Genotype-based screening for hereditary hemochromatosis: II. Attitudes toward genetic testing and psychosocial impact--a report from a German pilot study

Twenty-Five Years of Contemplating Genotype-Based Hereditary Hemochromatosis Population Screening

Hereditary hemochromatosis (HH) is a rather frequent, preventable disease because the progressive iron overload affecting many organs can be effectively reduced by phlebotomy. Even before the discovery of the major gene, HFE, in 1996, hemochromatosis was seen as a candidate for population-wide screening programmes. A US Centers of Disease Control and the National Human Genome Research Institute expert panel convened in 1997 to consider genotype-based HH population-wide screening and decided that the scientific evidence available at that time was insufficient and advised against. In spite of a large number of studies performed within the last 25 years, addressing all aspects of HH natural history, health economics, and social acceptability, no professional body worldwide has reverted this decision, and HH remains a life-threatening condition that often goes undetected at a curable stage.

Genetic explanations, discrimination and chronic illness: A qualitative study on hereditary haemochromatosis in Germany

OBJECTIVE

The objective of this study is to explore the discriminatory impacts of genetic diagnosis for people living with the chronic illness of hereditary haemochromatosis in Germany.

METHODS

Semi-structured interviews with 15 patients; all had tested positive for a genetic mutation associated with haemochromatosis and already displayed symptoms of the disease. Inductive approach, with interviews collaboratively interpreted by the research group in a vertical and horizontal analysis informed by a multi-person perspective.

RESULTS

First, as the genetic diagnosis of the disease holds the promise of therapeutic intervention, the interviewees perceived it as leading to relief. Second, the interviewees felt stigmatized by their family members, they complained of social isolation and a lack of acknowledgement of their health problems. Third, they feared disadvantages for themselves or their children at their place of work, when buying insurance coverage, and when attempting to donate blood.

DISCUSSION

The findings point to the need for an expanded view on genetic discrimination. Besides institutional discrimination, it appears necessary to systematically address interactional stigmatization and take anxieties and fears into account. Here we see starting points for providing essential support through specialist and self-help groups to those faced with the genetic diagnosis of haemochromatosis in addition to and beyond the legal protection against genetic discrimination that already exists.

To tell or not to tell - what to do about p.C282Y heterozygotes identified by HFE screening

Hereditary hemochromatosis (HH) is a common preventable disorder of iron overload that can result in liver cirrhosis and reduced lifespan. Most HH is due to homozygosity for the HFE p.C282Y substitution. We conducted a study of screening for p.C282Y in high schools where p.C282Y heterozygotes (CY) individuals were informed of their genotype by letter. We studied whether these individuals understood the implications of their genotype, whether this resulted in anxiety or reduced health perception and whether cascade testing was higher in families of CY than wild-type homozygous (CC) individuals. We found 586 of 5757 (1 in 10) screened individuals were CY. One month after receiving their result, 83% correctly answered that they have one copy of p.C282Y. There was no adverse change in anxiety or health perception from prior to screening to 1 month after receiving results. Significantly more family members of CY individuals than CC individuals were informed about HH and had testing for HH. In conclusion, we found that informing CY individuals of their genotype does not increase anxiety and the implications are generally well understood. This leads to cascade testing in a minority of families. CY individuals should be informed of their genetic status when identified by population screening.

Genome-wide association studies and genetic risk assessment of liver diseases

Genetic tests can help clinicians to diagnose rare monogenic liver diseases. For most common liver diseases, however, multiple gene variants that have small to moderate individual phenotypic effects contribute to the overall risk of disease. An individual's level of risk depends on interactions between environmental factors and a wide range of modifier genes, which are yet to be identified systematically. The latest genome-wide association studies in large cohorts of patients with gallstones, fatty liver disease, viral hepatitis, chronic cholestatic liver diseases or drug-induced liver injury have provided new insights into the pathophysiology of these illnesses and have suggested the contribution of previously unsuspected pathogenic pathways. Studies in mouse models have identified further susceptibility genes for several complex liver diseases. As a result, in the future polygenic risk scores might help to define subgroups of patients at risk of developing liver diseases who would benefit from preventative measures and/or personalized therapy. Now that whole-genome sequencing is possible, comprehensive strategies for integrating genomic data and counseling of patients need to be developed.

Psychosocial aspects of DNA testing for hereditary hemochromatosis in at-risk individuals: a systematic review

AIM

To review the psychosocial benefits and harms of DNA testing for HFE-related hereditary hemochromatosis (HH) in at-risk individuals.

