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Huntingtons Disease
| Term Paper Title |
Huntingtons Disease |
| # of Words |
1008 |
| # of Pages (250 words per page double spaced) |
4.03 |
Huntington's Disease
Huntington's Disease
Background
Huntington's disease is inherited as an autosomal dominant disease that gives
rise to progressive, elective (localized) neural cell death associated with
choleric movements (uncontrollable movements of the arms, legs, and face) and
dementia. It is one of the more common inherited brain disorders. About 25,000
Americans have it and another 60,000 or so will carry the defective gene and
will develop the disorder as they age. Physical deterioration occurs over a
period of 10 to 20 years, usually beginning in a person's 30's or 40's. The gene
is dominant and thus does not skip generations. Having the gene means a 92
percent chance of getting the disease. The disease is associated with increases
in the length of a CAG triplet repeat present in a gene called 'huntington'
located on chromosome 4. The classic signs of Huntington disease are progressive
chorea, rigidity, and dementia, frequently associated with seizures. Studies &
Research Studies were done to determine if somatic mtDNA (mitochondria DNA)
mutations might contribute to the neurodegeneration observed in Huntington's
disease. Part of the research was to analyze cerebral deletion levels in the
temporal and frontal lobes. Research hypothesis: HD patients have significantly
higher mtDNA deletionlevels than agematched controls in the frontal and temporal
lobes of the cortex. To test the hypothesis, the amount of mtDNA deletion in 22
HD patients brains was examined by serial dilution-polymerase chain reaction
(PCR) and compared the results with mtDNA deletion levels in 25 aged matched
controls. Brain tissues from three cortical regions were taken during an autopsy
(from the 22 HD symptomatic HD patients): frontal lobe, temporal lobe and
occipital lobe, and putamen. Molecular analyses were performed on genetic DNA
isolated from 200 mg of frozen brain regions as described above. The HD
diagnosis was confirmed in patients by PCR amplification of the trinucleotide
repeat in the IT 15 gene. One group was screened with primers that included
polymorphism and the other was screened without the polymorphism. After heating
the reaction to 94 degrees C for 4 minutes, 27 cycles of 1 minute at 94 degreesC
and 2 minutes at 67 degrees C, tests were performed. The PCR products were
settled on 8% polyacrylamide gels. The mtDNA deletion levels were quantitated
relative to the total mtDNA levels by the dilution-PCR method. When the
percentage of the mtDNA deletion relat
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