Hereditary hemochromatosis: effect of excessive alcohol consumption on disease expression in patients homozygous for the C282Y mutation

Human genetic structure in Northwest France provides new insights into West European historical demography

The demographical history of France remains largely understudied despite its central role toward understanding modern population structure across Western Europe. Here, by exploring publicly available Europe-wide genotype datasets together with the genomes of 3234 present-day and six newly sequenced medieval individuals from Northern France, we found extensive fine-scale population structure across Brittany and the downstream Loire basin and increased population differentiation between the northern and southern sides of the river Loire, associated with higher proportions of steppe vs. Neolithic-related ancestry. We also found increased allele sharing between individuals from Western Brittany and those associated with the Bell Beaker complex. Our results emphasise the need for investigating local populations to better understand the distribution of rare (putatively deleterious) variants across space and the importance of common genetic legacy in understanding the sharing of disease-related alleles between Brittany and people from western Britain and Ireland.

Alcohol Use Unmasking Heterozygous Hereditary Hemochromatosis

Hereditary hemochromatosis (HH) is an autosomal recessive disorder characterized by excess iron absorption in the body following a mutation in the HFE gene. Though prolonged iron deposition has been shown to cause clinical symptoms such as hyperpigmentation, arthralgias, and liver damage, many individuals remain asymptomatic and exhibit no signs of iron overload. Here, we present a case where a 34-year-old with a history of severe alcohol use disorder presented with high iron, ferritin and transferrin saturation levels indicative of iron overload. Further testing for HFE gene mutations revealed simple heterozygote C282Y status, confirming the diagnosis of hereditary hemochromatosis. Simple heterozygotes, however, typically do not present with any symptoms of iron overload. This patient was counseled on lifestyle modifications which included abstaining from alcohol and reducing iron and vitamin C intake. As a result, his iron panel parameters improved. Thus, our case highlights that excessive alcohol consumption can exacerbate hereditary hemochromatosis and risk for overload even among heterozygotes.

Repositioning Drugs for Rare Diseases Based on Biological Features and Computational Approaches

Rare diseases are a group of uncommon diseases in the world population. To date, about 7000 rare diseases have been documented. However, most of them do not have a known treatment. As a result of the relatively low demand for their treatments caused by their scarce prevalence, the pharmaceutical industry has not sufficiently encouraged the research to develop drugs to treat them. This work aims to analyse potential drug-repositioning strategies for this kind of disease. Drug repositioning seeks to find new uses for existing drugs. In this context, it seeks to discover if rare diseases could be treated with medicines previously indicated to heal other diseases. Our approaches tackle the problem by employing computational methods that calculate similarities between rare and non-rare diseases, considering biological features such as genes, proteins, and symptoms. Drug candidates for repositioning will be checked against clinical trials found in the scientific literature. In this study, 13 different rare diseases have been selected for which potential drugs could be repositioned. By verifying these drugs in the scientific literature, successful cases were found for 75% of the rare diseases studied. The genetic associations and phenotypical features of the rare diseases were examined. In addition, the verified drugs were classified according to the anatomical therapeutic chemical (ATC) code to highlight the types with a higher predisposition to be repositioned. These promising results open the door for further research in this field of study.

Elevated transferrin saturation in individuals with alcohol use disorder: Association with HFE polymorphism and alcohol withdrawal severity

Iron loading has been consistently reported in those with alcohol use disorder (AUD), but its effect on the clinical course of the disease is not yet fully understood. Here, we conducted a cohort study to examine whether peripheral iron measures, genetic variation in HFE rs1799945 and their interaction differed between 594 inpatient participants with alcohol use disorder (AUD) undergoing detoxification and 472 healthy controls (HC). We also assessed whether HFE rs1799945 was associated with elevated peripheral iron and can serve as a predictor of withdrawal severity. AUD patients showed significantly higher serum transferrin saturation than HC. Within the AUD group, transferrin saturation significantly predicted withdrawal symptoms (CIWA-Ar) and cumulative dose of benzodiazepine treatment during the first week of detoxification, which is an indicator of withdrawal severity. HFE rs1799945 minor allele carriers showed elevated transferrin saturation compared to non-carriers, both in AUD and healthy controls. Exploratory analyses indicated that, within the AUD cohort, HFE rs1799945 predicted CIWA withdrawal scores, and this relationship was significantly mediated by transferrin saturation. We provide evidence that serum transferrin saturation predicts alcohol withdrawal severity in AUD. Moreover, our findings replicated previous studies on elevated serum transferrin saturation in AUD and an involvement of HFE rs1799945 in serum transferrin saturation levels in both AUD and healthy controls. Future studies may use transferrin saturation measures as predictors for treatment or potentially treat iron overload to ameliorate withdrawal symptoms.

Iron and iron-related proteins in alcohol consumers: cellular and clinical aspects

Alcohol-associated liver disease (ALD) is one of the most common chronic liver diseases. Its pathological spectrum includes the overlapping stages of hepatic steatosis/steatohepatitis that can progress to liver fibrosis and cirrhosis; both are risk factors for hepatocellular carcinoma. Moreover, ALD diagnosis and management pose several challenges. The early pathological stages are reversible by alcohol abstinence, but these early stages are often asymptomatic, and currently, there is no specific laboratory biomarker or diagnostic test that can confirm ALD etiology. Alcohol consumers frequently show dysregulation of iron and iron-related proteins. Examination of iron-related parameters in this group may aid in early disease diagnosis and better prognosis and management. For this, a coherent overview of the status of iron and iron-related proteins in alcohol consumers is essential. Therefore, here, we collated and reviewed the alcohol-induced alterations in iron and iron-related proteins. Reported observations include unaltered, increased, or decreased levels of hemoglobin and serum iron, increments in intestinal iron absorption (facilitated via upregulations of duodenal divalent metal transporter-1 and ferroportin), serum ferritin and carbohydrate-deficient transferrin, decrements in serum hepcidin, decreased or unaltered levels of transferrin, increased or unaltered levels of transferrin saturation, and unaltered levels of soluble transferrin receptor. Laboratory values of iron and iron-related proteins in alcohol consumers are provided for reference. The causes and mechanisms underlying these alcohol-induced alterations in iron parameters and anemia in ALD are explained. Notably, alcohol consumption by hemochromatosis (iron overload) patients worsens disease severity due to the synergistic effects of excess iron and alcohol.