BACKGROUND

HH is a common genetic disease in people of European descent. DNA-based predisposition testing is used for diagnosis or in the context of family testing, but there are concerns about potential psychosocial consequences.

METHODS

Fifteen electronic databases (including Medline and Cochrane) were searched from inception to April 2007 to identify any quantitative or qualitative primary research that considered DNA testing of individuals considered at-risk of HH and reported psychosocial outcomes. Inclusion criteria, data extraction, and quality assessment were undertaken by standard methodology.

RESULTS

Three observational studies met the inclusion criteria of the review; each had methodological limitations. On receipt of test results, anxiety levels fell or were unchanged; general health-related quality-of-life outcomes improved in some aspects, or were unchanged with respect to pretest result values. Outcomes were not reported separately for those referred for diagnosis and those with family history of HH. Results suggest that genetic testing for HH in at-risk individuals is accompanied by few negative psychosocial outcomes.

CONCLUSION

The evidence on the psychosocial aspects of DNA testing for HH in at-risk individuals is limited. Further research might be required if other factors influencing the natural history of the disease phenotype are identified.

Screening for hemochromatosis and iron overload: satisfaction with results notification and understanding of mailed results in unaffected participants of the HEIRS study

AIM

The purpose of this study was to assess the level of satisfaction and understanding of test results, by a sample of non-C282Y homozygous participants in the hemochromatosis and iron overload screening (HEIRS) study, who received serum ferritin (SF), transferrin saturation (TS), and HFE gene test results by mail.

METHODS

Approximately 1 month after receiving test results by mail, participants were surveyed about understanding of and satisfaction with results notification.

RESULTS

Overall, participants were satisfied with receiving test results by mail. Participants receiving results with one or two HFE mutations or TS and/or SF levels outside the normal range (an "alert value") were less likely to be satisfied with this method of notification. Participants with normal HFE test results understood their results and recommendations better than those with one or two mutations. Although all participants received results letters in their native language, English-speaking participants had higher mean understanding scores than Mandarin, Vietnamese, or Spanish-speaking participants.

CONCLUSION

Participants were satisfied with receiving test results by mail. However, the level of understanding of the results was not sufficient for this mode of results notification to stand alone, especially for non-English speaking participants, and all participants with one or more test results outside the normal range.

The Cost-Effectiveness of Screening for Hereditary Hemochromatosis in Germany: A Remodeling Study

Objective . Genetic tests for hereditary hemochromatosis (HH) are currently included in the German ambulatory care reimbursement scheme but only for symptomatic individuals and the offspring of HH patients. This study synthesizes the most current evidence to examine whether screening in the broader population is cost-effective and to identify the best choice of initial and follow-up screening tests. Methods . A probabilistic decision-analytic model was constructed to calculate cost per life year gained (LYG) for HH screening among male Caucasians aged 30. Three strategies were considered in both the general population and male offspring of HH patients: phenotypic (transferrin saturation, TS), genotypic (C282Y mutation), and sequential (genotype if TS is elevated) screening. Results . The incremental cost-effectiveness of sequential screening among male offspring, sequential population-wide screening, and genotypic screening is 41 000, 124 000, and 161 000 /LYG, respectively. All other strategies were subject to simple or extended dominance. The results are subject to high uncertainty. The most influential parameters in the deterministic one-way sensitivity analysis are discounting of life years gained and the adherence of patients to preventive phlebotomy. Discussion . The current German policy of only screening at-risk individuals is consistent with health economic decision making based on typically accepted thresholds. However, conducting the DNA test after the first elevated TS result is more cost-effective than waiting for a second TS result as recommended by the German guidelines. Further empirical work regarding adherence to long-term prevention recommendations and explicit and well-justified guidance for the choice of discount rates in German economic evaluation are needed.

Results communication and patient education after screening for possible hemochromatosis and iron overload: experience from the HEIRS Study of a large ethnically and linguistically diverse group

PURPOSE

We assessed the effectiveness of educational interventions for conveying clinical findings and information about hereditary hemochromatosis (HH) and iron overload (IO) to individuals evaluated clinically after initial screening for HH/IO with serum ferritin (SF) concentration, transferrin saturation (TS), and HFE genotyping.

METHODS

A questionnaire mailed to 2300 cases and controls 1 month after a letter summarizing clinical findings measured understanding of results and recommendations, knowledge of HH/IO, and satisfaction with information received.

RESULTS

Of 1622 (70.5%) participants completing relevant items, 83.6% were satisfied with receiving initial screening results by mail, 93.4% found information clear and easy to understand, 89.2% generally felt they got enough information, but 47.5% still had questions. C282Y/C282Y homozygosity with normal TS/SF predicted the best understanding of genetic results. Many with no mutations thought relatives were at risk. Iron levels created most confusion, and a third incorrectly recalled treatment recommendations. Having any abnormal result, lower education, older age, and being non-white, and/or non-English speaking predicted lower understanding.

