We all have 46 chromosomes in our cells. Chromosomes are made from DNA (deoxyribonucleic acid). Genes are short sections of DNA and each chromosome contains many genes. Genes contain the information our bodies need to make proteins, which play an important role in the processes that keeping our body working normally. Sometimes a gene may change (this is called a mutation) and either cause or increase the risk of a disease. See also the separate leaflet on Genetic Testing for further information.
This is a companion discussion topic for the original article at https://patient.info/cancer/brca-genes