Managing Genetic Hemochromatosis: An Overview of Dietary Measures, Which May Reduce Intestinal Iron Absorption in Persons With Iron Overload

Genetic hemochromatosis causes iron overload by excess absorption of dietary iron, due to a decreased expression of hepcidin. The objective was to elaborate dietary recommendations that can reduce intestinal iron absorption in hemochromatosis patients, based on our present knowledge of the iron contained in nutrients and the mechanisms of iron uptake. This is a narrative review. Literature search in PubMed and Google Scholar of papers dealing with iron absorption from the diet was conducted. Most important proposed dietary recommendations are: 1) Choose a varied vegetarian, semi-vegetarian or flexitarian diet. A “veggie-lacto-ovo-poultry-pescetarian” diet seems optimal. Avoid iron enriched foods and iron supplements. 2) Eat many vegetables and fruits, at least 600 g per day. Choose protein rich pulses and legumes (e.g., kidney- and soya beans). Fresh fruits should be eaten between meals. 3) Abstain from red meat from mammals and choose the lean, white meat from poultry. Avoid processed meat, offal and blood containing foods. Eat no more than 200 g meat from poultry per week. Choose fish, eggs, vegetables and protein rich legumes the other days. Eat fish two to four times a week as main course, 350 - 500 g fish per week, of which half should be fat fish. 4) Choose whole grain products in cereals and bread. Avoid iron enriched grains. Choose non-sourdough, yeast-fermented bread with at least 50% whole grain. 5) Choose vegetable oils, and low-fat dairy products. 6) Eat less sugar and salt. Choose whole foods and foods with minimal processing and none or little added sugar or salt. 7) Quench your thirst in water. Drink green- or black tea, coffee, or low-fat milk with the meals, alternatively water or non-alcoholic beer. Fruit juices must be consumed between meals. Abstain from alcoholic beverages. Drink soft drinks, non-alcoholic beer, or non-alcoholic wine instead. These advices are close to the official Danish dietary recommendations in 2021. In the management of hemochromatosis, dietary modifications that lower iron intake and decrease iron bioavailability may provide additional measures to reduce iron uptake from the foods and reduce the number of phlebotomies. However, there is a need for large, prospective, randomized studies that specifically evaluate the effect of dietary interventions.

Revisiting hemochromatosis: genetic vs. phenotypic manifestations

Iron overload disorders represent an important class of human diseases. Of the primary iron overload conditions, by far the most common and best studied is HFE-related hemochromatosis, which results from homozygosity for a mutation leading to the C282Y substitution in the HFE protein. This disease is characterized by reduced expression of the iron-regulatory hormone hepcidin, leading to increased dietary iron absorption and iron deposition in multiple tissues including the liver, pancreas, joints, heart and pituitary. The phenotype of HFE-related hemochromatosis is quite variable, with some individuals showing little or no evidence of increased body iron, yet others showing severe iron loading, tissue damage and clinical sequelae. The majority of genetically predisposed individuals show at least some evidence of iron loading (increased transferrin saturation and serum ferritin), but a minority show clinical symptoms and severe consequences are rare. Thus, the disorder has a high biochemical penetrance, but a low clinical prevalence. Nevertheless, it is such a common condition in Caucasian populations (1:100–200) that it remains an important clinical entity. The phenotypic variability can largely be explained by a range of environmental, genetic and physiological factors. Men are far more likely to manifest significant disease than women, with the latter losing iron through menstrual blood loss and childbirth. Other forms of blood loss, immune system influences, the amount of bioavailable iron in the diet and lifestyle factors such as high alcohol intake can also contribute to iron loading and disease expression. Polymorphisms in a range of genes have been linked to variations in body iron levels, both in the general population and in hemochromatosis. Some of the genes identified play well known roles in iron homeostasis, yet others are novel. Other factors, including both co-morbidities and genetic polymorphisms, do not affect iron levels per se, but determine the propensity for tissue pathology.

The effect of food and nutrients on iron overload: what do we know so far?

There has been no established food and nutrition guidance for diseases characterized by the presence of iron overload (IOL) yet. Hepcidin is a hormone that diminishes iron bioavailability. Its levels increase in response to increased iron stores. Hence, IOL conditions could hypothetically trigger a self-regulatory mechanism for the reduction of the intestinal absorption of iron. In addition, some food substances may modulate intestinal iron absorption and may be useful in the dietary management of patients with IOL. This scoping review aimed to systematize studies that support dietary prescriptions for IOL patients. It was carried out according to the method proposed by the Joanna Briggs Institute and the preferred reporting items for systematic reviews and meta-analyses (PRISMA). Although the need to restrict iron in the diet of individuals with hemochromatosis is quite clear, there is a consensus that IOL diminishes the rate of iron absorption. Reduced iron absorption is also present and has been reported in some diseases with transfusion IOL, in which serum hepcidin is usually high. The consumption of polyphenols and 6-shogaol seems to reduce iron absorption or serum ferritin concentration, while procyanidins do not cause any changes. Vitamin C deficiency is often found in IOL patients. However, vitamin C supplementation and alcohol consumption should be avoided not only because they increase iron absorption, but also because they provoke toxic oxidative reactions when the iron is excessive. Dietary approaches must consider the differences in the pathophysiology and treatment of IOL diseases.

A Review of Nutrients and Compounds, Which Promote or Inhibit Intestinal Iron Absorption: Making a Platform for Dietary Measures That Can Reduce Iron Uptake in Patients with Genetic Haemochromatosis

OBJECTIVE

To provide an overview of nutrients and compounds, which influence human intestinal iron absorption, thereby making a platform for elaboration of dietary recommendations that can reduce iron uptake in patients with genetic haemochromatosis.

DESIGN

Review. Setting. A literature search in PubMed and Google Scholar of papers dealing with iron absorption.

RESULTS

The most important promoters of iron absorption in foods are ascorbic acid, lactic acid (produced by fermentation), meat factors in animal meat, the presence of heme iron, and alcohol which stimulate iron uptake by inhibition of hepcidin expression. The most important inhibitors of iron uptake are phytic acid/phytates, polyphenols/tannins, proteins from soya beans, milk, eggs, and calcium. Oxalic acid/oxalate does not seem to influence iron uptake. Turmeric/curcumin may stimulate iron uptake through a decrease in hepcidin expression and inhibit uptake by complex formation with iron, but the net effect has not been clarified.

CONCLUSIONS

In haemochromatosis, iron absorption is enhanced due to a decreased expression of hepcidin. Dietary modifications that lower iron intake and decrease iron bioavailability may provide additional measures to reduce iron uptake from the foods. This could stimulate the patients' active cooperation in the treatment of their disorder and reduce the number of phlebotomies.

