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

Health Economic Evaluations of Hemochromatosis Screening and Treatment: A Systematic Review

BACKGROUND

Hereditary hemochromatosis (HH) is an autosomal recessive disorder that leads to iron overload and multiorgan failure.

OBJECTIVES

The aim of this systematic review was to provide up-to-date evidence of all the current data on the costs and cost effectiveness of screening and treatment for HH.

METHODS

We searched PubMed, Cochrane Library, National Health Service Economic Evaluation Database (NHSEED), Cost-Effectiveness Analysis Registry (CEA Registry), Health Technology Assessment Database (HTAD), Centre for Reviews and Dissemination (CRD), and Econlit until April 2023 with no date restrictions. Articles that reported cost-utility, cost-description, cost-minimization, cost-effectiveness, or cost-benefit analyses for any kind of management (drugs, screening, etc.) were included in the study. Patients with HH, their siblings, or individuals suspected of having HH were included in the study. All screening and treatment strategies were included. Two authors assessed the quality of evidence related to screening (either phenotype or genotype screening) and treatment (phlebotomy and electrophoresis). Narrative synthesis was used to analyse the similarities and differences between the respective studies.

RESULTS

Thirty-nine papers were included in this study. The majority of the studies reported both the cost of phenotype screening, including transferrin saturation (TS), serum ferritin, and liver biopsy, and the cost of genotype screening (HFE screening, C282Y mutation). Few studies reported the cost for phlebotomy and erythrocytapheresis treatment. Data revealed that either phenotype or genotype screening were cost effective compared with no screening. Treatment studies concluded that erythrocytapheresis might be a cost-effective therapy compared with phlebotomy.

CONCLUSIONS

Economic studies on either the screening, or treatment strategy for HH patients should be performed in more countries. We suggest that cost-effectiveness studies on the role of deferasirox in HH should be carried out as an alternative therapy to phlebotomy.

Health Care Utilization and Economic Burdens of Hemochromatosis in the United States: A Population-Based Claims Study

BACKGROUND

Little is known about the health care burden of hemochromatosis in the United States, despite its increased morbidity and mortality due to associated advanced liver diseases.

OBJECTIVE

To evaluate the health care utilization and economic burdens of hemochromatosis in the United States using real-world claims data.

METHODS

We performed a case-control analysis of adult participants in the Truven Health MarketScan Commercial Claims database from 2010 to 2015. 37,092 hemochromatosis cases were matched 1:1 by demographics and comorbidities to hemochromatosis-free controls with chronic liver disease using propensity scores. Total and service-specific health care parameters were quantified for the 12 months following versus the 12 months before the first date of hemochromatosis diagnosis and over the 12 months following a randomly selected date for controls. Incremental differences in health care burdens between cases and controls were examined using Wilcoxon signed rank tests and McNemar tests for continuous and dichotomous measures, respectively. Adjusted multivariable regression analyses using generalized linear models were used to compare the health care burdens for cases with controls.

RESULTS

In comparison with the year before, the 12 months following first hemochromatosis diagnoses had a higher total number of claims per patient (34.37 vs. 29.99; P < 0.0001) and an increase in the per-patient total health care costs ($20,023 vs. $16,905; P < 0.0001). After hemochromatosis diagnosis, health care costs were 2%, 8%, 23%, and 43% higher for inpatient admissions, emergency department visits, outpatient visits, and pharmaceutical prescriptions, compared respectively with the 12 months before diagnosis. In the 12 months following the index date, hemochromatosis cases incurred $2,732 more in total unadjusted costs compared with controls. Compared with controls, cases had adjusted incident rate ratio (IRR) 1.26 (95% CI = 1.30-1.77) times the total number of claims (IRR = 1.40, 95% CI = 1.38-1.43) more outpatient visits and IRR = 1.10 (95% CI = 1.08-1.11) excess pharmaceutical claims. Compared with controls, cases had significantly higher adjusted mean health care costs for inpatient services ($6,484 vs. $7,854), outpatient services ($7,032 vs. $11,005), and pharmaceutical claims ($2,520 vs. $2,822; all P values < 0.05). The annual health care costs among type 2 diabetes, hypertension, arthritis, and chronic kidney disease (CKD) patients with hemochromatosis were $6,968, $7,424, $2,967, and $43,847, respectively, higher than type 2 diabetes, hypertension, arthritis, and CKD patients without hemochromatosis (P < 0.0001).

