Receipt of a formal (i.e. clinically determined and intended as definitive) diagnosis of familial hypercholesterolaemia (FH) had minimal impact on these patient's lives. The dominant response was one of continuity of both their beliefs and behaviour. Some patients did report some minor effects on their social relationships, broadly consistent with the limited prior research into the specific impact of an FH diagnosis. In addition, there was no discernible difference in impact for those whose diagnostic assessment included a genetic test compared with those whose assessment was made without genetic testing. These findings echo those from the comparison study of FH diagnosis from the perspective of health practitioners
. In that context, while practitioners appeared aware of and interested in the genetic element of FH, genetic testing did not play a major part in the diagnostic process.
These findings fit within psychological theories of self-regulation that describe the ways in which individuals are able to maintain emotional consistency whilst dealing with threats to their well-being
. Within this study, there was evidence of individuals both engaging in behaviours to reduce threats to health and also adapting cognitively to minimise the impact of the information that was presented to them. Regarding the former strategy, largely irrespective of the nature of their results, patients were found to use the results as evidence of the need to maintain healthy lifestyles, for example by engaging in physical activity and monitoring dietary intake. Regarding the latter, prior to testing patients were typically highly aware of their increased risk and of the nature of the testing process, and often had successfully predicted the outcome, allowing for relatively ready adjustment. They were commonly able to assimilate and integrate the test result, and even derive a sense of relief, again usually irrespective of the outcome of the assessment, in part due to regarding it as a means to reduce or remove ongoing uncertainty about their health.
Whilst the scope of the data collection process used in the current study was substantial, the results inevitably raise a question of the extent to which they can be generalised beyond the current context. To begin to address this, it is instructive to examine the results in the light of a series of systematic reviews which have assessed the impact of genetic test results on cognitions, emotions and behaviour. These reviews display considerable consistency in suggesting that the receipt of such results typically has little discernible impact. For example, a Cochrane Review that examined behavioural effects of DNA-based disease risk assessment
 found little evidence of any effect on risk-reducing health behaviours, running contrary to the commonly-voiced belief that such risk assessments motivate behavioural changes. A systematic review of the emotional impact of screening (including genetic screening) for disease risk
 found no evidence of enduring adverse effects on depression, anxiety, general distress or quality of life. Finally, regarding impact on patients’ cognitions, Collins and colleagues
 found no effects of personalised genetic risk information on perceived control over the risk in either the short or longer term, with fatalistic responses not seemingly being engendered. In sum, in spite of widespread beliefs amongst healthcare providers that genetic screening is likely to have systematic and potent emotional and behavioural effects
[24–26] the evidence increasingly suggests that this is unlikely to be the case.
Instead of a generalisable pattern irrespective of the degree of conferred risk, impact could be a function of the size of the conferred risk. Much of the evidence to date, including that derived from the previously described systematic reviews, has focused primarily on common complex diseases (e.g. cancers, diabetes, heart disease). For most such conditions, the penetrance of implicated gene variants is relatively low
, but if penetrance is high and thus the presence of a specific gene variant indicates a high probability of disease, then a greater impact may be expected. Importantly, however, the current study did not find evidence for this in the context of FH, which is linked to genetic variants of high penetrance, conferring cumulative risks of coronary heart disease of more than 50% by age 50 in men and at least 30% by age 60 in women
[28, 29]. An additional factor to consider is the severity of health consequences associated with any genetic result. Again, there is no evidence of such effects. For example, an aforementioned review included five studies of the emotional consequences of predictive genetic testing for Huntington’s disease, which has very serious health consequences and is not regarded as treatable (unlike FH)
 found no evidence of adverse emotional consequences in individuals found to be carriers.