From Environment to Genome and Back: A Lesson from HFE Mutations

The environment and the human genome are closely entangled and many genetic variations that occur in human populations are the result of adaptive selection to ancestral environmental (mainly dietary) conditions. However, the selected mutations may become maladaptive when environmental conditions change, thus becoming candidates for diseases. Hereditary hemochromatosis (HH) is a potentially lethal disease leading to iron accumulation mostly due to mutations in the HFE gene. Indeed, homozygosity for the C282Y HFE mutation is associated with the primary iron overload phenotype. However, both penetrance of the C282Y variant and the clinical manifestation of the disease are extremely variable, suggesting that other genetic, epigenetic and environmental factors play a role in the development of HH, as well as, and in its progression to end-stage liver diseases. Alcohol consumption and dietary habits may impact on the phenotypic expression of HFE-related hemochromatosis. Indeed, dietary components and bioactive molecules can affect iron status both directly by modulating its absorption during digestion and indirectly by the epigenetic modification of genes involved in its uptake, storage and recycling. Thus, the premise of this review is to discuss how environmental pressures led to the selection of HFE mutations and whether nutritional and lifestyle interventions may exert beneficial effects on HH outcomes and comorbidities.

Ethanol induces skin hyperpigmentation in mice with aldehyde dehydrogenase 2 deficiency

Alcohol induces various cutaneous changes, such as palmar erythema and jaundice. However, alcohol-induced skin hyperpigmentation due to melanin deposition has not been reported. Aldehyde dehydrogenase 2 (ALDH2), one of 19 human ALDH isozymes, metabolizes endogenous and exogenous aldehydes to their respective carboxylic acids. Reduced ALDH2 greatly affects acetaldehyde metabolism, leading to its accumulation in the body after the consumption of alcohol and the consequent development of a wide range of phenotypes. In the present study, we report a novel phenotype manifesting in a mouse model with the altered expression of ALDH2. Aldh2 knockout (Aldh2+/- and Aldh2-/-) and wild-type (Aldh2+/+) mice were fed a standard solid rodent chow and a bottle of ethanol solution at concentrations of 0%, 3%, 10%, or 20% (v/v) for more than 10 weeks. The intensity of their skin pigmentation was evaluated by macroscopic observation. Ethanol-exposed Aldh2+/- and Aldh2-/- mice exhibited dose-dependent skin pigmentation in areas of hairless skin, including the soles of the paws and tail; no such changes were observed in wild-type mice. The intensity of skin pigmentation correlated with the number of Aldh2 alleles that were altered in the mice (i.e., 0, 1 and 2 for Aldh2+/+, Aldh2+/-, Aldh2-/-, respectively). Interestingly, the skin pigmentation changes reversed upon the discontinuation of ethanol. The histological examination of the pigmented skin demonstrated the presence of melanin-like deposits, mainly in the epidermis. In conclusion, we report a novel finding that the intake of ethanol induces skin hyperpigmentation in an ALDH2 activity-dependent manner.

Do pregnancies reduce iron overload in HFE hemochromatosis women? results from an observational prospective study

Background

HFE hemochromatosis is an inborn error of iron metabolism linked to a defect in the regulation of hepcidin synthesis. This autosomal recessive disease typically manifests later in women than men. Although it is commonly stated that pregnancy is, with menses, one of the factors that offsets iron accumulation in women, no epidemiological study has yet supported this hypothesis. The aim of our study was to evaluate the influence of pregnancy on expression of the predominant HFE p.[Cys282Tyr];[Cys282Tyr] genotype.

Methods

One hundred and forty p.Cys282Tyr homozygous women enrolled in a phlebotomy program between 2004 and 2011 at a blood centre in western Brittany (France) were included in the study. After checking whether the disease expression was delayed in women than in men in our study, the association between pregnancy and iron overload was assessed using multivariable regression analysis.

Results

Our study confirms that women with HFE hemochromatosis were diagnosed later than men cared for during the same period (52.6 vs. 47.4 y., P < 0.001). Compared to no pregnancy, having at least one pregnancy was not associated with lower iron markers. In contrast, the amount of iron removed by phlebotomies appeared significantly higher in women who had at least one pregnancy (e^β = 1.50, P = 0.047). This relationship disappeared after adjustment for confounding factors (e^β = 1.35, P = 0.088).

Conclusions

Our study shows that pregnancy status has no impact on iron markers level, and is not in favour of pregnancy being a protective factor in progressive iron accumulation. Our results are consistent with recent experimental data suggesting that the difference in disease expression observed between men and women may be explained by other factors such as hormones.

Pathogenesis, Diagnostics, and Treatment of Hereditary Haemochromatosis: A 150 Year-Long Understanding of an Iron Overload Disorder

Haemochromatosis is an iron overload disorder that can be inherited or acquired and when diagnosis is delayed, disease progression and death can occur. Iron overload was first described by the French internist Armand Trousseau in 1865 in an article on diabetes in which alterations in skin pigmentations were reported. Some years later, the German pathologist Friedrich Daniel von Recklinghausen coined the term ‘haemochromatosis’ for a metabolic disorder characterised by excess deposition of iron in the tissue. This disorder affects 1 in 200 subjects of Caucasians of Northern European descent. The systemic excess iron build-up condition quickly gained an intense clinical interest. Haemochromatosis can lead to severe pathological symptoms in multiple organs, including the liver, bones, spleen, heart, pancreas, joints, and reproductive organs. With the progress of the disease, hepatic damage predominates. Polymorphisms in several independent genes can lead to haemochromatosis. However, the most widely known haemochromatosis-associated and studied ones are genetic variants in the HFE gene, located on the short arm of human chromosome 6. Early detection and phlebotomy prior to the onset of fibrosis/cirrhosis can reduce morbidity and normalise life expectancy. Consequently, phlebotomy has been accepted for decades as a standard treatment for the reduction of iron load. Nowadays, other methods, such as erythrocytapheresis, therapeutic application of iron chelators and proton pump inhibitors, or hepcidin-targeted therapy, are discussed as alternative personalised treatments of hereditary haemochromatosis. This review focusses on the pathogenesis, diagnosis, and therapy of haemochromatosis.

Alcohol Consumption in Concomitant Liver Disease: How Much is Too Much?

Purpose of Review

High consumption of alcohol can lead to cirrhosis. The risk of a low to moderate consumption of alcohol in the setting of a concurrent liver disease is less clear. The aim of this review is to sum the evidence on the risk of adverse outcomes in patients with liver diseases other than alcoholic liver disease who consume alcohol.

Recent Findings

High alcohol consumption is strongly associated with adverse outcomes in most liver diseases. For hepatitis C, some evidence points to an increased risk for fibrosis progression also with low amounts. For non-alcoholic fatty liver disease, most studies indicate an inverse association between fibrosis and alcohol consumption, but methodological limitations reduce inference.

Summary

High alcohol consumption is associated with an increased risk of fibrosis progression and other adverse outcomes, while less is clear regarding low to moderate consumption. Obtaining high-level evidence on this topic ought to be the objective of future studies. Currently, an individual risk profile should be obtained in patients with liver disease who consume alcohol.

