Information such as the number of relatives who've had a particular type of cancer, age of onset of the disease, and severity (e.g., multiple tumors) can help you determine whether a patient's at particularly high risk.
Drawing a pedigree is a useful way to spot these red flags. As you may remember, pedigrees use standard symbols to represent family history information. Pedigrees also allow you to visualize inheritance patterns,for example, whether a gene mutation is dominant, recessive, autosomal, or X-linked. You can review these symbols and how to draw a pedigree in the Videos & tutorials section of this lesson.
Your assessment of risk will lead you to clinical practice decisions. You'll learn more about this in Lesson 4.
Human chromosomes in a breast cancer cell
DNA people by Daniel Salaman
Human chromosomes in breast cancer cell by Paul J. Smith & Rachel Errington