CONCLUSIONS

Hemochromatosis in the United States is associated with significant health care utilization and economic burdens driven by outpatient visits, pharmaceutical claims, and a high number of comorbidities DISCLOSURES: No outside funding supported this study. The authors have no relevant financial or other relationships to disclose. An abstract containing some of the results from this study was accepted for the American Association for the Study of Liver Diseases Meeting; November 9-13, 2018; San Francisco, CA.

Cost-Effectiveness of Different Population Screening Strategies for Hereditary Haemochromatosis in Australia

INTRODUCTION

Amongst populations of northern European ancestry, HFE-associated haemochromatosis is a common genetic disorder characterised by iron overload. In the absence of treatment, excess iron is stored in parenchymal tissues, causing morbidity and mortality. Population screening programmes may increase early diagnosis and reduce associated disease. No contemporary health economic evaluation has been published for Australia. The objective of this study was to identify cost-effective screening strategies for haemochromatosis in the Australian setting.

METHODS

A Markov model using probabilistic decision analysis was developed comparing four adult screening strategies: the status quo (cascade and incidental screening), genotyping with blood and buccal samples and transferrin saturation followed by genotyping (TfS). Target populations were males (30 years) and females (45 years) of northern European ancestry. Cost-effectiveness was estimated from the government perspective over a lifetime horizon.

RESULTS

All strategies for males were cost-effective compared to the status quo. The incremental costs (standard deviation) associated with genotyping (blood) were AUD7 (56), TfS AUD15 (45) and genotyping (buccal) AUD63 (56), producing ICERs of AUD1673, 4103 and 15,233/quality-adjusted life-year (QALY) gained, respectively. For females, only the TfS strategy was cost-effective, producing an ICER of AUD10,195/QALY gained. Approximately 3% of C282Y homozygotes were estimated to be identified with the status quo approach, compared with 40% with the proposed screening strategies.

CONCLUSION

This model estimated that genotyping and TfS strategies are likely to be more cost-effective screening strategies than the status quo.

Population Screening for Hereditary Haemochromatosis in Australia: Construction and Validation of a State-Transition Cost-Effectiveness Model

INTRODUCTION

HFE-associated haemochromatosis, the most common monogenic disorder amongst populations of northern European ancestry, is characterised by iron overload. Excess iron is stored in parenchymal tissues, leading to morbidity and mortality. Population screening programmes are likely to improve early diagnosis, thereby decreasing associated disease. Our aim was to develop and validate a health economics model of screening using utilities and costs from a haemochromatosis cohort.

METHODS

A state-transition model was developed with Markov states based on disease severity. Australian males (aged 30 years) and females (aged 45 years) of northern European ancestry were the target populations. The screening strategy was the status quo approach in Australia; the model was run over a lifetime horizon. Costs were estimated from the government perspective and reported in 2015 Australian dollars ($A); costs and quality-adjusted life-years (QALYs) were discounted at 5% annually. Model validity was assessed using goodness-of-fit analyses. Second-order Monte-Carlo simulation was used to account for uncertainty in multiple parameters.

RESULTS

For validity, the model reproduced mortality, life expectancy (LE) and prevalence rates in line with published data. LE for C282Y homozygote males and females were 49.9 and 40.2 years, respectively, slightly lower than population rates. Mean (95% confidence interval) QALYS were 15.7 (7.7-23.7) for males and 14.4 (6.7-22.1) for females. Mean discounted lifetime costs for C282Y homozygotes were $A22,737 (3670-85,793) for males and $A13,840 (1335-67,377) for females. Sensitivity analyses revealed discount rates and prevalence had the greatest impacts on outcomes.

