If you have ever attended a family reunion, you know how conversations in families can revolve around health. There is almost always that one family member who can name every family member who has ever had a disease, the causes of the disease and how it was or was not treated by physicians. The retelling of family health history has been happening for centuries and provides valuable information to the rest of the family and medical care providers about risk for those diseases.
In the medical profession, family health history is captured in a number of ways, from a series of checkboxes to detailed narrations. One of the most common ways a clinician will capture a family health history in a genetics clinic is by creating a pedigree. The pedigree is a pictorial way to capture large amounts of detailed health/medical information.
A pedigree is quite different from a typical family tree, however some of the same information can be found in both. A typical family tree consists of lines connecting names of individuals within a family and the occasional addition of some health information. Typically, family trees are made for genealogical purposes. A medical pedigree also traces individuals through a family, but does not necessarily include names and is used primarily for tracing health related information. Pedigrees include a large amount of additional information about each person's health. Pedigrees also use a standard notation and set of symbols, while family trees are not standardized and may be drawn in a number of very creative and beautiful ways.
The family health history provides important insight about an individual. It contains information about a personÃÂâÃÂÃÂÃÂÃÂs family structure, relationships and ethnicity. This can help a healthcare provider get to know a patient and understand his or her background. By including details about the health and disease status of relatives, a healthcare provider can determine traits and diseases that are prevalent in a family and identify possible risk factors. Organizing family health history information into a pedigree allows a person to view all of this information in a standardized and easily accessible form.
Biological relatives share genetic information with one another, and thus may share genetic risk factors for disease. Likewise, family members (biological and nonbiological) may also share risk factors due to similar environments and lifestyles. It may be difficult to determine whether a family history of disease is caused by shared genetic factors, environmental factors, or both.
Having a family history of a particular disease may increase a personÃÂâÃÂÃÂÃÂÃÂs disease risk. This is true for single-gene conditions like cystic fibrosis that follow predictable inheritance patterns. It is also true for common complex diseases like diabetes and heart disease, although the impact on risk is much less predictable and more difficult to estimate.
Understanding a personÃÂâÃÂÃÂÃÂÃÂs risk for future disease can help guide medical care. For many conditions, steps can be taken to help prevent or lower the risk of disease. For example, individuals with a family history of early-onset (before age 50) colon cancer, are likely at an increased risk, and should consider screening through colonoscopy earlier and more often than the general population.