Huntington's Disease Association Fact Sheet 3 Predictive Testing for Huntington's Disease Huntington's disease is an hereditary disorder of the central nervous system. It is caused by a faulty gene. If one of your parents or another relative has Huntington's disease then you will probably be wondering about the likelihood of developing the disease yourself. One of each pair of autosomes comes from your father and one from your mother.
Chromosomes contain genes which are the basic units of inheritance.
The gene for Huntington's disease is on chromosome 4. People with Huntington's disease have one 'good' copy of the gene and one faulty copy. When they have children they may pass on the 'good' copy or they may pass on the faulty copy. Sometimes this is called a '1 in 2 chance' of developing the disease. If you have the faulty gene you will, at some stage, develop the disease.