Huntington's disease

Definition

Huntington's disease is a hereditary neurodegenerative disorder characterized by the progressive breakdown of nerve cells in the brain, leading to severe physical and mental decline. This condition is caused by a mutation in the HTT gene, which results in the production of an abnormal version of the huntingtin protein, ultimately causing neuronal death. The disease typically manifests in mid-adulthood and leads to a range of symptoms that impact movement, cognition, and behavior.

5 Must Know Facts For Your Next Test

1. Huntington's disease usually appears between the ages of 30 and 50, but can occur earlier or later in life.
2. The genetic mutation responsible for Huntington's disease involves an expansion of CAG repeats in the HTT gene, with more than 36 repeats leading to the disorder.
3. Symptoms include movement disorders like chorea, cognitive decline such as memory loss and difficulty concentrating, and psychiatric issues like depression and anxiety.
4. There is currently no cure for Huntington's disease, but treatments focus on managing symptoms and improving quality of life.
5. Genetic testing can determine if a person carries the mutated HTT gene, allowing for early diagnosis and family planning considerations.

Review Questions

• What are the main symptoms associated with Huntington's disease, and how do they affect daily living?
  • Huntington's disease primarily presents with movement disorders such as chorea, which leads to involuntary jerky movements. Additionally, cognitive symptoms such as difficulty with memory and problem-solving can hinder daily tasks. Psychiatric symptoms like depression or anxiety may also arise, impacting social interactions and overall quality of life. These combined effects can make it challenging for individuals to maintain independence and engage fully in daily activities.
• Discuss the implications of Huntington's disease being an autosomal dominant disorder for affected families.
  • Since Huntington's disease is an autosomal dominant disorder, each child of an affected parent has a 50% chance of inheriting the mutated gene. This genetic certainty can create significant emotional and ethical dilemmas for families, as they navigate decisions around genetic testing and family planning. Furthermore, knowing the likelihood of inheriting the condition can influence psychological well-being, as potential future challenges associated with the disease loom over family dynamics.
• Evaluate current treatment options for Huntington's disease and their effectiveness in managing symptoms.
  • Current treatments for Huntington's disease focus on symptom management rather than curing the condition. Medications can help control chorea and psychiatric symptoms but do not halt disease progression. For example, antipsychotics may reduce involuntary movements and improve mood, while antidepressants can assist with emotional challenges. However, these treatments often come with side effects and may not work equally well for everyone. Ongoing research aims to find more effective therapies that address both symptoms and underlying mechanisms of neurodegeneration.

Related terms

Chorea: Chorea refers to the involuntary, irregular movements that are a hallmark symptom of Huntington's disease, making it difficult for individuals to control their actions.

Autosomal Dominant: Huntington's disease follows an autosomal dominant inheritance pattern, meaning that only one copy of the mutated gene from an affected parent can lead to the disease in offspring.

Neurodegeneration: Neurodegeneration describes the gradual loss of neuron function and structure, which is a key feature of Huntington's disease as well as many other neurodegenerative conditions.