Huntigton Chorea

Huntington's chorea

Huntington's disease is an inherited disorder caused by the degeneration of certain nerve cells in the brain. Chorea is Greek word meaning dance like movements that can be accompany with the disease HD is an autosomal dominant disease which means only one copy of the faulty gene inherited from either mother or father is necessary for a person to develop the disease. Every person born to an affected parent has a fifty-fifty chance of either inheriting the faulty gene or not

Genes

The causative gene is located in chromosome number four genes are made up strings of nucleotides. The nucleotides are identified by the letters CAGT. Some genes such as the HD gene only have a string of three nucleotides. The sequence of these nucleotides CAGT tells the gene which protein to produce. The HD gene has a string of CAG which tells the gene to produce a protein called huntintin. On a healthy gene the number of repeats is anything from 10-34. A faulty HD gene has repeats of forty or more. On juvenile HD the repeat is more than 60 CAG. The severity of the disease is proportional to the number of extra residues

Symptoms

The symptoms of Huntington's disease begin insidiously. One half to three fourth of the patients present with abnormal movement rigidity. The remainder of the patients presents with mental status changes, such as irritability, moodiness, or antisocial behavior. All of the patients eventually exhibit chorea, which are jerky, random, uncontrollable, rapid movements. Typically, the abnormal movements begin at the extremities and then later progress to involve the trunk. Other symptoms exhibited by hd patients eventually include slurred speech, speech volume control issue, swallowing disorders frequently resulting in gagging and or choking, behavior problems, depression, loss of cognitive abilities, changes in personalities, and eventually develop mental deterioration leading to dementia. Initially, symptoms may present in most any order. Some patients first develop memory or other cognitive difficulties whereas others may develop chorea or slurred speech. HD patients may initially be highly functional in most capacities while only being diminished in a few. Approximately 10% of the patients have a juvenile form of hd. Typically, these patients present with muscular rigidity