Barron’s Medical Journal Reporting Duke University Durham, NC USA
It was surprising to find out 70% of White Males contribute to suicide cases in the United States. Now with President Obama Health care plan in full effect and more Americans can get to a Doctor, one of the items of concern is Huntington’s disease. A genomics 
test that will find the HTT gene which maps to chromosome 4p16.3 aka (Huntington's Disease).
test that will find the HTT gene which maps to chromosome 4p16.3 aka (Huntington's Disease).
Huntington’s disease is an autosomal-dominant, progressive neurodegenerative disorder with a distinct phenotype, including chorea and dystonia, incoordination, cognitive decline, and behavioural difficulties. Typically, onset of symptoms is in middle-age after affected individuals have had children, but the disorder can manifest at any time between infancy and senescence. 
The mutant protein in Huntington’s disease—huntingtin—results from an expanded CAG repeat leading to a polyglutamine strand of variable length at the N-terminus. Evidence suggests that this tail confers a toxic gain of function. The precise pathophysiological mechanisms of Huntington’s disease are poorly understood, but research in transgenic animal models of the disorder is providing insight into causative factors and potential treatments.
The mutant protein in Huntington’s disease—huntingtin—results from an expanded CAG repeat leading to a polyglutamine strand of variable length at the N-terminus. Evidence suggests that this tail confers a toxic gain of function. The precise pathophysiological mechanisms of Huntington’s disease are poorly understood, but research in transgenic animal models of the disorder is providing insight into causative factors and potential treatments.
Huntington disease affects an estimated 3 to 7 per 100,000 people of European ancestry. The disorder appears to be less common in some other populations, including people
of Japanese, Chinese, and African descent.
of Japanese, Chinese, and African descent.
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 unknown, it appears to play an important role in nerve cells (neurons) in the brain. The HTT mutation that causes Huntington disease involves a DNA segment known as a CAG trinucleotide repeat. This segment is made up of a series of three DNA building blocks (cytosine, adenine, and guanine)
that appear multiple times in a row. Normally, the CAG segment is repeated 10 to 35 times within the gene. In people with Huntington disease, the CAG segment is repeated 36 to more than 120 times. People with 36 to 39 CAG repeats may or may not develop the signs and symptoms of Huntington disease, while people with 40 or more repeats almost always develop the disorder.
that appear multiple times in a row. Normally, the CAG segment is repeated 10 to 35 times within the gene. In people with Huntington disease, the CAG segment is repeated 36 to more than 120 times. People with 36 to 39 CAG repeats may or may not develop the signs and symptoms of Huntington disease, while people with 40 or more repeats almost always develop the disorder.
An increase in the size of the CAG segment leads to the production of an abnormally long version of the huntingtin protein. The elongated protein is cut into smaller, 
toxic fragments that bind together and accumulate in neurons, disrupting the normal functions of these cells. The dysfunction and eventual death of neurons in certain areas of the brain underlie the signs and symptoms of Huntington disease. Read more about the HTT gene.
toxic fragments that bind together and accumulate in neurons, disrupting the normal functions of these cells. The dysfunction and eventual death of neurons in certain areas of the brain underlie the signs and symptoms of Huntington disease. Read more about the HTT gene.
Huntington’s disease. In a cross-sectional study, about 9% of asymptomatic at-risk individuals contemplated suicide at least occasionally,11 perhaps a result of being raised by an affected parent and awareness of the disease. In the prediagnostic phase, the proportion rose to 22%, but in patients who had been recently diagnosed, suicidal ideation was lower. Brought To You By 2014 Cadillac ELR
The frequency increased again in later stages of the illness.11 The correlation of suicidal ideation with suicide has not been studied in people with Huntington’s disease, but suicide attempts are not in common. In one study, researchers estimated that more than 25% of patients attempt suicide at some point in their illness.18 Individuals without children might be at amplifi ed risk,19,20 and for these people access to suicidal means (ie, drugs or weapons) should be restricted. The presence of affective symptoms, specific suicidal plans, or actions that increase isolation (eg, divorce, giving away pets) warrants similar precautions.20.
