Can targeted genetic testing offer useful health information to adoptees

In 2004, the US Surgeon General launched the Family History Public Health Initiative to increase awareness and discussions regarding family health history (FHx). FHx reflects the combined influences of shared genetic, behavioral, and environmental factors in families. The collection and use of FHx have already been shown to be useful in risk assessment and preventive intervention for cardiovascular disease, osteoporosis, and cancer surveillance/chemoprevention, to name a few.1–3 Yet many segments of the population lack adequate access to the genetic component of FHx that might inform their health management. Here, we focus on adoptees, whose lack of genetic FHx normally reflects separation from biological parents as an inherent feature of adoption. However, our fundamental point is applicable to anyone who lacks access to genetic FHx information, which can occur for many reasons. Lack of genetic FHx is not inconsequential; for example, a recent Swedish study of adoptees emphasizes the importance of genetic factors over environmental factors for several cancers.4 Current genetic testing capabilities are at a stage where it is legitimate to ask, “Could targeted genetic analysis offer any potential benefit for those individuals who have no or limited access to family history, such as many adoptees?” And might the potential benefits and risks of genetic analysis differ between adoptees and those with access to their family history information? According to US Census data (2000), adoptees account for more than 2.5% of the US population (7.8 million). Worldwide, the United Nations estimates that at least 260,000 children are adopted annually, and the number of children globally who have lost both parents is more than 60 times this number.5 Although some adoptees have access to family history information (for example, through open adoption or biological relative adoption), many do not. One study found that for adoptees in general, family medical information was available for less than half of birth fathers.6 For international adoptees (currently one-quarter of adoptions),7 this problem is exacerbated not only by logistical difficulties but also by well-established problems surrounding the limitations of medical records in many countries from which international adoptions occur. For nearly two-thirds of international adoptees, no written medical records exist, even for basic things such as vaccination status.8,9 Moreover, even adoptees with access to some FHx information often lack ongoing, iterative refinement of this knowledge available to biologically related families who have regular, multi-generational interaction. Clinical actionability of FHx in practice is often seen in situations in which the pattern of disease in the family suggests the presence of a genetic disorder and indicates the need for earlier screening or other interventions. Many adoptees do not have access to this potentially lifesaving information. However, emerging genomic technologies are beginning to offer the possibility of accessing some of this medically actionable genetic information. An important point of similarity between genetic data and family history is that both have the greatest clinical impact on medical care when they serve to indicate an uncommon, but dramatic, risk such as that indicated by a strong family history of early diagnosis of breast cancer, colon cancer, or the like (knowledge of which can lead to recommendations for earlier screening or overtly preventive intervention). It is in several of these areas where the strongest gene–disease associations lie, such as for breast cancers and colorectal cancers. Although genetic analysis is unlikely to provide a replacement for family history when available, if properly targeted and interpreted, such analysis may have the potential to provide useful information regarding health risks when no information currently exists. Given an inability to realize family history–derived health benefits (i.e., a need for earlier screening or interventions) by many adoptees, it is critical to evaluate the potential of carefully considered genetic evaluation in this population.