CONCLUSION

We have developed a transparent, validated health economics model of C282Y homozygote haemochromatosis. The model will be useful to decision makers to identify cost-effective screening strategies.

Costs associated with hereditary haemochromatosis in Australia: a cost-of-illness study

Objective The aim of the present study was to assess health sector, other sector and time-related (productivity) costs associated with hereditary haemochromatosis from societal, government and patient perspectives for the Australian setting. Methods A national web-based survey of people with haemochromatosis was conducted between November 2013 and February 2015. Participants completed a health survey and resource use diaries. Costs were calculated using a bottom-up approach and calculated in 2015 Australian dollars. Results Cost data were available for 157 participants. From a societal perspective, the estimated annual cost of haemochromatosis was A$274 million. The mean (95% confidence interval) cost for symptomatic patients was almost threefold greater than that of asymptomatic patients (A$10030 (7705–12670) vs A$3701 (2423–5296) respectively). Health sector and productivity-related time loss were the main cost drivers. When extrapolating costs to the Australian population level, asymptomatic haemochromatosis accounted for higher costs than symptomatic haemochromatosis (A$183 million vs A$91 million), reflecting the low clinical penetrance estimate used. Total costs increased when higher clinical penetrance estimates were used. Conclusion The present cost-of-illness study, the first to be published for haemochromatosis, found that although costs were substantial, they could be decreased by reducing clinical penetrance. Development of cost-effective strategies to increase early diagnosis is likely to result in better health outcomes for patients and lower total costs. What is known about the topic? To date, no cost-of-illness study has been conducted for haemochromatosis. Previous economic work in this area has relied on cost estimates based on expert opinion. What does the paper add? This paper provides the first cost estimates for haemochromatosis for the Australian population. These estimates, calculated using a bottom-up approach, were extrapolated to the population level based on the most robust epidemiological estimates available for the Australian population. What are the implications for practitioners? Population screening programs have been widely suggested as an approach to reduce clinical penetrance; however, the lack of high-quality economic analyses has been cited as a barrier to implementation. The present study provides the most robust cost estimates to date, which may be used to populate economic models. In addition, the present study illustrates that reducing clinical penetrance of haemochromatosis is likely to result in substantial reductions in cost.

Using iron studies to predict HFE mutations in New Zealand: implications for laboratory testing

BACKGROUND

The diagnosis of hereditary haemochromatosis (HH) is not straightforward because symptoms are often absent or non-specific. Biochemical markers of iron-overloading may be affected by other conditions.

AIM

To measure the correlation between iron studies and HFE genotype to inform evidence-based recommendations for laboratory testing in New Zealand.

METHODS

Results from 2388 patients genotyped for C282Y, H63D and S65C in Wellington, New Zealand from 2007 to 2013 were compared with their biochemical phenotype as quantified by serum ferritin (SF), transferrin saturation (TS), serum iron (SI) and serum transferrin (ST). The predictive power of these markers was evaluated by receiver operator characteristic (ROC) curve analysis, and if a statistically significant association for a variable was seen, sensitivity, specificity and predictive values were calculated.

RESULTS

Test ordering patterns showed that 62% of HFE genotyping tests were ordered because of an elevated SF alone and only 11% of these had a C-reactive protein test to rule out an acute phase reaction. The association between SF and significant HFE genotypes SF was low. However, TS values ≥45% predicted HH mutations with the highest sensitivity and specificity. A SF of >1000 µg/L was found in one at-risk patient (C282Y homozygote) who had a TS <45%.

CONCLUSION

Our analysis highlights the need for clear guidelines for investigation of hyperferritinaemia and HH in New Zealand. Using our findings, we developed an evidence-based laboratory testing algorithm based on a TS ≥45%, a SF ≥1000 µg/L and/or a family history of HH which identified all C282Y homozygotes in this study.

