Question

What is true about the national history and epidemiology of \(\mathbf{H D}\) ? a. Men are affected more than woman. b. It is an inherited genetic disorder where an accurate test is not available. c. Description of the disease complex was ascribed to Frederick Huntington in \(1972 .\) d. All of the above. e. None of the above

Short answer

Answer: None of the above.

Step-by-step solution

Evaluate option (a)

According to various scientific research and data available on Huntington's Disease, this disease affects men and women equally. It doesn't discriminate based on gender. Therefore, option (a) is not true.

Evaluate option (b)

Huntington's Disease is indeed an inherited genetic disorder that is caused by a mutation in the individual's HTT gene. However, there is an accurate genetic test available today to diagnose this disease. A person can undergo genetic testing to find out if they carry the mutated gene responsible for causing HD. Therefore, option (b) is not true either.

Evaluate option (c)

The description of the disease complex was ascribed to George Huntington, not Frederick Huntington. Furthermore, George Huntington published his paper on the disease in 1872, not 1972 as mentioned in the statement. Therefore, option (c) is not true.

Evaluate option (d) and (e)

Since none of the individual statements (a), (b), and (c) are true, option (d) "All of the above" cannot be the correct answer. The only remaining option is (e) "None of the above," which is the correct answer for this exercise. The correct answer is: (e) None of the above.

Key concepts

Genetic Disorder

Huntington's Disease (HD) is a genetic disorder, meaning it is caused by changes or mutations in genes passed on from one generation to the next. In the case of HD, the mutation occurs in the HTT gene, which provides instructions for making a protein called huntingtin. This gene is located on chromosome 4. Everyone has two copies of this gene, one from each parent. However, the mutated version leads to the production of an abnormal form of the protein, which is toxic to certain brain cells, leading to the symptoms associated with Huntington's Disease.

Huntington's Disease is autosomal dominant. This means that having just one copy of the mutated gene from one parent is enough to cause the disorder. People who have a parent with HD have a 50% chance of inheriting the faulty gene and thus developing the disease. Because of its genetic nature, families with a history of HD may choose to undergo genetic testing to find out if they have inherited the mutation.

• Mutation in HTT Gene: Causes abnormal protein production.
• Autosomal Dominant: Each child has a 50% chance of inheriting the gene from an affected parent.
• Genetic Testing: Allows individuals to know if they carry the mutated gene.

Epidemiology

The epidemiology of Huntington's Disease involves understanding how the disease affects populations. HD is considered a rare genetic disorder. However, it is more common in European populations compared to those of Asian or African descent. The estimated prevalence is around 5-10 cases per 100,000 people in western countries, making it rare but not extraordinarily so.

Huntington's Disease typically manifests between the ages of 30 and 50. This period is known as the "adult-onset" phase. There is also a less common "juvenile-onset" form where symptoms can appear before the age of 20. Both forms progress relentlessly, affecting movement, cognition, and emotions, leading to a decline in quality of life.

• Prevalence: Affects 5-10 per 100,000 in Europe and Western countries.
• Adult-Onset: Symptoms usually start between ages 30-50.
• Juvenile-Onset: Rare form that begins before age 20.

Gender Equality in Disease

Understanding the distribution of Huntington's Disease between genders is important. HD affects both males and females equally. This means that the likelihood of inheriting and expressing the symptoms of the disease is not influenced by a person's gender. This equal distribution can be explained by the autosomal nature of the HTT gene mutation, which is not located on a sex chromosome.

It is crucial to refute the misconception that men are more affected than women. Such inaccuracies can lead to gender-biased assumptions and fear, impacting the perceptions of those affected and possibly influencing healthcare decisions. By recognizing HD as a genetically inherited disorder not linked to gender differences, awareness and education campaigns can build a more accurate understanding of the disease across society.

• Equal Impact: Both men and women have an equal chance of inheriting HD.
• Autosomal Nature: The HTT gene is located on chromosome 4, not a sex chromosome.
• Awareness: Dispelling myths leads to better understanding and support.