HFE genetic variability and risk of alcoholic liver disease: A meta-analysis

Studies examining the association of hemochromatosis (HFE) gene polymorphisms and susceptibility to alcoholic liver disease (ALD) yielded inconsistent results. Thus, we performed a metaanalysis to investigate whether the variations in HFE gene increase the risk of ALD. The studies published up to Feb. 2014 were identified by searching PubMed/MEDLINE, ISI Web of Science, EMBASE and China National Knowledge Infrastructure databases, which was complemented by screening the references of the retrieved studies. For all genotypes and alleles, the odds ratios (ORs) with 95% confidence intervals (CIs) according to the heterogeneity were pooled using fixed-effect model. Sixteen studies with 1933 cases and 9874 controls were included for this meta-analysis. C282Y/C282Y, C282Y/wild type, H63D/wild type and C282Y/H63D were found not to be associated with susceptibility to ALD, but increased risk of H63D/H63D (OR: 1.52, 95% CI: 1.05-2.22, P=0.029) was observed for ALD when compared to total control. Comparison of ALD patients with alcoholics without liver damage revealed a significant association of D allele, as well as a marginal association of H63D/wild type with ALD, while H63D/H63D was not significantly associated with ALD although increased value of OR was obtained. The presence of Y allele and other genotypes yielded insignificant findings when ALD patients were compared with alcoholics without liver damage. No evident publication bias or significant heterogeneity among studies was detected in this meta-analysis. In conclusion, our metaanalysis showed a marginal higher prevalence of H63D variant in ALD but did not support an increased risk of C282Y mutation.

How we manage patients with hereditary haemochromatosis

A number of disorders cause iron overload: some are of genetic origin, such as hereditary haemochromatosis, while others are acquired, for instance due to repeated transfusions. This article reviews the treatment options for hereditary haemochromatosis, with special attention to the use of erythrocytapheresis. In general, therapy is based on the removal of excess body iron, for which ferritin levels are used to monitor the effectiveness of treatment. For many decades phlebotomy has been widely accepted as the standard treatment. Recent publications suggest that erythrocytapheresis, as a more individualized treatment, can provide a good balance between effectiveness, tolerability and costs. Other treatments like oral chelators and proton pomp inhibitors, which are used in selected patients, create the possibility to further individualize treatment of hereditary haemochromatosis. In the future, hepcidin-targeted therapy could provide a more fundamental approach to treatment.

Haemochromatosis

Haemochromatosis is now known to be an iron-storage disease with genetic heterogeneity but with a final common metabolic pathway resulting in inappropriately low production of the hormone hepcidin. This leads to increase in intestinal absorption and deposition of excessive amounts of iron in parenchymal cells which in turn results in eventual tissue damage and organ failure. A clinical enigma has been the variable clinical expression with some patients presenting with hepatic cirrhosis at a young age and others almost asymptomatic for life. Research is unravelling this puzzle by identifying environmental factors-especially alcohol consumption-and associated modifying genes that modulate phenotypic expression. A high index of suspicion is required for early diagnosis but this can lead to presymptomatic therapy and a normal life expectancy. Venesection (phlebotomy) therapy remains the mainstay of therapy, but alternative therapies are the subject of current research.

Alcoholic Liver Disease: High Risk or Low Risk for Developing Hepatocellular Carcinoma?

In this review we critically assess the literature to evaluate the level of risk posed by alcohol as both a primary etiology of hepatocellular carcinoma (HCC) and as a cofactor in its development. Although there have been conflicting findings, based on the body of evidence to date, it appears that the linkage between compensated alcoholic liver disease-associated cirrhosis and HCC is best characterized as medium-high risk, with the risk increasing with age and with quantity and duration of alcohol consumption and is more pronounced in females. While abstinence is the most effective way to reduce HCC risk, its effect seems largely dependent on the severity of liver damage at the point of cessation. Alcohol clearly interacts with other etiologies and conditions including viral hepatitis B and C, hereditary hemochromatosis, diabetes, and obesity to increase the risk for developing HCC, either synergistically or additively. Continued progress in genetics, especially through mechanistic-based and genome-wide association studies may ultimately identify which single nucleotide polymorphisms are risk factors for the onset of alcoholic liver disease and its progression to HCC and lead to the development of targeted therapeutics which may help providers better manage at-risk patients.

The Effects of Alcohol on Other Chronic Liver Diseases

Alcohol consumption is often a comorbid condition in other chronic liver diseases. It has been shown to act in synergy to increase liver injury in viral hepatitis, hereditary hemochromatosis, and nonalcoholic fatty liver disease (NAFLD), leading to an increased risk of cirrhosis, hepatocellular carcinoma, and liver-related mortality. Data suggest that modest alcohol consumption may be inversely related to the risk of developing NAFLD and lower rates of progression of NAFLD to nonalcoholic steatohepatitis (NASH). This article reviews data on the relationship between alcohol consumption and other chronic liver diseases.

Gender-Dimorphic Impact of PXR Genotype and Haplotype on Hepatotoxicity During Antituberculosis Treatment

Women have a higher risk of drug-induced hepatotoxicity during antituberculosis treatment (HATT) than men. We hypothesized that single nucleotide polymorphism (SNP) genotype and derived haplotype of pregnane X receptor (PXR) gene, which could regulate the expression of phase I enzyme cytochrome P450 (CYP) 3A4, had a sex-specific influence on the risk of HATT. Six SNPs of the PXR gene were sequenced. Genotypes and haplotypes of the PXR SNPs, and other potential risk factors for HATT were compared between pulmonary TB patients with and those without HATT. HATT was defined as an increase in serum transaminase level >3 times the upper limit of normal (ULN) with symptoms, or >5 times ULN without symptoms. We performed the study in a derivation and a validation cohort. Among the 355 patients with pulmonary TB in the derivation cohort, 70 (19.7%) developed HATT. Logistic regression analysis revealed the risk of HATT increased in female genotype AA at rs2461823 (OR: 6.87 [2.55-18.52]) and decreased in female genotype AA at rs7643645 (OR: 0.14 [0.02-1.02]) of PXR gene. Haplotype analysis showed that female h001101 (OR: 2.30 [1.22-4.32]) and female h000110 (OR: 2.25 [1.08-4.69]) haplotype were associated with increased HATT risk. The identified predictors were also significantly associated with female HATT risk among the 182 patients in the validation cohort. Two PXR SNP genotypes and 2 haplotypes influenced the risk of HATT only in females. The PXR SNP showed a sex-specific impact that contributed to an increased HATT risk in females.

