Huntington's Disease In 1872, George Huntington, American physician, researched and published a report on a disease that affected several generations of a family in East Hampton on Long Island. The clinical manifestations reflected Huntington’s disease (HD) with chorea, psychiatric and cognitive impairment and slow progression of deterioration leading to death. Huntington’s disease is an autosomal- dominant neurodegenerative disorder that is hereditary in nature. National Institute of Neurological Disorders and Stroke (2013) identified 15,000 Americans have HD. At least 150,000 Americans have 50% chance of developing the disease and relatives have the possibility of developing HD. The prevalence of HD is among populations of European decent between 3-7 cases per 100,000 remain stable between generations. Prevalence of HD is lower in Chinese, black African, and Japanese populations. Roze, Bonnet, Betuing, & Caboche (2010) reported in 1952, Venezuelan physician, Americo Negrette, suspected an epidemic of HD in a small town on Lake Maracaibo of Venezuela. The mean age for HD is 35-50 years; range is from 2-85 years. Fifteen percent of the cases occur before 30years. Life expectancy after the diagnosis of HD is approximately15-20 years. Wahlin & Byrne (2012) identified genetic markers through mapping of chromosomes of the gene that carries HD trait in 1983. Ten years later, causative HTT gene mutation of HD provided physicians the ability to predict whether asymptomatic individuals inherited the gene for future illness of individuals. Diagnosis of HD is diagnosed by the presence of clinical manifestations. Family members are challenged mentally and physically caring for persons with HD. Everyday life is complicated by... ... middle of paper ... ...is associated with instability of trinucleotide repeated on short arm of 4th chromosome. When 40 or more CAG repeats it reflects complete penetrant, all gene carriers present the illness, of HD. Partial penetrant suggest that carriers do not show signs of illness. When 36 to 40 CAG repeats in htt gene; complete penetrance of the disease is not successful related to instability of mutation then a full –length mutation occurs in the next generation representing HD. Thirty to thirty-five repeats of CAG indicates that the carrier will not exhibit the disease. A longer CAG repeat length presumable indicates transmission to the next generation. An unstable trinucleotide repeat is prominent in male gene carriers leading to HD in children of affected men and women occasionally. Mutation may arise for the first time in a family related to inherent instability.
Huntington's Disease and Its Ethics In “Genetics and Reproductive Risk: Can having children be immoral,” L.M Purdy discusses the notion that the recent advances in reproductive technology impose a moral obligation on individuals to prevent the birth of “affected” babies that will not have a “minimally satisfying life.” There are, however, several assumptions that the author makes in reaching the conclusion that having “affected” children is immoral. The author makes the claim that people with Huntington’s disease are unlikely to live a minimally satisfying life. It is known however, that Huntington’s disease does not take any affect until 40-50 years of age.
Many people, like myself, after watching an episode of “The Michael Jay Fox Show,” started to be come curious as to what exactly this disease is. You ask yourself; What is this disease? What causes it? Can it be passed down from generation to generation? Is there a treatment? What would your life be like suffering from this? Through my research on Parkinson’s disease, I am determined to answer these questions. I hope to have a better understanding on this disease, and how it affects the lives of patients that I might see in a hospital.
If Nathaniel Wu did not have the allele for Huntington’s disease, he would undeniably be the perfect scientist for the position in the eyes of the IPC. Wu is a 30-year-old microbiologist at one if the best research laboratories worldwide. After a series of interviews, the IPC was convinced his determination was not only factor that qualified him more in comparison to the other candidates; they realized that his potential “[is] likely to result in the type of discoveries for new drugs and treatments,” a goal that has not been reached since Dr. Peters’s incident. Wu is also known as a creative researcher and a hard worker, meaning that hiring him will likely result in a dramatic increase of earnings for the IPC. Considering that Huntington’s disease will most likely deteriorate Wu’s abilities, many may argue that it is not worthwhile to hire Wu; it is foreseen that the symptoms of Huntington’s disease begin to appear as soon as th...
Francis S. Collins is a renowned geneticist who originally became Ph.D in Physical Chemistry at Yale University and later on, a Medical Doctor at University of North Carolina. As soon as he graduated he was offered a fellowship in Human Genetics at Yale University under the guidance of Sherman Weissman, currently Sterling Professor of Genetics. In the late 1980’s Collins became known in the field of Medical Genetics for his development of positional cloning, a technique that allows to locate a hereditary disease-causing gene by studying the inheritance pattern within a family. Working with his method researchers found the genes responsible for diseases like Cystic fibrosis, Huntington’s disease, Neurofibromatosis, Multiple Endocrine Neoplasia type one, and Hutchinson-Gilford Progeria Syndrome. In 1993 Dr. Collins succeeded Dr. James D. Watson as the director of the National Human Genome Research Institute (NHGRI), overseeing the role of the United States in the mapping of the human genome. In 2009 President Obama personally recommended Collins to lead the National Institute of Health (NIH) where he works until present day. Francis S. Collins is by no means a bragging individual, bits and pieces of his accomplishments are scattered throughout the book and he makes no big deal about it; instead he j...