Quality of life utility values for hereditary haemochromatosis in Australia

Background

Hereditary hemochromatosis (HH) is a common autosomal recessive disorder amongst persons of northern European heritage. If untreated, iron accumulates in parenchymal tissues causing morbidity and mortality. As diagnosis often follows irreversible organ damage, screening programs have been suggested to increase early diagnosis. A lack of economic evidence has been cited as a barrier to establishing such a program. Previous analyses used poorly estimated utility values. This study sought to measure utilities directly from people with HH in Australia.

Methods

Volunteers with HH were recruited to complete a web-based survey. Utility was assessed using the Assessment of Quality of Life 4D (AQOL-4D) instrument. Severity of HH was graded into four categories. Multivariable regression analysis was performed to identify parameters associated with HSUV.

Results

Between November 2013 and November 2014, 221 people completed the survey. Increasing severity of HH was negatively associated with utility. Mean (standard deviation) utilities were 0.76 (0.21), 0.81 (0.18), 0.60 (0.27), and 0.50 (0.27) for categories 1–4 HH respectively. Lower mean utility was found for symptomatic participants (categories 3 and 4) compared with asymptomatic participants (0.583 v. 0.796). Self-reported HH-related symptoms were negatively associated with HSUV (r = −0.685).

Conclusions

Symptomatic stages of HH and presence of multiple self-reported symptoms were associated with decreasing utility. Previous economic analyses have used higher utilities which likely resulted in underestimates of the cost effectiveness of HH interventions. The utilities reported in this paper are the most robust available, and will contribute to improving the validity of future economic models for HH.

A Systematic Review and Narrative Synthesis of Health Economic Studies Conducted for Hereditary Haemochromatosis

BACKGROUND

Hereditary haemochromatosis (HH) is a common genetic condition amongst people of northern European heritage. HH is associated with increased iron absorption leading to parenchymal organ damage and multiple arthropathies. Early diagnosis and treatment prevents complications. Population screening may increase early diagnosis, but no programmes have been introduced internationally: a paucity of health economic data is often cited as a barrier.

OBJECTIVE

To conduct a systematic review of all health economic studies in HH.

METHODS

Studies were identified through electronic searching of economic/biomedical databases. Any study on HH with original economic component was included. Study quality was formally assessed. Health economic data were extracted and analysed through narrative synthesis.

RESULTS

Thirty-eight studies met the inclusion criteria. The majority of papers reported on costs or cost effectiveness of screening programmes. Whilst most concluded screening was cost effective compared with no screening, methodological flaws limit the quality of these findings. Assumptions regarding clinical penetrance, effectiveness of screening, health-state utility values (HSUVs), exclusion of early symptomatology (such as fatigue, lethargy and multiple arthropathies) and quantification of costs associated with HH were identified as key limitations. Treatment studies concluded therapeutic venepuncture was the most cost-effective intervention.

CONCLUSIONS

There is a paucity of high-quality health economic studies relating to HH. The development of a comprehensive HH cost-effectiveness model utilising HSUVs is required to determine whether screening is worthwhile.

An economic evaluation: Simulation of the cost-effectiveness and cost-utility of universal prevention strategies against osteoporosis-related fractures

A patient-level Markov decision model was used to simulate a virtual cohort of 500,000 women 40 years old and over, in relation to osteoporosis-related hip, clinical vertebral, and wrist bone fractures events. Sixteen different screening options of three main scenario groups were compared: (1) the status quo (no specific national prevention program); (2) a universal primary prevention program; and (3) a universal screening and treatment program based on the 10-year absolute risk of fracture. The outcomes measured were total directs costs from the perspective of the public health care system, number of fractures, and quality-adjusted life-years (QALYs). Results show that an option consisting of a program promoting physical activity and treatment if a fracture occurs is the most cost-effective (CE) (cost/fracture averted) alternative and also the only cost saving one, especially for women 40 to 64 years old. In women who are 65 years and over, bone mineral density (BMD)-based screening and treatment based on the 10-year absolute fracture risk calculated using a Canadian Association of Radiologists and Osteoporosis Canada (CAROC) tool is the best next alternative. In terms of cost-utility (CU), results were similar. For women less than 65 years old, a program promoting physical activity emerged as cost-saving but BMD-based screening with pharmacological treatment also emerged as an interesting alternative. In conclusion, a program promoting physical activity is the most CE and CU option for women 40 to 64 years old. BMD screening and pharmacological treatment might be considered a reasonable alternative for women 65 years old and over because at a healthcare capacity of $50,000 Canadian dollars ($CAD) for each additional fracture averted or for one QALY gained its probabilities of cost-effectiveness compared to the program promoting physical activity are 63% and 75%, respectively, which could be considered socially acceptable. Consideration of the indirect costs could change these findings.

