Background
Predictive genetic testing is available for a range of diseases, from single gene diseases, such as Huntington's disease and cystic fibrosis, to multi-factorial diseases, such as type 1 diabetes, hereditary cancers, and familial hypercholesterolemia.
Type 1 diabetes is a complex disease for which important genetic components have been identified. A specific combination of the HLA class II genes (HLA-DRB1*0401-DQA1*03-DQB1*0302/DRB1*03-DQA1*05-DQB1*02) will give those who carry this genotype a 20% lifetime risk for developing type 1 diabetes [
1‐
5]. In the Environmental Triggers of Type 1 Diabetes (MIDIA) study Norwegian newborns carrying this high-risk genotype were identified and followed in a quest to identify the environmental factors of the disease [
6,
7]. In the Norwegian population, 2.1% of newborns have this genotype, and this group represents approximately 34% of future cases of type 1 diabetes [
5].
Several other studies have used predictive genetic testing of newborns as a strategy to solve research questions about environmental factors contributing to type 1 diabetes, including DIPP in Finland [
8], PANDA in Florida [
9,
10], DiPiS in Sweden [
11], DAISY in Colorado [
12], and the multinational TEDDY study in the USA and Europe [
13‐
15]. The main advantage for study participants identified as high-risk individuals is the possibility of early detection of the destruction of the insulin producing cells by autoantibodies, resulting in a milder disease onset [
16], and the possibility of being the first to participate in intervention studies when possible preventive agents get available. However, there may be disadvantages of living with the knowledge of an increased susceptibility to a disease with no known prevention. Thus, even though predictive testing is highly acknowledged as a valuable research method per se, the predictive testing of children has given rise to concerned debate [
17‐
19]. In an article about ethics, Ross concluded that, if the research does not incorporate a prevention strategy, studies involving predictive genetic testing of newborns should avoid disclosing test results to minimize the harm to infants and their families [
18].
With the widespread and increasing use of genetic tests, assessing the adverse effects of information about susceptibility genes for disease on the tested subjects is important. Our study aimed to estimate the effect on maternal mental health from receiving genetic risk information about their newborns. Outcome measures were maternal self-report scores of anxiety and depression symptoms, satisfaction with life, self-esteem, and serious worry about the child. A number of previous studies [
20‐
24] have examined maternal reactions after being informed that their children have an elevated genetic risk for type 1 diabetes. None of these studies have shown a significant effect on symptoms of anxiety or other mental health disorders as a result of the testing, though a few mothers did seem to react strongly. Previous studies were conducted in a setting in which the mothers were asked questions about how they felt in connection with the genetic testing project. The present study was designed differently. When completing the questionnaire, the mothers were not aware that their answers were going to be used for any particular comparisons, though they were rightfully informed that the personal data would be used for multiple research purposes. Thus, our results were not affected by reporting bias associated with maternal attitudes towards genetic risk information or other factors motivating the mothers to under- or over-report poor mental health.
In the present study, information about mental health is reported twice: before and after the mothers received the information about genetic risk. These data permit us to answer our main research question of to what extent receiving information about a young child having an increased risk of type 1 diabetes changes maternal well-being and mental health.
Discussion
This study compared mental health measures between mothers who received genetic risk information about their child and a control group. The results show no association between maternal notification of the results from predictive genetic testing of newborns for type 1 diabetes and maternal symptoms of anxiety and depression, satisfaction with life, self-esteem, or serious worry about the child.
Our study design is strong in some respects. The participants were from the MoBa study, a national prospective pregnancy cohort in which some of the mothers also participated in genetic testing of their newborns for HLA-conferred susceptibility for type 1 diabetes as part of the MIDIA study. Unlike most studies on the effect of testing newborns for a genetic risk of type 1 diabetes [
20‐
24], the responses were given in a "neutral context": that is, the MoBa study did not have a specific purpose of studying the effects of genetic risk, so the mothers were not prompted to mentally focus on what they were supposed to report or what the researchers might expect them to report about the effects of such painful information. The study sample consisted of 166 mothers of children with the high-risk genotype and a control group of 7224 mothers of children not carrying the high-risk genotype for type 1 diabetes. These large sample sizes provide adequate power for detecting differences between the two groups of mothers. The mental health measurements were reported both before and after receiving the information about genetic risk, providing the opportunity to adjust for baseline measurements in the analysis. Finally, consistency of the findings across three different validated measures of mental health strengthens the conclusion that mental health was not reduced by communicating genetic risk.
