Duplication - Where a part of a chromosome or gene is duplicated. Enzyme - A protein that triggers chemical reactions. Gene therapy - A potential method of treatment for genetic disorders which involves making correct copies of the gene in question and then transporting them into the cells of the body. The coded instructions that govern the make-up of every human being. Each gene carries instructions for the production of a specific protein.
Genes usually come in pairs one inherited from each parent.
They are passed on from one generation to the next and are the basic units of inheritance. Genetic counsellng - information and support provided by a specialist usually a doctor or nurse to people who have genetic conditions in their families or who are concerned about the future possibility of genetically transmuted conditions. Genetic markers - Harmless variations in the DNA which lie close to the site of a disrupted gene which may be used for tracking the condition through a family. Linkage studies - These are tests carried out on various family members to establish which is the crucial bit of genetic code causing a particular condition in that family. Muscle fibre - The basic unit of muscle tissue formed by the fusion of groups of muscle cells.