Core Principles in Family History: Collection
Recognize and understand standard pedigree symbols
There are multiple ways to collect a patient’s medical history, and, once collected, there are different ways to organize and display that information. The critical elements of any documentation method for family history are that the information must:
- be accurate and easily updated;
- allow for detection and interpretation of patterns; and
- promote clear communication and correct interpretation.
The preferred way to organize and display family medical history is the pedigree. Standard pedigree nomenclature has been in use since 1995 (Bennett et al., 1995; Bennett et al., 2008). It is important that all health professionals understand the use of a pedigree in the collection of family history data.
Produce at least a three-generation family history that
- The patient or person seeking services (sometimes referred to as the consultand, or the proband if the patient has a medical condition)
- The historian, or person providing the information. This person may be the patient or someone else, such as a parent or foster-parent, spouse, or relative
- The patient and his or her first-degree relatives (children, siblings, parents), second-degree relatives (half-siblings, aunts, uncles, grandparents, nieces and nephews), and sometimes third-degree relatives (first cousins, half-aunts and half-uncles)
- Information for maternal and paternal sides of the family
- Degree of relationship, including: full or half siblings, children with same or different partner(s)
- Affected and unaffected relatives
- Date of collection (or date of update), and the name of collector (or updater)
- Legend or key in pedigrees, if symbols are used to designate disease
Elicit appropriate information for individuals represented in the family history as required for clinical indications
Comprehensive family history
Collection of a comprehensive family history is ideal, though often not practical. Healthcare providers should determine the level of detailed information to collect according to each patient and indication.
A comprehensive family history includes the following information:
- Age or year of birth (approximate ages appropriate for distant relatives or when exact ages are not known)*
- Relevant health information, including test results if applicable
- Diagnosis and age at diagnosis
- Age at death and year if known
- Cause of death
- Ancestral background for each biological grandparent
- Infertility, or no children by choice
- Pregnancy complications with gestational age noted, including miscarriages, stillbirths, ectopic pregnancies, pregnancy terminations, preterm birth, preeclampsia, and bleeding/clotting complications
- Consanguinity (blood relationship of parents, for example first cousins)
** The date of birth or full name of family members should not be recorded on the medical pedigree to protect the privacy of family members. If these data are needed to request medical records on a specific individual, it may be more appropriate to include them in the clinic note (Bennett et al., 2008).
Adapted from Bennett, 2010
Targeted family history
A targeted family history includes information about health problems in a patient’s relatives that are related to the specific condition of concern. This type of history is appropriate in a specialized clinical setting or when evaluating a patient for specific concerns. When evaluating a patient for a specific syndrome, for example, it is beneficial to ask about the presence in relatives of different features associated with that syndrome. A targeted family history is also appropriate if the general family history reveals a possible inherited condition.