Many diseases are devastating to the individual and their family. Huntington's disease [local] is particularly so because it involves a DNA mutation and symptoms are not apparent until well into the adult life, after children have been born. In these families, it has been a sort of 'roulette wheel' existence, waiting to find out if you will develop the disease and then knowing that you have probably passed it along to some of your children.

Progress in molecular genetics permitted scientists to locate the Huntington's disease defect on one end of human chromosome number four. Molecular biologists then 'walked' down the chromosome until they found a gene that was different between people that developed Huntington's disease and unaffected members of their family. This provided a diagnostic tool that permitted molecular screening [local] of people at any stage of their life. For those that find that they do not carry the defective gene, the fear of a tragic end from the disease is removed. Those that are found to harbour the gene must come to grips with this reality. Both will need counseling.