Effects of strain and age on hepatic gene expression profiles in murine models of HFE-associated hereditary hemochromatosis

Hereditary hemochromatosis is an iron overload disorder most commonly caused by a defect in the HFE gene. While the genetic defect is highly prevalent, the majority of individuals do not develop clinically significant iron overload, suggesting the importance of genetic modifiers. Murine hfe knockout models have demonstrated that strain background has a strong effect on the severity of iron loading. We noted that hepatic iron loading in hfe-/- mice occurs primarily over the first postnatal weeks (loading phase) followed by a timeframe of relatively static iron concentrations (plateau phase). We thus evaluated the effects of background strain and of age on hepatic gene expression in Hfe knockout mice (hfe-/-). Hepatic gene expression profiles were examined using cDNA microarrays in 4- and 8-week-old hfe-/- and wild-type mice on two different genetic backgrounds, C57BL/6J (C57) and AKR/J (AKR). Genes differentially regulated in all hfe-/- mice groups, compared with wild-type mice, including those involved in cell survival, stress and damage responses and lipid metabolism. AKR strain-specific changes in lipid metabolism genes and C57 strain-specific changes in cell adhesion and extracellular matrix protein genes were detected in hfe-/- mice. Mouse strain and age are each significantly associated with hepatic gene expression profiles in hfe-/- mice. These affects may underlie or reflect differences in iron loading in these mice.

Novel loci affecting iron homeostasis and their effects in individuals at risk for hemochromatosis

Variation in body iron is associated with or causes diseases, including anaemia and iron overload. Here, we analyse genetic association data on biochemical markers of iron status from 11 European-population studies, with replication in eight additional cohorts (total up to 48,972 subjects). We find 11 genome-wide-significant (P<5 × 10(-8)) loci, some including known iron-related genes (HFE, SLC40A1, TF, TFR2, TFRC, TMPRSS6) and others novel (ABO, ARNTL, FADS2, NAT2, TEX14). SNPs at ARNTL, TF, and TFR2 affect iron markers in HFE C282Y homozygotes at risk for hemochromatosis. There is substantial overlap between our iron loci and loci affecting erythrocyte and lipid phenotypes. These results will facilitate investigation of the roles of iron in disease.

Transforming growth factor-β and toll-like receptor-4 polymorphisms are not associated with fibrosis in haemochromatosis

AIM: To investigate the role of genetic polymorphisms in the progression of hepatic fibrosis in hereditary haemochromatosis.

METHODS: A cohort of 245 well-characterised C282Y homozygous patients with haemochromatosis was studied, with all subjects having liver biopsy data and DNA available for testing. This study assessed the association of eight single nucleotide polymorphisms (SNPs) in a total of six genes including toll-like receptor 4 (TLR4), transforming growth factor-beta (TGF-β), oxoguanine DNA glycosylase, monocyte chemoattractant protein 1, chemokine C-C motif receptor 2 and interleukin-10 with liver disease severity. Genotyping was performed using high resolution melt analysis and sequencing. The results were analysed in relation to the stage of hepatic fibrosis in multivariate analysis incorporating other cofactors including alcohol consumption and hepatic iron concentration.

RESULTS: There were significant associations between the cofactors of male gender (P = 0.0001), increasing age (P = 0.006), alcohol consumption (P = 0.0001), steatosis (P = 0.03), hepatic iron concentration (P < 0.0001) and the presence of hepatic fibrosis. Of the candidate gene polymorphisms studied, none showed a significant association with hepatic fibrosis in univariate or multivariate analysis incorporating cofactors. We also specifically studied patients with hepatic iron loading above threshold levels for cirrhosis and compared the genetic polymorphisms between those with no fibrosis vs cirrhosis however there was no significant effect from any of the candidate genes studied. Importantly, in this large, well characterised cohort of patients there was no association between SNPs for TGF-β or TLR4 and the presence of fibrosis, cirrhosis or increasing fibrosis stage in multivariate analysis.

CONCLUSION: In our large, well characterised group of haemochromatosis subjects we did not demonstrate any relationship between candidate gene polymorphisms and hepatic fibrosis or cirrhosis.

Evidence for the high importance of co-morbid factors in HFE C282Y/H63D patients cared by phlebotomies: results from an observational prospective study

Despite type I haemochromatosis (HC) is mainly associated with the HFE C282Y/C282Y genotype, a second genotype -C282Y/H63D- has mostly been described in other patients. Its association with HC, apart from any associated co-morbid factors, remains unclear and complex to interpret for physicians. This study assesses the weight of this genotype and the role of co-morbid factors in the occurrence of iron overload. This prospective study included the C282Y/C282Y (n = 172) and C282Y/H63D (n = 58) patients enrolled in a phlebotomy program between 2004 and 2007 in a blood centre of western Brittany (Brest, France), where HC is frequent. We compared prevalence of these two genotypes, as well as patients' profile regarding degree of iron overload and prevalence of co-morbid factors. First, we confirmed the obvious deficit of C282Y/H63D compound heterozygotes among patients cared by phlebotomies. This genotype was 3.0 times less frequent than the C282Y/C282Y genotype among those patients (18.9% vs. 56.0%) whereas it was 4.9 times more frequent in the general population (4.3% vs. 0.9%; p<0.0001). Despite a similar level of hyperferritinaemia, the C282Y/H63D patients who came to medical attention had a milder plasma iron overload, reflected by a lower transferrin saturation median (52.0% vs. 84.0%; p<0.0001). They also exhibited more frequently co-morbid factors, as heavy drinking (26.0% vs. 13.9%; p = 0.0454), overweight (66.7% vs. 39.4%; p = 0.0005) or both (21.3% vs. 2.6%; p<0.0001). Ultimately, they required a lower amount of iron removed to reach depletion (2.1 vs. 3.4 g; p<0.0001), clearly reflecting their lower tissue iron. This study confirms that H63D is a discrete genetic susceptibility factor whose expression is most visible in association with other co-factors. It highlights the importance of searching for co-morbidities in these diagnostic situations and of providing lifestyle and dietary advice.

Relevance of dietary iron intake and bioavailability in the management of HFE hemochromatosis: a systematic review

BACKGROUND

Hereditary hemochromatosis (HH) leads to iron loading because of a disturbance in the negative-feedback mechanism between dietary iron absorption and iron status. The management of HH is achieved by repeated phlebotomies.

OBJECTIVE

We investigated whether HH patients would benefit from a diet with low iron intake and bioavailability.

DESIGN

We performed a systematic review of studies that linked iron bioavailability and status with dietary factors in subjects with diagnosed HH. Studies on heterozygotes for the HFE mutation were excluded.

