears in ~5–10% of people under 20 years old. It’s usually linked with larger CAG expansions (>60 repeats) and progresses more rapidly.

Common Features

• Stiffness and rigidity (rather than chorea)
• Seizures
• Drop in academic performance
• Change in Behaviour

What is the ICD-10 code for Huntington’s disease?

G10 is the code for Huntington’s disease, “Diseases of the nervous system,” used for all forms of Huntington’s disease, including adult-onset and juvenile types.