Introduction
What is Huntington’s disease?
HUNTINGTON’S DISEASE is an inherited disorder that causes neurons in the brain to break down gradually and die. It is progressive and becomes worse as time goes by. This disease attacks areas of the brain that aid in regulation or control of voluntary movement and other important parts.
For proper management of Huntington’s disease, a team composed of the following healthcare providers in needed:
- A neurologist
- A psychiatrist
- A genetic counselor
- A speech therapist
- A physical therapist
- An occupational therapist
Key Facts & Statistics
It affects 7 out of every 100,000 persons globally.
Symptoms of HD start to present between 30-50 years old.
Risk Factors
Positive family history. If one of both parents has HD, there is 50% chance that there offspring will develop it.
Causes
Huntington’s disease is caused by a genetic mutation of the HTT gene, which is responsible for making protein huntingtin. Huntingtin helps neurons to function properly.
The defect in HTT gene cause DNA building blocks such as cytosine, adenine and guanine(CAG) to repeat many more times.
Most people have 27 or fewer CAG repeats in their HD gene, therefore not at risk of developing the disease. Individuals who have HD may have 36 or more CAG repeats.
In these individuals who have HD, their DNA lacks some of all the required information for making protein huntingtin. The resulting protein has abnormal shape and destroys neurons, leading the their deaths.
Neuronal destruction takes place in the basal ganglia or the part of the brain that controls movements of the body. In addition, the cortex that controls thought, memory and decision-making is also affected.
HD is inherited through autosomal dominant patter of inheritance, meaning that only one of both parents is needed to transfer the genetic mutation to an offspring.
Rarely, sporadic mutations occur where genetic changes take place in absence of previous history of HD in family line.
Signs & Symptoms
What are the signs and symptoms of Huntington’s disease?
- Involuntary and uncontrolled movements such as jerking and twitching(chorea).Chorea is sometimes referred to as uncontrollable dance-like movements.
- Loss of coordination.
- Loss of memory.
- Difficulty swallowing(dysphagia).
- Mood changes.
- Learning difficulties.
The following can develop as a result of HD:
- Emotional changes such as depression.
- Inability to focus and multitask.
Diagnosis
How is Huntington’s disease diagnosed?
Diagnosis is performed by neurologists.
Diagnosis involves:
- Physical and neurological examination
- Genetic testing for conformation. This test checks for changes in the HTT gene.
- Tests that rule out other conditions that present with similar symptoms as Huntington’s disease. Such tests are;
- Imaging tests like computed tomography scans and magnetic resonance imaging scans.
- Blood tests.
Treatment & Management
Is HD curable?
Currently, there is no treatment that is able to stop or reverse HD from manifesting, but some of the symptoms that present can be treated.
Several types of treatment are applied and this include:
- Physical and occupational therapy.
- Speech therapy.
- Counseling.
- Medications. Chorea associated with HD is treated with drugs such as haloperidol, tetrabenazine and deuterabenazine. E motional sypmtoms are treated with mod stabilizers(lithium), anti-depressants (fluoxetine)and anti-psychotic medications(risperidone and olanzapine).
Complications
What are the complications of Huntington’s disease?
Being a progressive disease, symptoms of this condition become worse over time. Complications can include worsening symptoms, such as:
- Infections like pneumonia.
- Difficulty eating and drinking. This can lead to malnutrition.
- Dementia(loss of memory and brain function).
Prevention
Can Huntington’s disease be prevented?
- Currently, there is no known methods or ways to prevent or reduce the risks of developing Huntington’s disease.
- Genetic counseling and testing for couples planning to get a baby to check for chances of having a baby with this condition.
- In-vitro fertilization(IVF) with genetic testing can help prevent this disease from being passed from parents to their offspring and future generations.