RESULTS

No prospective, randomized study was reported. Nine studies that directly measured iron bioavailability from test meals in HH patients have been described as well as 3 small, prospective, longitudinal studies in HH patients. Eight cross-sectional studies were identified that investigated the effect of dietary composition on iron status. Calculations of iron bioavailability in HH were made by extrapolating data on hepcidin concentrations and their association with iron bioavailability. The potential reduction in the yearly amount of blood to be phlebotomized when restricting dietary iron absorbed was estimated in the 3 longitudinal studies and ranged between 0.5 and 1.5 L. This amount would be dependent on individual disease penetrance as well as the dietary intervention.

CONCLUSIONS

Despite the limited quantitative evidence and the lack of randomized, prospective trials, dietary interventions that modify iron intake and bioavailability may affect iron accumulation in HH patients. Although this measure may be welcome in patients willing to contribute to their disease management, limited data exist on the clinical and quality-of-life benefit.

HFE MUTATIONS AND IRON OVERLOAD IN PATIENTS WITH ALCOHOLIC LIVER DISEASE

ContextAlcoholic liver disease (ALD) is generally associated with iron overload, which may contribute to its pathogenesis, through increased oxidative stress and cellular damage. There are conflicting reports in literature about hemochromatosis (HFE) gene mutations and the severity of liver disease in alcoholic patients.ObjectivesTo compare the prevalence of mutations in the hemochromatosis (HFE) gene between patients with ALD and healthy controls; to assess the relation of HFE mutations with liver iron stores and liver disease severity.MethodsLiver biopsy specimens were obtained from 63 ALD patients (during routine treatment) and 52 healthy controls (during elective cholecystectomy). All individuals underwent routine liver function tests and HFE genotyping (to detect wild-type sequences and C282Y, H63D, S65C, E168Q, E168X, V59M, H63H, P160delC, Q127H, Q283P, V53M and W164X mutations). Associations between HFE mutations and risk of excessive liver iron stores, abnormal serum ferritin, liver fibrosis, or necroinflammatory activity were assessed by multivariate logistic regression analysis.ResultsALD patients had significantly higher serum ferritin and transferrin saturation than controls (both P<0.05), but the distribution of HFE mutations was similar between the two groups. For ALD patients, the odds ratio for having at least one HFE mutation and excessive liver iron stores was 17.23 (95% confidence interval (CI): 2.09-142.34, P = 0.008). However, the presence of at least one HFE mutation was not associated with an increased risk of liver fibrosis or necroinflammatory activity. Active alcohol ingestion showed the strongest association to increased serum ferritin (OR = 8.87, 95% CI: 2.11-34.78, P = 0.003).ConclusionsALD patients do not present with a differential profile of HFE mutations from healthy controls. In ALD patients, however, the presence of at least one HFE mutation increases the risk of having excessive liver iron stores but has no detectable effects on liver disease activity or severity.

Liver cancer and alcohol

Annually, hepatocellular carcinoma is diagnosed in approximately a half-million people worldwide. Based on the association of alcohol with cancer, a International Agency for Research on Cancer working group recently deemed alcoholic beverages "carcinogenic to humans," causally related to occurrence of malignant tumors of the oral cavity, pharynx, larynx, esophagus, liver, colorectum, and female breast. Alcohol metabolism in the liver leads to reactive oxygen species production, induction of activity of cytochrome P450s, and reduction of antioxidants. This review analyzes the epidemiology and pathogenesis of alcohol in hepatocellular cancer.

Alcohol's effect on other chronic liver diseases

In addition to directly causing liver disease, alcohol consumption is a common comorbid condition with other chronic liver diseases and may exacerbate liver injury, particularly in nonalcoholic fatty liver disease, chronic viral hepatitis, hereditary hemochromatosis, and autoimmune liver diseases. This synergism can result in increased hepatic inflammation and accelerated rates of fibrosis, with more rapid and earlier development of cirrhosis, and also increase the risk for liver cancer and death from liver disease.

Clinical cofactors and hepatic fibrosis in hereditary hemochromatosis: the role of diabetes mellitus

The risk of hepatic fibrosis and cirrhosis in hereditary hemochromatosis relates to the degree of iron loading, but iron alone does not explain the variability in disease penetrance. This study sought to identify clinical cofactors that increase the risk of progressive liver disease. We identified 291 patients from our database who were homozygous for the C282Y mutation in HFE and had undergone a liver biopsy with quantification of hepatic iron concentration (HIC) and fibrosis staging. Data were collected from a retrospective chart review, including age, gender, alcohol consumption, medical therapy, smoking history, metabolic risk factors, mobilizable iron, and laboratory results. Male gender, excess alcohol consumption, HIC, and the presence of diabetes were independently associated with increasing fibrosis stage in multivariate analysis. Of these, the presence of diabetes showed the strongest association (odds ratio, 7.32; P = 0.03). The presence of steatosis was associated with higher fibrosis scores, but this was of borderline statistical significance. Risk factors for hepatic steatosis were male gender, impaired glucose tolerance, and increased body mass index.

CONCLUSION

The presence of diabetes was associated with more severe hepatic fibrosis independent of iron loading, male gender, and alcohol consumption. The mechanism for this association is unknown and deserves further evaluation; however, it is possible that diabetes produces an additional hepatic oxidative injury from hyperglycemia. Thus, management of such cofactors in patients with hemochromatosis is important to reduce the risk of liver injury and fibrosis.

Hepatic iron deposition does not predict extrahepatic iron loading in mouse models of hereditary hemochromatosis

Hereditary hemochromatosis is characterized by tissue iron loading and associated organ damage. However, the phenotype can be highly variable. The relationship between iron loading of different organs and the temporal nature of its deposition is still not well understood. We examined the progression of tissue iron loading in three mouse models to advance our understanding of the natural history of iron deposition in hereditary hemochromatosis. Wild-type, Hfe(-/-), Tfr2(-/-), and Hfe(-/-)/Tfr2(-/-) mice were analyzed at 3, 5, 10, 26, and 52 weeks, respectively. Hepatic, splenic, cardiac, and pancreatic iron concentrations were determined. Expression of both iron-regulatory and fibrosis genes was determined by quantitative real-time PCR in livers and hearts of 52-week-old mice. In all models, hepatic iron increased rapidly, plateauing before 10 weeks at different levels, depending on the genotype. Iron deposition in the pancreas and heart occurred after maximal iron loading of the liver was reached and was most marked in the Hfe(-/-)/Tfr2(-/-) mice. Although a significant positive correlation was identified between pancreatic and cardiac iron in all models at 52 weeks, there was no correlation between hepatic and either pancreatic or cardiac iron. There is variability in the timing and extent of tissue iron loading within a genotype, suggesting that hepatic iron levels in hereditary hemochromatosis may not accurately predict the iron content of other organs.

Taxonomizing, sizing, and overcoming the incidentalome

PURPOSE

With the advent of whole-genome sequencing made clinically available, the number of incidental findings is likely to rise. The false-positive incidental findings are of particular clinical concern. We provide estimates on the size of these false-positive findings and classify them into four broad categories.

