Htt gene mutation

Definition

The htt gene mutation refers to a specific alteration in the HTT gene, which encodes the huntingtin protein. This mutation is most famously associated with Huntington's disease, a progressive neurodegenerative disorder characterized by motor dysfunction, cognitive decline, and psychiatric symptoms. The mutation typically involves an expansion of CAG repeats within the gene, leading to an abnormally long polyglutamine sequence in the huntingtin protein, which ultimately disrupts normal cellular functions.

5 Must Know Facts For Your Next Test

1. The htt gene is located on chromosome 4 and mutations result in an abnormal huntingtin protein that aggregates in neurons.
2. Symptoms of Huntington's disease typically appear between ages 30 and 50, but can manifest earlier or later depending on the individual.
3. Diagnosis of Huntington's disease often involves genetic testing to identify the presence of the htt gene mutation.
4. Management of Huntington's disease focuses on symptomatic relief, as there is currently no cure to reverse the effects of the mutation.
5. Research continues to explore potential therapies that could target the underlying mechanisms of the htt gene mutation and its impact on neuronal health.

Review Questions

• How does the htt gene mutation specifically contribute to the development of Huntington's disease?
  • The htt gene mutation leads to an expansion of CAG repeats within the HTT gene, resulting in a huntingtin protein that is abnormally long. This altered protein accumulates in neurons and disrupts various cellular functions, ultimately causing cell death. As these affected neurons are critical for movement control and cognitive function, their loss leads to the characteristic symptoms of Huntington's disease, including chorea and cognitive decline.
• Discuss the implications of genetic testing for families at risk for Huntington's disease due to the htt gene mutation.
  • Genetic testing for families at risk can provide crucial information regarding whether individuals carry the htt gene mutation. This knowledge allows for informed family planning and early intervention strategies. However, it also raises ethical considerations regarding psychological impact and potential discrimination. The choice to undergo testing is deeply personal and can significantly affect family dynamics and individual mental health.
• Evaluate the current research approaches aimed at addressing the consequences of the htt gene mutation in Huntington's disease.
  • Current research approaches include exploring gene silencing techniques that aim to reduce levels of the mutant huntingtin protein. Additionally, scientists are investigating potential neuroprotective agents that may prevent neuronal death associated with this mutation. Furthermore, advancements in stem cell therapy are being considered to replace damaged neurons. These strategies show promise in addressing both symptomatic relief and targeting the underlying causes of Huntington's disease, aiming for more effective treatments in the future.

Related terms

Huntington's Disease: A genetic disorder caused by the htt gene mutation, leading to progressive degeneration of nerve cells in the brain.

Polyglutamine Disease: A category of disorders caused by CAG repeat expansions, including Huntington's disease and several other neurodegenerative conditions.

CAG Repeat Expansion: An increase in the number of CAG trinucleotide repeats in certain genes, linked to various genetic disorders including Huntington's disease.