Huntington's Disease
Huntington's Disease is a genetic autosomal disorder which effects the brain. It affects about 1 in 20,000 individuals. The symptoms of the disease do not start to occur until after or around 40 years of age. With the onset of the disease the patient starts to gradually deteriorate intellectually, this deterioration also causes involuntary movements. Scientists have only recently found the section of the gene which causes Huntington's disease, and this is allowed them to devise pre-symptomatic tests. However, a cure for the disease is yet to be found.
Symptoms
The symptoms of the Huntington's disease vary from person to person. They can be grouped in two categories: Abnormal involuntary movements and
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It is said that Huntington's disease was first introduced to Australia by a Somerset woman who arrived in Tasmania aboard the "Arab" ship in 1842. She had thirteen children; eight with her first husband and five with her second. Five of the six females and four of the seven males inherited the disease.
Causes of the Disorder
This disease is genetically inherited and is a dominant characteristic, therefore unfortunately the offspring of a victim has 50% chance of inheriting the disease.
The DNA contains four types base: A (adenine) and T (thymine), G (guanine) and C (cytosine). These four letters make up the genetic alphabet and they spell out the commands for every single cell and organ of the body and also determine all the characteristics of the person.
In 1993 it was discovered that a segment of DNA on the arm of chromosome 4 is linked to the HD gene. They found that at one end of the HD gene, the combination CAG is repeated too many times. In people without HD this CAG is repeated 5 to 35 times. In people who are affected by HD, CAG is repeated over and over again between 36 and 121 times.
The CAG combination codes for a protein called huntingtin. Why the increase number of CAG causes HD is still unknown. It is thought that too much of the HD protein makes them obtain some new, abnormal property. This is true in two
George Huntington first described Huntington’s disease in 1872, but it was only mentioned to the
Huntington’s disease would affect motor movements such as doing jerks and twitches. Tremors would spread and gradually interfere with walking, speech, and other voluntary movements.
The three most profound behavioral problems in Huntington 's disease come from the uncontrollable movements called "chorea," dementia, and the altered perception of the
Huntington’s disease is caused by a mutation in the gene for a protein called Huntingtin. The genetic mutation results in the building blocks of DNA (cytosine, adenine, and guanine) to be replicated many more times than in an average individual. As a result, Huntington’s disease breaks down brain cells, or neurons, specifically located in the primary motor cortex regions of the brain, but can effect other brain areas
The movement disorders associated with Huntington's disease can include both involuntary movements and impairments in voluntary movements:
If the disease is of the homozygous variety in a person it occurs in 1 in every 10,000 people. If the disease is heterozygous then in is found between 1 in every 5,000 people and 1 in every 15,000 people. It is more common in Venezuela then anywhere else, although it is discovered in about 240 people per year in the United States. A DNA marker G8 (D4S10) is closely linked to HD and has been identified as being on the # 4 chromosome and can detect Heterozygotes. (Encarta Encyclopedia) The connection between G8 and HD has not been clinically used because it’s a very serious disease. Theoretically a homozygote can be detected parentally. If a female has a child and she is tested positive for HD and has no history of it, then the father as well as the child a bound to end up with the disease. (Textbook
The clinical features of Huntington's disease can be thought of as a triad of emotional, cognitive and motor disturbances. Symptoms include chorea (dance-like involuntary movements), clumsiness, slurred speech, depression, irritability, and apathy. Cognitive losses may include attention, intellectual speed, and short-term memory.