METHODS

Whole-genome sequences (WGS) of nine individuals were scanned with several comprehensive public annotation databases and average estimates for the number of findings. These estimates were then evaluated in the perspective of various sources of false-positive annotation errors.

RESULTS

At present there are four main sources of false-positive incidental findings: erroneous annotations, sequencing error, incorrect penetrance estimates, and multiple hypothesis testing. Of these, the first two are likely to be addressed in the near term. Conservatively, current methods deliver hundreds of false-positive incidental findings per individual.

CONCLUSION

The burden of false-positives in whole-genome sequence interpretation threatens current capabilities to deliver clinical-grade whole-genome clinical interpretation. A new generation of population studies and retooling of the clinical decision-support approach will be required to overcome this threat.

HFE-Related Hemochromatosis: The Haptoglobin 2-2 Type Has a Significant but Limited Influence on Phenotypic Expression of the Predominant p.C282Y Homozygous Genotype

Phenotypic expression of the common p.C282Y/p.C282Y HFE-related hemochromatosis genotype is heterogeneous and depends on a complex interplay of genetic and non-genetic factors. Haptoglobin has a crucial role in free hemoglobin iron recovery, and exists as three major types: Hp1-1, Hp2-1 and Hp2-2. Hp2-2 favors endocytosis of hemoglobin iron in monocytes/macrophages, resulting in partial iron retention and increased intracellular ferritin levels. This situation is generally not expected to severely affect iron homeostasis, but was found to correlate with elevated serum iron indices in healthy men. Whether the Hp2-2 genotype acts as a modifier in HFE-related hemochromatosis is unclear. In this study we investigated influence of Hp2-2 and of potential confounders on the iron indices of 351 p.C282Y homozygous patients. We conclude that there is a cause-and-effect relationship between the Hp2-2 genotype and increased iron indices in p.C282Y homozygous patients. The Hp2-2 effect is, however, limited and only apparent in males.

Genetics of hereditary hemochromatosis: a clinical perspective

Hereditary hemochromatosis due to homozygosity for the C282Y mutation in the HFE gene product is the most common autosomal recessive genetic disorder in populations of northern European descent, where it attains a maximum prevalence of approximately one in 200. Cross-sectional and longitudinal studies have revealed that clinically significant iron-overload disease develops in at least 28% of male and 1% of female HFE C282Y homozygotes. The relatively low clinical penetrance is largely unexplained. Current evidence suggests a limited role for digenic inheritance of mutations in iron homeostasis genes in modifying the penetrance of hemochromatosis. Male gender is a strong genetic factor, promoting expression of clinical disease. Dietary intake of alcohol and noncitrus fruit may also act as important environmental modifiers of penetrance. With genetic analyses becoming simpler to perform, new genetic modifiers of hepatic iron loading and liver fibrogenesis are likely to be forthcoming.

The twin questions of personalized medicine: who are you and whom do you most resemble?

Personalized medicine is typically described as the use of molecular or genetic characteristics to customize therapy. This perspective at best provides an incomplete model of the patient and at worst can lead to grossly inappropriate practices. Personalization of medicine requires two characterizations: a well-grounded understanding of who the patient is and an equally robust understanding of the subpopulation that most resembles that patient in the context of the decisions at hand. These characterizations are readily represented probabilistically and can be used to drive decision-making in a rational manner that maximizes the positive outcomes for the patient.

Co-factors in liver disease: the role of HFE-related hereditary hemochromatosis and iron

The severity of liver disease and its presentation is thought to be influenced by many host factors. Prominent among these factors is the level of iron in the body. The liver plays an important role in coordinating the regulation of iron homeostasis and is involved in regulating the level of iron absorption in the duodenum and iron recycling by the macrophages. Iron homeostasis is disturbed by several metabolic and genetic disorders, including various forms of hereditary hemochromatosis. This review will focus on liver disease and how it is affected by disordered iron homeostasis, as observed in hereditary hemochromatosis and due to HFE mutations. The types of liver disease covered herein are chronic hepatitis C virus (HCV) infection, alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), end-stage liver disease, hepatocellular carcinoma (HCC) and porphyria cutanea tarda (PCT).

Environmental and genetic modifiers of the progression to fibrosis and cirrhosis in hemochromatosis

Hereditary hemochromatosis is a genetic disorder of iron metabolism leading to inappropriate iron absorption and iron loading in various organs especially the liver. Despite the genetic mutation being relatively common in those of Anglo Celtic descent, cirrhosis of the liver occurs in only a small proportion of affected individuals. The risk of hepatic fibrosis and cirrhosis relates to the degree of iron loading with threshold hepatic iron concentrations being identified from population studies. However, other environmental and possibly genetic factors appear to modify this risk. Excess alcohol consumption appears to be one of the most important cofactors with steatosis and coexistent viral infection also implicated. Genetic polymorphisms in genes associated with fibrogenesis, antioxidant activity, and inflammation have been investigated in several different forms of chronic liver disease. The variability in the expression of these genes that predispose patients with hemochromatosis to increased risk of severe liver disease is the subject of ongoing investigations. Clearly the progression of iron loading to cirrhosis marks a crucial stage in the natural history of a patient's disease and therefore therapy and prognosis. This review explores recent developments in knowledge of environmental and genetic modifiers of this process.

Iron storage disease: facts, fiction and progress

There are many forms of iron storage disease, some hereditary and some acquired. The most common of the hereditary forms is HFE-associated hemochromatosis, and it is this disorder that is the main focus of this presentation. The body iron content is regulated by controlling absorption, and studies in the past decade have clarified, in part, how this regulation functions. A 25-amino-acid peptide hepcidin is up-regulated by iron and by inflammation, and it inhibits iron absorption and traps iron in macrophages by binding to and causing degradation of the iron transport protein ferroportin. Most forms of hemochromatosis results from dysregulation of hepcidin or defects of hepcidin or ferroportin themselves. Hereditary hemochromatosis was once considered to be very rare, but in the 1970s and 1980s, with the introduction of better diagnostic tests, it was considered the most common disease among Europeans. Controlled epidemiologic studies carried out in the last decade have shown, however, the disease itself actually is rare, and only its genotype and associated biochemical changes that are common. We do not understand why only a few homozygotes develop severe disease. It now seems unlikely that there are important modifying genes, and although alcohol is known to have some effect, excess drinking probably plays only a modest role in determining the hemochromatosis phenotype. Hereditary hemochromatosis is readily treated by phlebotomy. Secondary forms of the disease require chelation therapy, and the recent introduction of effective oral chelating agents is an important step forward in treating patients with disorders in which iron overload often proves to be fatal, such as thalassemia, myelodysplastic anemias, and dyserythropoietic anemias. While much has been learned about the regulation of iron homeostasis in the past decade, many mysteries remain and represent challenges that will keep us occupied for years to come.

