Common Genetic Terms

Cancer risk assessment The process of evaluating and interpreting an individual’s chance to develop cancer based on personal and/or family history of medical conditions, exposures, and/or cancers.

First degree relatives Those persons with a direct, close blood relationship such as mother, father, brothers, sisters and children.

General population risk Refers to persons who are not known to have any medical conditions, family history of cancer or specific exposures that would increase the risk of developing certain type/s of cancer.

Genes  The units of instruction in most cells of our body that control our normal growth and development.

Gene mutation  A change or alteration in a gene which affects the gene's ability to function normally.

Genetic counseling  At RPCI, this is a service provided by health care professionals with specialized graduate degrees and experience in the areas of medical genetics and counseling. During a genetic counseling consultation, information and support is provided to individuals who have a personal or family history of cancer and who may be at risk for an inherited condition. Information gathered is interpreted in terms of the risk for specific cancers, assessment for an inherited cancer susceptibility syndrome, risk to children and other relatives, and options for screening and genetic testing.

Genetic pedigree A diagram of a family tree representing the ancestral history. See below.

Genetic testing  Allows for the possible identification of a change in a gene, which may play a role in the development of or risk for cancer or other medical conditions.

Increased risk  Refers to persons who have, or are suspected to have, a higher likelihood (compared to the general population) of developing a certain cancer/s due to personal and/or family history of medical conditions, exposures, and/or cancers.

Inherited (inheritance) - Refers to characteristics or qualities we receive from our parents as a result of their passing on genes contained in their egg or sperm cells.

Inherited susceptibility to cancer  The transmission of a changed or mutated cancer susceptibility gene from parent to child through the egg or sperm. One who inherits a mutated cancer susceptibility gene has an increased risk (above the general population risk) to develop cancer. This does NOT imply that the person has a predisposition or a 100% chance to develop cancer.

Maternal relatives  Those persons who share a blood relationship with the mother’s side of the family.

Paternal relatives Those persons who share a blood relationship with the father's side of the family.

Registries Compiled data on individuals and families with cancer. Selected persons may choose to join a registry. The Clinical Genetics Service works with the cancer registries at RPCI including colorectal, breast, ovarian, pancreas and sarcoma. A genetic registry of families with non-site specific cancers is also being developed. Registry participants may be candidates to participate in research studies to better understand cancer and its genetic basis, which may ultimately lead to treatments and cures for cancer.

Second degree relatives  Those persons with a less direct, but close blood relationship such as aunts, uncles, nieces, nephews, grandparents and grandchildren.