CONCLUSIONS

Combining genotypic and phenotypic screening for HH/IO creates additional difficulties in communicating results-particularly to those with low health literacy. Explaining aberrant iron TS and SF levels and low-risk genotypes, follow-up recommendations, and risk to relatives will need creative, culturally appropriate strategies.

Psychosocial impact of genetic testing for hemochromatosis in the HEIRS Study: a comparison of participants recruited in Canada and in the United States

The Hemochromatosis and Iron Overload Screening (HEIRS) Study screened 101,168 participants recruited from primary-care clinics in Canada and the United States. The present study investigated differences in the psychological effects of genetic screening for hemochromatosis (HFE mutation analysis) in participants from each country. Study participants comprised a subset of 2,654 individuals who donated blood for HFE mutation analysis. The initial screening and 1-month post-result questionnaires included measures of General Health, Mental Health (SF-36), and a measure of the percentage of individuals who experienced at least one example of worry in response to the genetic testing. Participants reported similar changes in general health and mental health, regardless of mutation result, or country. Although a significantly lower percentage of Canadian participants than U.S. participants indicated at least one negative emotional response to the genetic testing, greater than 50% of C282Y homozygote participants (the gene mutation most strongly associated with hemochromatosis) from both countries experienced such in response to testing. Thus, although not serious enough to affect individuals' mental or physical health, there was evidence of at least one element of negative emotional response to the genetic testing. These findings suggest that population screening for common HFE mutations associated with hemochromatosis risk has similar psychological effects on Canadian and U.S. individuals, although fewer Canadians may experience a negative response to such testing.

Hereditary hemochromatosis screening: effect of mutation penetrance and prevalence on cost-effectiveness of testing algorithms

Screening for hereditary hemochromatosis, although largely discussed, is not yet implemented in clinical practice. We evaluated the cost-effectiveness of 165 hemochromatosis population-screening algorithms involving two or three of several screening tests by developing a computer program that simulates all possible screening scenarios. Input data comprised government estimates of health services data and costs and a virtual population with user-defined demographic characteristics (including variable HFE mutation frequencies and penetrance values). We show that when C282Y homozygote prevalence is set at 3:1000, population screening appears cost-effective when penetrance of the biochemical phenotype is >0.70. When only hepatocellular carcinoma and cirrhosis are considered as the cost-driving complications, population-based screening is not significantly more cost-efficient than no screening, but life expectancy of individuals identified with hereditary hemochromatosis and treated is still improved by 7 years. Among the 165 screening algorithms tested in 91 different virtual populations of one million individuals, biochemical tests usually perform better as the initial test than genetic testing. Indeed, the genetic testing is most cost-effective as the final confirmatory test. Finally, for most combinations of prevalence and penetrance of HFE, one screening algorithm--unbound iron-binding capacity + transferrin saturation--appeared robust enough to be always within the top 5 most cost-effective strategies.

Kommunikation genetischer Risiken aus der Sicht der humangenetischen Beratung: Erfordernisse und Probleme

Genetic counselling is the single most important instrument for the individual communication of genetic risks. Beyond medical and psychosocial purposes in terms of preparing diagnostic measures and coping with results, genetic counselling also serves as a means to ensure the clients' decision autonomy through adequately informed consent. Accordingly, indispensable preconditions of the counselling process are voluntariness, individuality, non-directiveness, and respect of the right not to know. However, the requirement that any genetic diagnosis should be embedded into genet ic counselling is all too often neglected in today's reality of medicine. Consequently, there is urgent need of legislation ensuring mandatory counselling at least before prenatal and predictive genetic testing. Additionally, clear standards must be established and enforced for the quality of the counselling process as well as for the qualification of counsellors, and sufficient personal and institutional resources must be provided.

A diagnostic approach to hemochromatosis

In the present clinical review, a diagnostic approach to hemochromatosis is discussed from the perspective of two clinicians with extensive experience in this area. The introduction of genetic testing and large-scale population screening studies have broadened our understanding of the clinical expression of disease and the utility of biochemical iron tests for the detection of disease and for the assessment of disease severity. Liver biopsy has become more of a prognostic test than a diagnostic test. The authors offer a stepwise, diagnostic algorithm based on current evidence-based data, that they regard as most cost-effective. An early diagnosis can lead to phlebotomy therapy to prevent the development of cirrhosis.