[Using value of information analysis in decision making about applied research. The case of genetic screening for hemochromatosis in Germany]

Public decision makers face demands to invest in applied research in order to accelerate the adoption of new genetic tests. However, such an investment is profitable only if the results gained from further investigations have a significant impact on health care practice. An upper limit for the value of additional information aimed at improving the basis for reimbursement decisions is given by the expected value of perfect information (EVPI). This study illustrates the significance of the concept of EVPI on the basis of a probabilistic cost-effectiveness model of screening for hereditary hemochromatosis among German men. In the present example, population-based screening can barely be recommended at threshold values of 50,000 or 100,000 Euro per life year gained and also the value of additional research which might cause this decision to be overturned is small: At the mentioned threshold values, the EVPI in the German public health care system was ca. 500,000 and 2,200,000 Euro, respectively. An analysis of EVPI by individual parameters or groups of parameters shows that additional research about adherence to preventive phlebotomy could potentially provide the highest benefit. The potential value of further research also depends on methodological assumptions regarding the decision maker's time horizon as well as on scenarios with an impact on the number of affected patients and the cost-effectiveness of screening.

Screening for hereditary haemochromatosis

Hereditary haemochromatosis (HH) is a common autosomal recessive disorder of iron overload in Caucasian populations. Clinical manifestations usually occur in individuals homozygous for the C282Y mutation in the HFE gene product and who have developed significant iron loading. Current screening methods can detect affected individuals either prior to or early during disease evolution, enabling early introduction of phlebotomy treatment that can normalise life expectancy. Evaluation of possible iron overload, via measurement of serum transferrin saturation and ferritin level, is the most appropriate initial test for those subjects presenting clinically for evaluation. HFE genotyping, when combined with serum biochemical measurements, defines the presence of likely iron overload and the underlying genetic disorder and is the preferred initial screening modality for families of an affected individual. Definitive proof of iron overload requires measurement of hepatic iron concentration or total iron burden via therapeutic phlebotomy; elevated serum ferritin level alone is not adequate. We now recognise that the natural history of HH is not as discrete as previously believed, because genetic and environmental modifiers of disease penetrance are increasingly identified as influencing the clinical expression of HH. In fact, a minority of C282Y homozygotes develop classical 'iron overload disease', although it has recently emerged that the disorder may predispose to breast and colorectal cancer. Uncertainties as to the true clinical impact of the condition at a population level lead to current recommendations of cascade screening of families of affected patients, case-finding in high-risk groups, such as patients with clinical manifestations consistent with the diagnosis, and a high level of clinical awareness in the community to facilitate early diagnosis. Generalised population screening is not presently recommended.

Mass spectrometry measurement of plasma hepcidin for the prediction of iron overload

BACKGROUND

Hepcidin has emerged as the primary regulator of iron homeostasis. Previous studies on assessing urinary hepcidin are limited. We developed a method for quantifying hepcidin-25 (Hep-25) in plasma using surface-enhanced laser-desorption-ionization time-of-flight mass spectrometry (SELDI-TOF/MS) and a 25-AA peptide as reference standard. The aims of the study were 1) to assess the performance of this method in different conditions of iron metabolism disorders; 2) to assess the diagnostic validity of non-invasive serum biomarkers in the identification of iron overload.