Previous studies examining the psychological reactions of mothers of children with high genetic risk for type 1 diabetes found no significant effect on anxiety or other serious mental health symptoms in the group as a whole in response to genetic risk information [
20‐
24]. The present study confirmed the main results from previous studies. The contribution from our study is associated with an absence of context effects, large sample sizes, and available baseline scores. Weaknesses in previous studies were small sample sizes [
22,
24], lack of baseline measures [
20,
21,
23], or no control group [
20,
21]. In some previous studies, effects of genetic risk information were revealed when the mothers were asked questions relating directly to the test results [
22,
23]. One week after obtaining the risk information, 55% of the mothers surveyed by Simonen
et al. expressed modest worry about the test results [
23]. In addition, Kerruish
et al. reported higher levels of concern about the child's genetic risk status among mothers of high-risk children compared to low-risk children [
22]. Because the questions in the present study were taken from questionnaires intended to study health and well-being in general, specific questions about concern about the genetic test results were not included, and therefore cannot be compared with these previous studies.
A weakness of the present study is the time lag between exposure to the risk information and observation of mental health. The MoBa 6 month questionnaire was distributed 3 to 3.5 months after information about risk was provided. Review studies investigating the effects of predictive genetic testing on adults have indicated that, over time, risk perception decreases [
37], and test results were rarely predictive of distress more than one month after testing [
38]. On the other hand, the MIDIA follow-up package, which is an obvious reminder about the child's risk, is sent to the parents around 2 weeks before completing the 6 months questionnaire. Overall, one cannot exclude that a difference between the mothers of high-risk and non-high-risk children would have been detected if maternal psychological health had been assessed closer to the time that the risk information was provided.
The parents of high-risk and non-high-risk children received risk information and counselling to a different extent. During the period after testing, the children with type 1 diabetes were subject to follow-up, including the opportunity for the parents to consult the project physician and health nurses at any time. The follow-up also included biological monitoring of blood samples to measure autoantibody levels, thus increasing the possibility of early diagnosis and a less severe onset of the disease if the child were to develop type 1 diabetes. If the mothers of high-risk children had been left by themselves after receiving the risk information, we cannot exclude some deterioration of maternal mental health.
Information about a child's seroconvertion is expected to lead to increased anxiety in the mothers, as this is a strong indicator of increased risk for development of type 1 diabetes [
39]. However, none of the children seroconverted at the 3 months follow-up.
The findings of this study are not necessarily fully valid for genetic screening. In screening, all newborns would be enrolled for genetic testing, whereas in a prospective cohort study, participants decide, after careful consideration, if they want to participate in the study and receive the results. This may have led to self-selection of individuals who believe themselves to be fit to handle risk information. This assumption was supported in a recent study [
40], which found that adults who anticipated having adverse psychological reactions to genetic testing were less likely to choose genetic testing. Likewise, Codori
et al. compared a group who had chosen predictive testing for Huntington's disease and a group who had chosen not to be tested [
41]. The conclusion was that the tested group anticipated problems with emotional reactions less often and expected to be able to cope with such reactions should they appear. Furthermore, Decruyenaere
et al. found that the individuals who tested themselves for Huntington's disease had higher ego strength and were more socially extroverted than the general population [
42].
One of the limitations of quantitative studies such as ours is the inability to acknowledge and be fully aware of "single case destinies", small number of mothers who might react very strongly to genetic risk information about their child. Although the present study does not show an association between predictive genetic testing and maternal mental health, previous studies have shown that such information could be a burden to a few individuals [
20,
21,
23]. Hood
et al. found that although depressive symptom scores are not elevated for the group as a whole, there is considerable variety in the responses [
20]. Mothers with ethnic minority status, low education, and post-partum depression seem to be more likely to respond to risk notification with depressive symptoms. Similarly, Johnson
et al. found that ethnic minority status, low education, and not being married are associated with elevated anxiety levels [
21].
Mothers who have type 1 diabetes seemed to worry more about their child. The mothers from the group with not-high-risk children who expressed worry would be responding to something other than the gene test. The mothers could still worry about their child getting the disease, or another chronic disease.
Acknowledgements
The Norwegian Mother and Child Cohort Study is supported by the Norwegian Ministry of Health, NIH/NIEHS (grant no. N01-ES-85433), NIH/NINDS (grant no.1 UO1 NS 047537-01), and the Norwegian Research Council/FUGE (grant no. 151918/S10). The MIDIA study was funded by the Norwegian Research Council (Grants 135893/330, 155300/320, 156477/730, 166515/V50), Norwegian Diabetes Association and Children with Diabetes Foundation (Denver, CO), NewGeneris (EU Grant Food-CT-2005-016320). We thank the public health care nurses for their effort in the recruitment to the MIDIA study and to the follow-up of high-risk children, the staff at the Biobank, Norwegian Institute of Public Health for DNA extraction and genotyping.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
KKA participated in the data acquisition, performed the analyses and drafted the manuscript. KT supervised the analyses and helped to draft the manuscript. MSK participated in the data acquisition and helped to draft the manuscript. PM participated in the design, is the principal investigator for MoBa and helped to draft the manuscript. KSR conceived of the study, participated in the design, data acquisition and coordination and helped to draft the manuscript. All authors read and approved the final manuscript.