A single abnormal gene, the basic biological unit of heredity, produces HD. Genes are composed of deoxyribonucleic acid (DNA), a molecule shaped like a spiral ladder. Each rung of this ladder is composed of two paired chemicals called bases. There are four types of bases, adenine, thymine, cytosine, and guanine, each abbreviated by the first letter of its name: A, T, C, and G. Certain bases always "pair" together, and different combinations of base pairs join to form coded messages. A gene is a long string of this DNA in various combinations of A, T, C, and G. . 
These unique combinations determine the gene's function, much like letters join together to form words. Each person has about 30,000 genes, a billion base pairs of DNA or bits of information repeated in the nuclei of human cells, which determine individual characteristics or traits. This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. An affected person usually inherits the altered gene from one affected parent. In rare cases, an individual with Huntington disease does not have a parent with the disorder.
These unique combinations determine the gene's function, much like letters join together to form words. Each person has about 30,000 genes, a billion base pairs of DNA or bits of information repeated in the nuclei of human cells, which determine individual characteristics or traits. This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. An affected person usually inherits the altered gene from one affected parent. In rare cases, an individual with Huntington disease does not have a parent with the disorder.
As the altered HTT gene is passed from one generation to the next, the size of the CAG trinucleotide repeat often increases in size. A larger number of repeats is usually associated with an earlier onset of signs and symptoms. This phenomenon is called anticipation. People with the adult-onset form of Huntington disease typically have 40 to 50 CAG repeats in the HTT gene, while people with the juvenile form of the disorder tend to have more than 60 CAG repeats. Individuals who have 27 to 35 CAG repeats in the HTT gene do not develop Huntington disease, but they are at risk of having children who will develop the disorder. As the gene is passed from parent to child, the size of the CAG trinucleotide repeat may lengthen into the range associated with Huntington disease (36 repeats or more).uncommon. In one study, researchers estimated that more than 25% of patients attempt suicide at some point 
in their illness.18 Individuals without children might be at amplified risk,19,20 and for these people access to suicidal means (ie, drugs or weapons) should be restricted. The presence of affective symptoms, specific suicidal plans, or actions that increase isolation (eg, divorce, giving away pets) warrants similar precautions.20.
in their illness.18 Individuals without children might be at amplified risk,19,20 and for these people access to suicidal means (ie, drugs or weapons) should be restricted. The presence of affective symptoms, specific suicidal plans, or actions that increase isolation (eg, divorce, giving away pets) warrants similar precautions.20.
In genetics, a chromosome translocation is a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes. A gene fusion may be created when the translocation joins two otherwise-separated genes, the occurrence of which is common in cancer. It is detected on cytogenetics or akaryotype of affected cells. 
Translocations can be balanced (in an even exchange of material with no genetic information extra or missing, and ideally full functionality) or unbalanced (where the exchange of chromosome material is unequal resulting in extra or missing genes) Neuropathological changes in Huntington’s disease are strikingly selective, with prominent cell loss and atrophy in the caudate and putamen.33–35 Striatal medium spiny neurons are the most vulnerable. Those that contain enkephalin and that project to the external globus pallidum are more involved than neurons that contain
substance P and project to the internal globus pallidum.33,34 Interneurons are generally spared. These findings accord with the hypothesis that chorea dominates early in the course of Huntington’s disease because of preferential involvement of the indirect pathway of basal ganglia-thalamocortical circuitry.11
Translocations can be balanced (in an even exchange of material with no genetic information extra or missing, and ideally full functionality) or unbalanced (where the exchange of chromosome material is unequal resulting in extra or missing genes) Neuropathological changes in Huntington’s disease are strikingly selective, with prominent cell loss and atrophy in the caudate and putamen.33–35 Striatal medium spiny neurons are the most vulnerable. Those that contain enkephalin and that project to the external globus pallidum are more involved than neurons that contain
substance P and project to the internal globus pallidum.33,34 Interneurons are generally spared. These findings accord with the hypothesis that chorea dominates early in the course of Huntington’s disease because of preferential involvement of the indirect pathway of basal ganglia-thalamocortical circuitry.11
Other brain areas greatly affected in people with Huntington’s disease include the substantia nigra, cortical layers 3, 5, and 6, the CA1 region of the hippocampus,36 the angular gyrus in the parietal lobe,37,38 Purkinje cells of the cerebellum,39 lateral tuberal nuclei of the hypothalamus,40,41 and the cells.