METHODS

Validation of the method was performed in 10 patients with type I hemochromatosis (HE) and in 177 subjects previously enrolled in a general population epidemiological study. Among the latter group, 17 had non-alcoholic fatty liver disease, 10 had chronic hepatitis C, and 150 subjects had normal ultrasound, normal liver function tests (LFTs), an alcohol intake < 20 g ethanol/day and were negative for the C282Y mutation. The following biomarkers were assayed in each case: plasma Hep-25, C282Y and H63D mutations of the HFE gene; serum iron, ferritin (SF), transferrin saturation, transaminases, γ-glutamyltransferase (GGT), glucose, insulin, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol and triglycerides.

RESULTS

Plasma Hep-25 concentrations were higher in HCV+ patients (26.3 ± 7.2 nmol/L) than in controls, and correlated positively with SF (p < 0.001). H63D heterozygous subjects revealed a pattern of iron overload that was significantly higher than H63D wild type subjects. Analyzing the data with the Biomarker Pattern 5.0.2. software to identify the most significant biomarkers for discriminating between HE cases and controls allowed us to produce an algorithm with four terminal nodes, which included glucose > 4.8 mmol/L and Hep-25/SF ratio ≤ 6.6 as the main splitters. These variables enabled the correct diagnosis of HE with 100% sensitivity, 93% specificity and an area under the receiver operating characteristic (ROC) curve of 0.993.

CONCLUSIONS

Our plasma Hep-25 mass spectrometry method yields measurements that reflect pathological and genetic influences; simple non-invasive biomarkers (Hep-25/SF ratio and glucose) can predict the presence of HE.

Impact of gene patents and licensing practices on access to genetic testing for hereditary hemochromatosis

Hereditary hemochromatosis is an iron metabolism disorder that leads to excess iron buildup, especially in the heart, liver, and pancreas. Mutations in the HFE gene are the single most common cause of hereditary hemochromatosis, which can be treated effectively if diagnosed early. Patents cover the HFE gene, related proteins, screening methods, and testing kits. Most initial testing for hereditary hemochromatosis is biochemical, but HFE deoxyribonucleic acid testing or genotyping is used to confirm a diagnosis of inherited hemochromatosis. Concerns over patents covering HFE testing emerged in 2002, when scholars argued that exclusive licensing and the patent-enabled sole provider model then in place led to high prices and limited access. Critics of the sole provider model noted that the test was available at multiple laboratories before the enforcement of patents. By 2007, however, Bio-Rad Limited, acquired the key intellectual property and sublicensed it widely. In part because of broad, nonexclusive licensing, there are now multiple providers and testing technologies, and research continues. This case study illustrates how both changes in intellectual property ownership and evolving clinical utility of HFE genetic testing in the last decade have effected the licensing of patents and availability of genetic testing.

Cost effectiveness of pharmacogenomics: a critical and systematic review

The use of pharmacogenetic testing in clinical practice is limited thus far. A potential barrier to the widespread implementation of pharmacogenetic testing is the lack of evidence on whether testing provides good value for money. The objective of this review was to provide a systematic and critical review of economic evaluations of pharmacogenetic testing. A literature search using publically available databases was performed for articles published up to October 2009. To be included, studies had to meet the definition of being a pharmacogenomic study (defined as use of information on human genetic variation to target drug therapy) and an economic evaluation (defined as an evaluation of both costs and clinical outcomes). Articles that met these criteria were subsequently reviewed and graded using the Quality of Health Economic Studies (QHES) instrument. Lastly, the evidence for biomarker validity and utility were qualitatively assessed using expert opinion. A total of 34 articles were identified using our defined criteria. The most common disease category was thromboembolic-related diseases (26%), while the most common biomarkers were thiopurine methyltransferase and cytochrome P450 2C9 (18% each). Almost all studies were published after 2004 (91%). Two types of studies were identified: cost-effectiveness studies and cost-utility studies, with roughly half of the overall studies being cost-utility studies (53%) and a majority of these published within the last 3 years. The average quality score was 77 (range 29-99). Of the biomarkers reviewed, it was estimated that most had demonstrated clinical validity, but only two had demonstrated clinical utility. Despite a recent increase in the number of economic evaluations of pharmacogenetic applications, further studies examining the clinical validity and utility of these biomarkers are needed to support cost-effectiveness assessments.

