An Entry for Personalized Medical Practice in Primary Care

The successful practice of personalized medicine in primary care depends upon understanding a patient’s individual disease risk and anticipating the best course of treatment with the goal of maintaining good health. A personalized disease risk assessment leads to recommendations for evidence-based interventions that can delay/prevent disease onset or reduce the severity of disease. As the sophistication of medical diagnoses develops and new interventions become available, the value of collecting and analyzing family health history (FHH) for maintaining patient wellness by determining ‘the right treatment, at the right time, for the right patient’ is more apparent than ever. FHH remains underutilized in primary care.

however, because of numerous barriers. Ironically, the introduction of genetic tests and genomic methods that identify carriers who might be vulnerable to a variety of medical conditions and diseases has simply raised the importance of collecting and utilizing FHH to guide patient management in primary care.

FHH is perhaps the most cost-effective and robust means to obtain information about a patient’s disease risk. A complete FHH includes the health information of a patient’s blood-related first (parents, siblings, children) and second degree (half-siblings, aunts, uncles, grandparents) relatives over three generations. To be optimally useable for analysis, FHH will denote both affected and unaffected family members, the age of disease onset, disease severity, any recurrences, and cause of death. Even partial FHH information can be useful.

 however, especially if two or more first or second degree relatives are affected from either the maternal or paternal side of a family, since two occurrences of a disease or condition within a lineage usually is sufficient to conclude that an elevated disease risk exists.

Family Health History: An Entry for Personalized Medical Practice in Primary Care

Generally, actual risk assessment algorithms derived from FHH information vary for different diseases, especially when other factors, such as age of onset, severity, recurrence, and environmental risk factors are known to be involved. For some diseases, FHH-based risk is described primarily for first degree relatives. In such cases, individual risk is elevated substantially if an immediate (first degree) family member is affected, and the additional risk revealed by affected second degree relatives may not be necessary for generating additional recommendations, and/or treatment interventions, though this information could be valuable if a genetic test is contemplated. 

For assessing a patient’s risk for developing diabetes mellitus, for example, having a first degree relative with type 2 diabetes significantly elevates personal risk (~2-5 fold), even without knowing exacerbating environmental risk factors and without information from more distant relatives. While specific genetic variants (any structural change in the nucleotide sequence of DNA will be referred to as a variant in this mini review) that occur commonly in the human population have been associated with a risk for type 2 diabetes, FHH remains a more robust predictor of T2D risk than the presence of predisposing genetic variants. For stroke, FHH is a well-established risk factor.

 According to one study, over 85% of strokes in persons less than 75 years old are concentrated in about 10% of all families, suggesting the risk-elevating effects of genetics and shared family environment. If one or both parents of a patient had a stroke, a patient’s risk for stroke or cardiovascular disease is significantly increased. Such information offers a simple and effective form of triage for evaluating a patient’s risk for stroke as well as possible interventions, including aggressive treatment of even modest hypertensive levels, which has been shown to reduce the risk of cardiovascular disease and stroke by one-fourth to one-third.

Several genetic associations have been tentatively made for a variety of specific types of stroke, precluding the utility of a simple genetic test for stroke risk [10]; the disease itself is heterogeneous in terms of cause and type, and these subtypes involve a variety of potential variants, none of which have been validated as predictors of stroke risk in the general population. As the relationship between specific types of stroke and predisposing genetic and environmental factors becomes more defined however, it is plausible that more precise diagnoses, preventive interventions, and treatments will be forthcoming.