We tend to resemble our parents because we inherit characteristics such as height and eye colour through the genes that they pass on. Many people become concerned that they may have inherited the gene for a disease, and that they may pass it on to their children. Alzheimer's disease is one of many conditions where there is a genetic factor in a small number of families. This information sheet outlines the present state of knowledge about inherited risk. There is no single gene for Alzheimer's disease.
Genetic factors are responsible for the disease in a small number of families.
In the wider community there is a genetic component to the disease, but inherited factors alone do not explain why some people develop it while others do not. The basic material of inheritance, DNA, is passed on in the form of genes, and delivered in packages called chromosomes, which are long chains of genetic instructions. We can think of DNA as being the letters of the alphabet, genes as the words they make up and chromosomes the sentences which convey meaning. We each inherit 23 pairs of chromosomes, one half of each pair from our mother and the other from our father. There are literally millions of combinations of genes we can inherit, and the effect of each gene is not yet known, although scientists worldwide are rapidly expanding our knowledge.