Mutation means that there is a change in the genomic sequence of an organism. This can be either in the DNA or the RNA. Mutations can occur for a number of reasons, including radiation, viruses, transpons, and mutagenic chemicals. There may also be an error that occurs during the processes of replication or meiosis. A mutation may or may not effect the way an organism functions.
Mutations can most certainly occur in diseases. You may have even heard about diseases mutating on the news. For example, the swine flu or H1N1 flu is a mutation of influenza. In order for a virus to infect someone, the virus has to attach to cells in the host organism's body. Over time, the cells become immune to the virus and the virus is not able to attach. As a result, the virus evolves so that it is able to attach to a cell again.
Within the cells of the human body many complex interactions take place that regulate and express human genes. Changes in the structure and function of a gene and the process of protein synthesis may affect a person’s health. A permanent change in the structure of DNA is called a mutation. Most of the time DNA changes either have no effect or else cause harm. Sometimes a mutation can improve an organism's chance of surviving and passes the beneficial change on to its descendants. There are several different types of gene mutations. These include: deletion (loss), duplication (multiplication), inversion, insertion (addition), translocation (rearrangements), and point mutations (changes in base pair sequences).
Genetic and genomic discoveries have led to the development of an increasing number of genetic tests that can be used to identify a trait, diagnose a genetic disorder, and/or identify individuals who have a genetic predisposition to diseases, such as cancer or heart disease. There is now genetic testing for more than 1,600 genetic disorders ranging from single-gene disorders, such as cystic fibrosis, to complex disorders, such as diabetes