New mutations in gene that increase breast cancer identified

According to a study published in the American Journal of Human Genetics, mutations in a gene called XRCC2 cause increased breast cancer risk. The study looked at families that have a history of the disease but do not have mutations in the previously known breast cancer susceptibility genes. Many breast cancer cases appear in families with a weak history of the disease. The research studied a population with a weaker family history and coincidentally, a very rare gene mutation. Using a technology called exome sequencing that shows the exact order of the nucleotides in all the protein coding genes in the human genome, the researchers found two different types of XRCC2 mutations that occur in breast cancer patients. One type of mutation causes the gene to create an incomplete version of the protein, causing it to be dysfunctional. The other type occurs when a single amino acid in the protein is changed.