Screening for iron overload: lessons from the hemochromatosis and iron overload screening (HEIRS) study

BACKGROUND

The HEmochromatosis and IRon Overload Screening (HEIRS) Study provided data on a racially, ethnically and geographically diverse cohort of participants in North America screened from primary care populations.

METHODS

A total of 101,168 participants were screened by testing for HFE C282Y and H63D mutations, and measuring serum ferritin concentration and transferrin saturation. In the present review, lessons from the HEIRS Study are highlighted in the context of the principles of screening for a medical disease as previously outlined by the World Health Organization.

RESULTS

Genetic testing is well accepted, with minimal risk of discrimination. Transferrin saturation has high biological variability and relatively low sensitivity to detect HFE C282Y homozygotes, which limits its role as a screening test. Symptoms attributable to HFE C282Y homozygosity are no more common in individuals identified by population screening than in control subjects.

CONCLUSIONS

Generalized population screening in a primary care population as performed in the HEIRS Study is not recommended. There may be a role for focused screening in Caucasian men, with some debate regarding genotyping followed by phenotyping, or phenotyping followed by genotyping.

Hereditary haemochromatosis

Haemochromatosis should currently refer to hereditary iron overload disorders presenting with a definite and common phenotype characterised by normal erythropoiesis, increased transferrin saturation and ferritin and primarily parenchymal iron deposition related to innate low (but normally regulated) production of the hepatic peptide hormone hepcidin. Since the discovery of the haemochromatosis gene (HFE) in 1996, several novel gene defects have been detected, explaining the mechanism and diversity of iron overload diseases. Overall, at least four main types of hereditary haemochromatosis (HH) have been identified. This review describes the systematic diagnostic and therapeutic strategy and pitfalls for patients suspected for HH and their relatives.

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.

Haemochromatosis

Since the discovery of the haemochromatosis gene (HFE; chromosome 6p21.3) associated with haemochromatosis in 1996, many studies about diverse aspects of this common genetic disorder have been done. Some patients present with cirrhosis and show high mortality, whereas many asymptomatic homozygotes for the C282Y mutation in the haemochromatosis gene identified in population screening studies, who have been followed up for many years, do not develop iron overload. Studies described the usefulness of transferrin saturation and serum ferritin tests, and the acceptability of genetic testing for haemochromatosis. Phlebotomy therapy improves hepatic fibrosis. Here, we summarise some new findings in haemochromatosis, a disorder first described in 1865.

Assessment of the prevalence of the 985A>G MCAD mutation in the French-Canadian population using allele-specific PCR

Inherited deficiency of medium-chain acyl-CoA dehydrogenase (MCAD) is a severe, sometimes fatal disorder. A single mutation in the MCAD gene, 985A>G, is involved in approximately 90% of cases. To evaluate the relevance of implementing a systematic population-based screening program in the province of Quebec using a biochemical test, we measured the prevalence of this mutation in a set of anonymous newborn samples from the Quebec City area, a region where the majority of its inhabitants are French-Canadians. An allele-specific polymerase chain reaction assay was designed and used to detect the mutation in 7143 DNA samples obtained from consecutive anonymous newborns. Pools of eight DNA samples were genotyped in parallel for the same mutation to validate this pooling strategy. The allelic frequency of the MCAD 985A>G mutation was found to be 0.71% and the carrier frequency 1:71 (95% confidence interval 1:55 to 1:98). This estimate predicts a homozygous frequency of 1:19,837. Ninety-nine heterozygous carriers and one homozygous individual were identified out of 7143 samples. There was 100% concordance between the individual and pooled analyses, and the pooling strategy reduced the total genotyping costs by approximately 70%. The carrier frequency estimated for this population is similar to other northwestern European populations and would support implementation of systematic newborn screening (such as tandem mass spectrometry screening) for this disease. Pooling DNA samples followed by genotyping appears to be cost-effective for estimating prevalence of rare mutations.