A genetic predisposition (or genetic susceptibility) isn’t the same as a genetic disease. It means there is an increased chance of developing a particular disease based on the individual’s genetic makeup. Generally, it takes up more than genetic predisposition as a contributing factor to trigger the disease.
These genetic changes in a person indicate that the person can develop a particular disease, but it is never guaranteed. Some people with genetic predisposition, do not tend to develop them during their lifetime.
An example of genetic predisposition: The presence of certain changes to BRCA1 or BRCA2 genes, greatly increases a person’s risk of developing breast cancer and ovarian cancer.
Having some genetic changes may increase the risk of developing a disease. However, having many gene changes within can combine and double the risk of developing several diseases such as diabetes, heart disease, even cancer. Lifestyle habits, environmental habits are also contributing factors of triggering a disease, and not genetic predisposition alone.