Question: How Does The Mutant Huntingtin Proteins Do Their Damage?

What is the average life expectancy of a person with Huntington’s disease?

Huntington’s disease makes everyday activities more difficult to do over time.

How fast it progresses varies from person to person.

But the average lifespan after diagnosis is 10 to 30 years..

Why is Huntington’s disease rare?

In rare cases, HD is caused by a new ( de novo ) mutation in the HTT gene, in which case the disease occurs for the first time in the affected person and is not inherited from a parent. As HD is passed through generations, the size of the mutation in the HTT gene (called a trinucleotide repeat ) often increases.

Is Huntington disease a gain of function mutation?

Since people who have those repeats always suffer from Huntington disease, it suggests that the mutation causes a gain-of-function, in which the mRNA or protein takes on a new property or is expressed inappropriately.

What is mutant huntingtin protein?

Huntingtin (HTT) is now a famous protein because an abnormal expansion of a glutamine stretch (polyQ) in its N-terminal sequence leads to the devastating neurodegenerative disorder Huntington’s disease (HD). The gene encoding huntingtin, HTT, and its dominantly inherited mutation were identified more than 20 years ago.

What protein does Huntington’s disease affect?

Mutations in the HTT gene cause Huntington disease. The HTT gene provides instructions for making a protein called huntingtin. Although the function of this protein is unclear, it appears to play an important role in nerve cells (neurons) in the brain.

What does the huntingtin protein do?

Huntingtin is found in many of the body’s tissues, with the highest levels of activity in the brain. Within cells, this protein may be involved in chemical signaling, transporting materials, attaching (binding) to proteins and other structures, and protecting the cell from self-destruction (apoptosis).

Does everyone have the huntingtin gene?

Everyone has a gene that codes for huntingtin protein, a protein found in the cells of the body, which we will discuss later. Towards the beginning of this gene, the three-letter codon sequence C-A-G is repeated a few times. Each C-A-G sequence codes for the amino acid glutamine, a protein building block.

What famous person has Huntington’s disease?

Probably the most famous person to suffer from Huntington’s was Woody Guthrie, the prolific folk singer who died in 1967 at age 55. Ducks football coach Mark Helfrich’s mother also suffers from the disease and lives in a local nursing home.

What organs are affected by Huntington’s disease?

The disease mainly affects the brain and spinal cord and abnormal brain cells are mainly found in the areas deep down in the brain that control movement (caudate nuclei and striatum). All cells in the body use energy to live and carry out their functions.

How is Huntington’s disease diagnosed?

To diagnose Huntington disease, a healthcare practitioner may perform a neurological exam and ask about the person’s family history and symptoms. Imaging tests may be performed to look for signs of the disease and genetic testing can be done to determine if the person has the abnormal gene.

How does Huntington’s disease affect the cell?

Huntington’s disease is a rare, inherited disease that causes the progressive breakdown (degeneration) of nerve cells in the brain. Huntington’s disease has a broad impact on a person’s functional abilities and usually results in movement, thinking (cognitive) and psychiatric disorders.

Is Huntington’s disease loss of function?

While Huntington’s Disease is caused by a toxic gain of function due to polyQ expansion, multiple models suggest that a loss-of-function of the wildtype Htt protein may contribute significantly to several components of disease pathology (as summarized in Figure 2).