Final answer:
In some families, members can inherit a mutant allele that increases their predisposition to cancer. This means they have a genetic tendency or susceptibility to develop the disease.
Step-by-step explanation:
In some families, members inherit a mutant allele that causes a predisposition to cancer. A predisposition is a genetic tendency or susceptibility to develop a disease. In the case of cancer, inheriting a mutant allele can increase the likelihood of developing the disease. This is often related to defects in tumor suppressor genes, such as BRCA1 and BRCA2, which increase the risk for cancers like breast and ovarian cancer. Inherited mutations play a role in about 5 to 10 percent of all cancers and can lead to increased risk even though not all individuals with these mutations will necessarily develop cancer. Environmental factors also influence cancer risk. It is important to be aware of family medical history and consider genetic testing when a pattern of cancer is evident across generations in a family.
For example, in certain families, mutations in the genes BRCA1 and BRCA2 can increase the predisposition to breast and ovarian cancers. These mutated alleles can be inherited from one or both parents and individuals with these mutations have a higher risk of developing cancer compared to those without the mutation.
It's important to note that while inheriting a mutant allele increases the risk, it doesn't guarantee that an individual will develop cancer. Other factors, such as environmental exposures and lifestyle choices, also play a role.