In 1993 a consortium of researchers who worked on the DNA samples from families in the Lake Maracaibo region of Venezuela, an area with a high density of HD and significant consanguinity, reported the successful discovery of the gene responsible for the occurrence of this disease, present in chromosome 4 and named it as IT15 (Interesting transcript #15). IT15 later called as the Huntingtin gene (HTT) [2]. HTT is ~10 kilobases (kb) long and translated into a protein of 3144 amino acids with anticipated molecular mass of 348 kDa. Huntigtin protein is expressed in in human and all mammalian cells, where brain and testis has the highest concentration; liver...
Myotonic dystrophy, type 1, is a genetic disorder which is linked to chromosome number 19 in humans. The dystrophia myotonica protein kinase gene is located on the q arm of the chromosome at the locus of 13.32. It is an autosomal dominant disorder, which means that the individuals that are affected by this disorder and contain at least one dominant allele for the dystrophia myotonica protein kinase gene. The disorder is caused by a series of repeats of a trinucleotide region that is expanded beyond the normal levels (Musova et al., 2009). The trinucleotide region is a series of repeats of CTG in the untranslated region of the dystrophia myotonica protein kinase gene. The severity of the disorder is associated with the number of repeats the individual has within the gene. Normal individuals tend to have between 5 and 37 repeats while an individual with a very mild myotonic dystrophy may have 50 to 150 repeats, and if the disorder is discovered at the time of birth the individual will have over 2,000 repeats of the trinucleotide region (Musova et al., 2009). Myotonic dystrophy, type 1, affects multiple organ systems of the body and is relatively slow to progress. Myotonic dystrophy, type 1, is categorized by alterations of the beating pattern of the heart, faulty dystrophin proteins, clouding of the lens of the eye, decreased functionality of the gonads, balding, and myotonia (Musova et al., 2009). Myotonia is described as the slow relaxation of any muscle type, which will cause the individual to use extended effort to simply relax the muscles after they have been contracted. Muscular dystrophy causes an individual to experience muscular deg...
Parkinson's is an idiopathic, multifactorial neurodegenerative disease that attacks neurotransmitters in the brain called dopamine. Dopamine is concentrated in a specific area of the brain called the substantia nigra. The neurotransmitter dopamine is a chemical that regulates muscle movement and emotion. Dopamine is responsible for relaying messages between the substantia nigra and other parts of the brain to control body movement. The death of these neurotransmitters affects the central nervous system. The most common symptoms are movement related, including shaking, rigidity, slowness of movement and difficulty with posture. Behavioral problems may arise as the disease progresses. Due to the loss of dopamine, Parkinson's patients will often experience depression and some compulsive behavior. In advanced stages of the disease dementia will sometimes occur. The implications of the disease on the anatomy and physiology of the respiratory and phonatory systems significantly control speech.
Lewis, Ricki, (2014), Human Genetics, 11th Edition, Chapter 12. Gene Mutation. [VitalSource Bookshelf Online]. Retrieved from
So if one parent has it, and passes the gene on to a child, that child will develop Huntington's disease if they live long enough and each of that child's' children will have a 50% chance of inheriting the gene, and so on and so forth. If you do not have the HD gene you can't pass it on to your children and if your mate doesn't have it then there is no way your child will develop the disease (spontaneous cases of HD are less than 0.1%). There are no "carriers" for Huntington's. HD is present in all areas of the world but is dominant in western Europeans and their descendants. In the United States every 1 in 10,000 people have developed HD, that's 300,000 people with another 150,000 at risk (all of those with children have a 50% chance of passing it on).
This disorder is caused by an inherited flaw on one gene (Mayo Clinic, 2010). Individuals in of western European around 1 in 20,000 are born with a gene that causes this disorder. Huntington’s disease is not as much common in areas such as Asia and Africa (Your Genes Your Health, 2012). People all over the world are affect by HD. HD is another way of saying Huntington’s disease. On Figure 1.0 you can see a person who has been affected with HD.
The video, “Cracking the Genetic Code,” brought for forth some great interest in knowing that the medical field and technology has advanced so much that we can know our own genetic code and if we will or develop a certain disease. But aside from the interest, the video also brought forth some heartbreaking moments for the patients in the video that have had their lives turned around due to medical illness. For example, Megan Sullivan, who was a fully functional young woman and started showing symptoms of Huntington’s disease during her college years, which reduced her functioning to where she can barely even speak for the interview. It’s hard seeing somebody that young go through those huge obstacles, or in the case of Catherine Ellton, who, in a way, was forced to speed up her life in a
Dementia can occur in relation to many different illnesses. Some of the most common of which are Huntington’s Disease,
James Parkinson first discovered Parkinson's Disease in 1817. Parkinson's Disease is a common neurologic disorder for the elderly. It is a disorder of the brain characterized by shaking and difficulty with walking, movement, and coordination. This disease is associated with damage to a part of the brain that controls muscle movement. Parkinson's Disease is a chronic illness that is still being extensively studied.
Since the gene for HD is dominant, there is a 50% chance of a sufferer's
Dementia is an organic brain syndrome which results in global cognitive impairments. Dementia can occur as a result of a variety of neurological diseases. Some of the more well known dementing diseases include Alzheimer's disease (AD), multi-infarct dementia (MID), and Huntington's disease (HD). Throughout this essay the emphasis will be placed on AD (also known as dementia of the Alzheimer's type, and primary degenerative dementia), because statistically it is the most significant dementing disease occurring in over 50% of demented patients (see epidemiology).