Researchers believe that this specific gene is involved with the formation of a structure called the junctional membrane complex, which connects specific channels in the cells with other channels in the surface of the cell. This complex is involved with charged calcium atoms, which is crucial for transferring signals in cells. Juntophillin-3 is most likely involved with signaling in between neurons in the brain. A specific kind of mutation in the JPH3 gene has been found to cause some symptoms and signs that is alike with those who have HD. Researches have named this condition Huntington Disease-Like 2, or HDL 2. The mutation with HDL 2 increases the size of a DNA segment known as CAG/CTG trinucleotide repeat in JPH3. People with HDL2 have 44 to 59 repeats, and people with 29 to around 43 repeats have are not likely to develop signs and symptoms of this condition. Researchers believe that JPH3 gene produces a changed version of messenger RNA. The altered messenger RNA begins to form clumps in neurons that interfere with normal functions of the cells, and eventually lead to the death of neurons throughout the brain which show signs and symptoms of HDL2 (Huntington disease-like
Huntington Disease is a rare inherited Neurological illness. This illness is passed down from generation, but may not show up until you are an adult and is may no never show up. It often appears in more than one member if it occurs in a family. This a Genetic Condition. The change in the genetic information that is passed down is what causes Huntington's Disease. This illness causes involuntary movements, severe emotional disturbance. Huntington causes parts of the brain to break down and lose some natural functions and affects the Nervous system. The very first noticeable symptoms of this illness in changes in personality and muscle twitches. You would usually start to notice these symptoms around the age of 30 to 50. The men and women with
Huntington’s disease, named after George Huntington, was discovered in 1872. It is a neurological condition that is caused by an altered gene. This gene is passed from parent to child, but the disease cannot be seen until a later age. As the disease affects the brain by death of brain cells, the patient loses thinking. Also loss of physical and emotional functions such as walking, feeling pain, and lack of display of emotion. The symptoms start to appear when adults are around the age of 30 as well as up to 70. The most common symptom of Huntington’s is chorea. Chorea is where the body jerks, usually in the arms and legs. They may also experience difficulty speaking, swallowing, and focusing.
HCM can present at any age and can affect any race and gender. It is inherited in an autosomal dominant Mendelian pattern, variable expressivity, age-related penetrance, and incomplete penetrance. The probability of affected individuals passing the mutation and risk for the disease on to their offspring is 50 percent. However, de novo mutations may also be present in the proband, and lead to sporadic cases of the disease.
Named after George Huntington, Huntington’s Disease is a hereditary neurodegenerative disease. It “causes the death of specific neurons in the brain, leading to jerky movements, physical rigidity, and dementia (First).” The mutation was first mapped to chromosome 4 in 1983, becoming the first disease gene to be mapped using DNA polymorphisms (First). In 1993, a group of investigators found the gene that causes Huntington’s Disease. It is caused by a mutation in a gene located on chromosome 4 (Mennitto). The gene contains an abnormally large number of CAG (Mennitto). The gene may lengthen when passed from father to child, but not mother to child (Mennitto).
Symptoms of Huntington’s disease typically become noticeable between the ages of 35 and 44 years. In the early stages of the onset of the disease, the physical symptoms are usually the first to be recognized and the onset, progression, and extent of the cognitive and behavioral symptoms vary between patients. The most characteristic initial physical symptoms are involuntary, quick, irregular jerking movements, which is called chorea. Chorea may be initially exhibited as general restlessness, lack of coordination, or unintentionally initiated motions. Normally, chorea precedes other signs of motor dysfunction by at least three years. The more severe motor abnormality, dystonic posturing, commonly appear as the disease progresses and are clear
Early symptoms of the disease are usually subtle in presentation and are often misdiagnosed in the early stage of the disease. The symptomology includes alterations of personality, mood or mental capabilities. People affected by Huntington’s disease gradually exhibit a lack of coordination followed by an unsteady posture and gait resulting in the inability to even stand still. This behavior could mimic other diseases such as a stroke, multiple sclerosis, or Parkinson’s disease. (Alz.org, 2016) As the disease progresses the physical effects on the body become more apparent and pronounced. This includes a decreased ability to walk or talk. Movements become jerky and uncoordinated making even the smallest tasks such as buttoning a shirt, nearly impossible.
Late stage. In this stage, people with Huntington's must depend on others for their care. Walking and speaking is very difficudlt, it might not be possible, Most likely the individual will still be aware of loved ones around them. Fidgety movements may become