Huntington's disease, is a rare hereditary neurological disorder that affects up to 8 people in each group of 100,000. It is named after the physician George Huntington of Ohio, who described it precisely in 1872. The disease has been widely studied in recent decades. In 1993 the gene that causes the disease was discovered.
The most obvious symptoms of the disease are abnormal body movements and lack of coordination, also affecting various mental abilities and some personality aspects. Being a genetic disease, currently has no cure, however symptoms can be minimized with the administration of medication.
Huntington's disease is a degenerative disease that affects the central nervous system and causes involuntary movements of the arms, legs and face. These movements are quick and sudden gestures. Is hereditary disease, caused by a genetic mutationand the affected person's child has a 50% probability of developing it. If a descendant does not inherit the disease gene, it will not develop it or transmit it to the next generation.
DNA is made up of chemicals called nucleotides, the individual who has this disorder presents in its genetic material abnormal repeats of the nucleotide sequence cytosine, adenosine and guanine (CAG), responsible for coding glutamine. In person is the sequence CAG is found with repetitions less than 20; Already in people with Huntington's disease there are always more than 36 repetitions, thus making the gene defective.
Although each cell in the body has two copies of each gene, one copy of the abnormal gene is sufficient to have this disease. So it can be said that the gene that conditions Huntington's disease is a dominant gene. The study of chromosome 4 allowed us to discover the nature of the disease and to allow it to be diagnosed when it is still asymptomatic.