Huntington’s disease – Causes, symptoms, treatments, and more

What is Huntington’s disease?

Huntington’s disease is an inherited disorder that leads to the progressive breakdown of nerve cells in the brain. It can affect a person’s functional abilities. This can lead to psychiatric and cognitive disorders and affect a person’s ability to walk, think and process a certain set of information.

People affected with the disorder can also have emotional changes, memory problems and mood swings.

Huntington’s disease can occur to anyone, and the symptoms can appear during the mid-age.

The toxic proteins tend to accumulate in the brain, which can lead to neurological symptoms. The disease can affect the other parts of the brain, which can lead to other disorders and abnormalities.

Juvenile Huntington’s disease

The symptoms of Huntington’s disease usually appear during the mid-age, but when the when onset of symptoms occurs during the early 20s, it is called juvenile Huntington’s disease.

The occurrence of juvenile Huntington’s disease is less common, and the symptoms can appear during the adolescent stage.

Causes of Huntington’s disease

Huntington’s disease is caused due to genetic mutation. When the trinucleotide is repeated in the HTT gene, it can lead to Huntington’s disease. Juvenile Huntington’s disease is usually inherited from the father. However, there are cases where the disease can be inherited from the mother.

When the elongation of the CAG repeats occurs in the short arm of the chromosome leads to Huntington’s disease. The primary role of the gene is to code for the protein called HTT, which plays a crucial role in synaptic function and the post-embryonic period.

The gene also contains an anti-apoptotic function and gives protection against mutants and toxins. People affected with Huntington’s disease will have CAG repeats in the range of 36-35 in the HTT allele.

The elongated fragments get nicked at random sites, and they attach to the neurons and disrupt the functions of the cells. This causes cell death and leads to symptoms of Huntington’s disease.

The juvenile cases will have CAG repeats that will be greater than 60. The genetic factor plays an important role in Huntington’s disease.

The other names of the disease are

• Huntington chorea
• Huntington chronic progressive hereditary chorea.

How common is Huntington’s disease?

According to NCBI, the Asian prevalence of Huntington’s disease is estimated to be 0.4 per 100,000. The overall affected population is estimated to be 5.70 per 100,000. However, the studies and affected people from India are rare.

Symptoms of Huntington’s disease

The symptoms of Huntington’s disease can represent mental and behavioural changes. It can also include changes in movement and communication. Some of the common symptoms of Huntington’s disease are listed below.

• Memory lapses
• Difficulty in concentrating
• Stumbling
• Clumsiness
• Fidgety movement of body and limbs
• Involuntary jerking
• Speaking and breathing problems
• Swallowing problems
• Difficulty in locomotion

The early symptoms of the disease include

• Memory lapses
• Depression
• Extreme mood swings
• Aggressive behaviour
• Stumbling and clumsiness

The later stages of symptoms include

• Difficulty in speaking – The initial symptoms can include difficulty in speaking, and communication can become very difficult.
• Swallowing problems – People can choke on food, and the food enters the windpipe. There are possibilities of lung infections like pneumonia due to choking on food.
• The movement can become slow and rigid.
• The ability to move around freely becomes difficult, and they eventually lose the ability to sit or stand on their own.
• Breathing problems
• Personality changes

Some of the emotional changes a person can undergo are

• Anger
• Antisocial behaviour
• Aggression
• Frustration
• Lack of emotion
• Apathy
• Depression
• Moodiness
• Cognitive changes
• Excitement
• Disorientation
• Difficulty focusing
• Reduction in orientation skills
• Problems with multitasking

In the last stage of Huntington’s disease, nursing care will be required. They will not be able to talk or walk.

Is Huntington’s disease inherited?

According to NCBI, there is a 50% chance of inheriting the disease if the children are carriers of the Huntington disease gene. Additionally, even if one of the parents passed the HTT gene with mutation to their children, there are chances of the child getting affected with the disease.

When the child inherited gene is not mutated, the children will not inherit the disease. If the child inherits the mutated gene from any one of the parents, it can affect many generations.

Diagnosis of Huntington’s disease

The preliminary diagnosis of Huntington’s disease involves a certain questionnaire, a general physical exam, a neurological and psychiatric examination and a medical history of the family.

Neurological exams involve testing muscle strength, reflexes and balance.

Psychiatric exams include mental status and mood.

Sensory examinations include vision, hearing and sense of touch.

Neuropsychological testing includes

• Reasoning
• Spatial reasoning
• Mental agility
• Language skills and
• Memory

The psychiatric evaluation that will be carried out are

• Patterns of behaviour
• Coping skills
• Evidence of substance abuse
• Emotional state
• Symptoms of disorder thinking and
• Quality of judgement.

Blood test

The healthcare professional will also ask for a blood test. The blood sample will be analysed in the laboratory to check for any genetic mutations that can cause Huntington’s disease.

Genetic test

A genetic test will be recommended by the healthcare professional during or before pregnancy.

The risk of getting affected with Huntington’s disease will be explained. It will also brief about the causes of the disease.

Imaging test

Imaging tests like CT scans and MRIs will help diagnose Huntington’s disease. These imaging tests will help to find the structure and functions of the brain.

If a person is affected by Huntington’s disease, the test will reveal the changes in brain structure and functions. These tests will also help rule out the conditions that can cause the symptoms.

Treatment of Huntington’s disease

Currently, there is no cure for the disease. However, there are medications that can treat and reduce the symptoms.

Some of the common medications that can reduce the symptoms of the disease are

Antidepressants

Antidepressants can help increase the neurotransmitters—chemicals produced in the brain.

Antipsychotic drugs

Antipsychotic drugs can help reduce the aggressive behaviour of the person.

Mood stabilising drugs

People affected with Huntington’s disease can be administered mood-stabilising drugs. These drugs can help reduce mood swings.

Prevention

Huntington’s disease cannot be prevented as they are inherited. If you are planning for pregnancy, consult your healthcare professional for the risk of your child getting affected by Huntington’s disease.

Progression of Huntington’s disease

The progression of Huntington’s disease occurs slowly, and it can worsen over time.

During the early stages, the symptoms can be controlled, and you will find it easy to do it. There might be mood swings and certain aggressive behaviour that can be controlled initially.

During the middle stages, working and driving capabilities can be affected. Swallowing food can be difficult, and unintentional weight loss can be experienced.

Frequent trips and falls can be seen. As time progresses, bathing and getting dressed cannot be done without any help.

In the final stages, you will require help to do everything. You will need day and night care.

When to consult a doctor?

Consult your doctor if you have emotional and mental changes. If you experience frequent mood swings, trips and falls, consult your doctor. Early diagnosis can help reduce the severity of the disease.

Conclusion

Huntington’s disease can have an impact on mental, emotional and social impact. During the final stages of Huntington’s disease, the person will require nursing care.

Currently, there is no cure for the disease, and medications can help reduce the severity of the disease. However, awareness about the disease can help reduce its occurrence of the disease.

Additionally, studies state that the medication for Huntington’s disease has succeeded at the cellular level.

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