Molecular Genetics of Huntington’s Disease

Abstract

Huntington's disease is a neurodegenerative disorder of the brain that is caused by the mutation of the gene which produces a protein called huntingtin (htt). The mutation is based on the continuous repetition of the trinucleotide CAG which in turn makes the protein toxic for the brain cells. As a result neurons which contain the mutant protein begun to atrophy. The loss of those brain cells can cause many problems to the patients, even death. The aim of this paper is to report the problems caused to the brain by the mutant protein, specifically in the area of basal ganglia, the area that is the most affected by the disease, as well as the symptoms and metabolic changes to which the patient is subjected. Finally, the summary of the methods for a more timely and accurate diagnosis of the disease is based on these changes in order to simplify and facilitate the lives of inflicted people by means of the administration of the appropriate treatment.

Molecular basis of Huntington's disease and brain imaging evidence

“…The symptoms that primarily emerge are abnormal and involuntary movements, reduced thinking ability, memory loss, anxiety, irritability as well as depression, obsessive behavior and other mood changes [1]. Even though patients firstly show emotional or cognitive changes, the determinant factor of the onset of the disease is chorea [5].…”

“…M-htt's interaction with Rhes, which can only be found in the brain, is suspected to be the reason why huntingtin is only toxic for brain cells [1].…”

“…In Huntington's, the responsible gene (IT15) for the production of protein huntingtin is mutated causing and expanded repetition of the trinucleotide CAG. The produced polyglutamine strand is toxic for the brain [1].…”

“…At the early stages, patients show signs of chorea, bradykinesia as well as emotional changes like depression, anxiety, irritably etc. The brain region that is primarily affected by the disease is the region of basal ganglia, with other regions being affected as well [1]. Mutant huntingtin affects normal huntingtin's function leading to various problems in the cell as well as apoptosis.…”