Prevalence of genetic disease at the end of life:
Inherited factors contribute about 20% to mortality in the population. About 5% to 10% of common causes of mortality, such as cancer, are associated with strong individual genetic risks with implications for surviving family members.
Rationale for genetics assessment:
Current genetic tests are not fully clinically sensitive but can be very informative for breast, ovary, and colorectal cancers. It is typically most useful to begin testing with an affected family member. Once affected family members have died, opportunities for genetics assessment, or obtaining genetic material for future testing, may be lost, so DNA banking may be a viable option.
Options for genetics assessment:
Record patient and family history that may be relevant for genetic history. For example, “S-I-D-E”: Similar conditions in other family members, Inherited diagnoses described in the family, Deaths at an early age, and Extreme laboratory values. Collect these information for three generations of relatives on both the maternal and paternal sides of the family. Bank DNA for patients suspected to have a genetic condition and consider genetics consultation for the patient and/or family. This will allow future testing for the benefit of surviving family members.
Recognition of the genetic component of disease is increasing in clinical practice. Completion of the Human Genome Project has led to an acceleration of clinically available genetic tests with varying validity and utility. Despite increasing recognition of a genetic component for many diseases, current genetic testing still will not detect a familial mutation for many families, even among patients meeting clinical criteria for genetic disorders. Current genetic testing is often most informative if it begins with a family member most suspected to have a genetic disorder. This may include a patient dying from a condition suspected to have a genetic link. Genetic testing may not currently be available, and/or time may not be sufficient to facilitate genetic testing at the end of life. Recording available family history and banking DNA can be critical for the health of surviving family members.
Screening and Counseling
This section addresses two aspects of genetic screening at the end of life: (1) identifying patients who might benefit from DNA testing and/or DNA banking, and (2) talking with patients and family members about genetic screening at the end of life.
For every patient, collect past medical history information and family medical history including at minimum all first-degree (full siblings, children, parents) and second-degree (aunts/uncles, nieces/nephews, grandparents, grandchildren, half-siblings) relatives. Encourage patients to collect, store, and update their family health histories. A useful tool for family history collection is “My Family Health Portrait” (www.familyhistory.hhs.gov/fhh-web/home.action). A helpful mnemonic for family history screening is S-I-D-E:
S: Any family members with health conditions that are Similar to the patient’s condition?
I: Any family members with diagnoses of Inherited conditions?
D: Any family members who Died at an early age or were diagnosed with a disease at an earlier-than-typical age?
E: Does the patient or any family members have Extreme laboratory values that could suggest, for example, an inherited metabolic disease?
The S-I-D-E mnemonic is also a reminder to ask about both the maternal and paternal sides of the family, even for conditions that are more common or exclusive to one sex or the other, such as breast cancer or prostate cancer. Table 184-1 presents a list of specific conditions in patients and/or family members that suggest a hereditary component.
Consider DNA banking (see later) if the family history presents a known inherited condition affecting the patient, the patient has a condition that is present in two other close relatives, or the patient has one other relative with the same condition if it is rare or diagnosed at an earlier-than-typical age. DNA banking may be helpful if