Maximum number of live births per donor in artificial insemination

BACKGROUND

The maximal number of live births (k) per donor was usually determined by cultural and social perspective. It was rarely decided on the basis of scientific evidence or discussed from mathematical or probabilistic viewpoint.

METHODS AND RESULTS

To recommend a value for k, we propose three criteria to evaluate its impact on consanguinity and disease incidence due to artificial insemination by donor (AID). The first approach considers the optimization of k under the criterion of fixed tolerable number of consanguineous mating due to AID. The second approach optimizes k under fixed allowable average coefficient of inbreeding. This approach is particularly helpful when assessing the impact on the public, is of interest. The third criterion considers specific inheritance diseases. This approach is useful when evaluating the individual's risk of genetic diseases. When different diseases are considered, this criterion can be easily adopted. All these derivations are based on the assumption of shortage of gamete donors due to great demand and insufficient supply.

CONCLUSIONS

Our results indicate that strong degree of assortative mating, small population size and insufficient supply in gamete donors will lead to greater risk of consanguinity. Recommendations under other settings are also tabulated for reference. A web site for calculating the limit for live births per donor is available.

Hereditary hemochromatosis: genetic complexity and new diagnostic approaches

Since the discovery of the hemochromatosis gene (HFE) in 1996, several novel gene defects have been detected, explaining the mechanism and diversity of iron-overload diseases. At least 4 main types of hereditary hemochromatosis (HH) have been identified. Surprisingly, genes involved in HH encode for proteins that all affect pathways centered around liver hepcidin synthesis and its interaction with ferroportin, an iron exporter in enterocytes and macrophages. Hepcidin concentrations in urine negatively correlate with the severity of HH. Cytokine-mediated increases in hepcidin appear to be an important causative factor in anemia of inflammation, which is characterized by sequestration of iron in the macrophage system. For clinicians, the challenge is now to diagnose HH before irreversible damage develops and, at the same time, to distinguish progressive iron overload from increasingly common diseases with only moderately increased body iron stores, such as the metabolic syndrome. Understanding the molecular regulation of iron homeostasis may be helpful in designing innovative and reliable DNA and protein tests for diagnosis. Subsequently, evidence-based diagnostic strategies must be developed, using both conventional and innovative laboratory tests, to differentiate between the various causes of distortions of iron metabolism. This review describes new insights in mechanisms of iron overload, which are needed to understand new developments in diagnostic medicine.

The molecular genetics of haemochromatosis

The molecular basis of haemochromatosis has proved more complex than expected. After the 1996 identification of the main causative gene HFE and confirmation that most patients were homozygous for the founder C282Y mutation, it became clear that some families were linked to rarer conditions, first named 'non-HFE haemochromatosis'. The genetics of these less common forms was intensively studied between 2000 and 2004, leading to the recognition of haemojuvelin (HJV), hepcidin (HAMP), transferrin receptor 2 (TFR2) and ferroportin-related haemochromatosis, and opening the way for novel hypotheses such as those related to digenic modes of inheritance or the involvement of modifier genes. Molecular studies of rare haemochromatosis disorders have contributed to our understanding of iron homeostasis. In turn, recent findings from studies of knockout mice and functional studies have confirmed that HAMP plays a central role in mobilization of iron, shown that HFE, TFR2 and HJV modulate HAMP production according to the body's iron status, and demonstrated that HAMP negatively regulates cellular iron efflux by affecting the ferroportin cell surface availability. These data shed new light on the pathophysiology of all types of haemochromatosis, and offer novel opportunities to comment on phenotypic differences and distinguish mutations.

Genetic background of primary iron overload syndromes in Japan

The different prevalences of iron overload syndromes between Caucasians and Asians may be accounted for by the differences in genetic background. The major mutation of hemochromatosis in Celtic ancestry, C282Y of HFE, was reported in a Japanese patient. Five patients of 3 families with the hepatic transferrin receptor gene (TFR2)-linked hemochromatosis were found in different areas of Japan, suggesting that TFR2 is a major gene in Japanese people. Three patients with mutations in the hemojuvelin gene, HJV, showed also middle-age-onset hemochromatosis. A heterozygous mutation in the H ferritin gene, FTH1, was found in a family of 3 affected patients. Another autosomal dominant SLC40A1-linked hyperferritinemia (ferroportin disease) was found in 3 patients of 2 families. Two patients with hemochromatosis were free from any mutations in the genes investigated. In conclusion, the genetic backgrounds of Japanese patients with primary iron overload syndromes were partially clarified, showing some phenotype-genotype correlations.

Hemocromatosis hereditaria: estudio fenotípico de una población española

BACKGROUND AND OBJECTIVE

Hereditary hemochromatosis (HH) displays an important phenotypic variability and is a disease influenced by many factors.

PATIENTS AND METHOD

We included 88 patients with HH. Main clinical and laboratory data were analyzed, and the influence of 6 variables on intensity of iron overload was evaluated.

RESULTS

In 38.6% (95% confidence interval [CI], 28.5-49.6%) patients, none of the typical symptoms of the disease was observed. 30,9% (95% CI, 21.7-41.7%) showed abnormalities of the glucose metabolism. We detected an increase in sideremia in 75.0% patients (CI 95%, 64.4-83.3%), transferrin saturation index (TSI) in 95.4% (CI 95%, 88.1-98.5%) and ferritin in 93.2% (CI 95%, 85.1-97.1%) of patients. In addition, we observed increased values of GPT and alkaline phosphatase in an appreciable percentage of patients. Ferritin was significantly higher in men (1329.4 [913.2] ng/ml vs 656.6 [644.5] ng/ml; p < 0.001), and in those older than 45 years (1293.9 [1006.9] ng/ml vs 868.9 [642.8] ng/ml; p = 0.023] and in not blood donors (1205.2 [926.8] vs 524.8 [365.9] ng/ml; p < 0.001). TSI was 81.9% (19.6) in C282Y homozygotes and 65.7% (19.2) in the rest of HFE genotypes (p = 0.002). Differences of TSI with regard to sex, age or status of blood donor were not detected. Sideremia was significantly higher in patients infected by virus C (251.8 [24.4] microg/dl vs 182.8 [45.8] microg/dl; p = 0.001).

CONCLUSIONS

HH patients have a noticeable phenotypic variability, and for that reason clinical symptoms are only orientative for the diagnosis. The relationship between HH and glucose metabolism should be investigated further. Iron parameters can be influenced by age, sex, HFE genotype, blood donation, alcohol intake and hepatitis C virus infection.