Evidence that the Cys282Tyr mutation of the HFE gene originated from a population in Southern Scandinavia and spread with the Vikings

Historical navigation routes in European waters leave their footprint on the contemporary seascape genetics of a colonial urochordate

Humans have intensively sailed the Mediterranean and European Atlantic waters throughout history, from the upper Paleolithic until today and centuries of human seafaring have established complex coastal and cross-seas navigation networks. Historical literature revealed three major long-lasting maritime routes (eastern, western, northern) with four commencing locations (Alexandria, Venice, Genoa, Gibraltar) and a fourth route (circum-Italian) that connected between them. Due to oceangoing and technological constraints, most voyages were coastal, lasted weeks to months, with extended resting periods, allowing the development of fouling organisms on ship hulls. One of the abiding travellers in maritime routes is the colonial ascidian Botryllus schlosseri already known since the eighteenth century in European and Mediterranean ports. This species, was almost certainly one of the common hull fouling travellers in all trade routes for centuries. Employing COI haplotypes (1008 samples) and microsatellite alleles (995 samples) on colonies sampled from 64 pan-European sites, present-day Botryllus populations in the Mediterranean Sea/European Atlantic revealed significant segregation between all four maritime routes with a conspicuous partition of the northern route. These results reveal that past anthropogenic transports of sedentary marine species throughout millennia long seafaring have left their footprint on contemporary seascape genetics of marine organisms.

Genetic haemochromatosis: diagnosis and treatment of an iron overload disorder

Genetic haemochromatosis is a potentially serious iron overload disorder, yet there is a lack of awareness of the condition among the public and many healthcare professionals. In the UK, around one in 150 people have the genetic mutations that cause the condition, meaning that they are at increased risk of developing iron overload. If undiagnosed, prolonged iron overload can lead to liver, heart and endocrine failure and may be fatal; however, early diagnosis, treatment and maintenance can enable patients to have a normal lifespan. This article provides an overview of genetic haemochromatosis, including its types, origins, signs and symptoms, diagnosis, screening and treatment.

Hereditary hemochromatosis: data from a single center Copenhagen cohort

OBJECTIVES

We aimed to describe a cohort of hereditary hemochromatosis (HH) patients from a single urban center in Copenhagen.

METHODS

Retrospectively, data from patients with HH from the years 2009-2020 were collected.

RESULTS

A total of 203 patients was recorded. Males constituted 65.0% of the patients. Homozygous HH (HHH)/compound heterozygous HH (CHH) accounted for 69.4%/30.6%. HHH patients had significantly higher ferritin and transferrin saturation (TS) levels at debut than CHH patients. Fifty-five HHH patients (39.0%) had ferritin >1000 ug/L versus 9 (14.5%) in the CHH group (p < .001). Age at debut did not differ between female and male patients. Ferritin (but not TS) levels were significantly higher in male patients. The proportion of patients with ferritin >1000 did not differ between males and females. One-hundred patients (49.3%) had one or more symptoms at the time of diagnosis; arthralgias of the metacarpophalangeal joints and/or ankles (n = 46 (22.7%)), fatigue (n = 67 (33.0%)) and decreased libido (n = 20 (9.9%)). The proportion of patients with symptoms did not differ between HHH and CHH or between male and female patients. Severe organ complications (cardiomyopathy, late onset type 1 diabetes or cirrhosis) were present in 14 patients (6.9%).

CONCLUSIONS

We report a high proportion of compound HH, constituting almost one-third of patients. We found that the proportion of patients with symptoms did not differ between HHH and CHH and recommend that CHH should be treated and examined in the same way as HHH.

Epidemiological aspects of hereditary fructose intolerance: A database study

Hereditary fructose intolerance (HFI) is an inborn error of fructose metabolism of autosomal recessive inheritance caused by pathogenic variants in the ALDOB gene that lead to aldolase B deficiency in the liver, kidneys, and intestine. Patients manifest symptoms, such as ketotic hypoglycemia, vomiting, nausea, in addition to hepatomegaly and other liver and kidney dysfunctions. The treatment consists of a fructose-restricted diet, which results in a good prognosis. To analyze the distribution of ALDOB variants described in patients and to estimate the prevalence of HFI based on carrier frequency in the gnomAD database, a systematic review was conducted to assess ALDOB gene variants among patients with HFI. The prevalence of HFI was estimated from the carrier frequency of variants described in patients, as well as rare variants predicted as pathogenic by in silico tools. The p.(Ala150Pro) and p.(Ala175Asp) variants are the most frequent and are distributed worldwide. However, these variants have particular distribution patterns in Europe. The analysis of the prevalence of HFI showed that the inclusion of rare alleles predicted as pathogenic is a more informative approach for populations with few patients. The data show that HFI has a wide distribution and an estimated prevalence of ~1:10,000.

Ethnic Differences in Iron Status

Iron is unique among all minerals in that humans have no regulatable excretory pathway to eliminate excess iron after it is absorbed. Iron deficiency anemia occurs when absorbed iron is not sufficient to meet body iron demands, whereas iron overload and subsequent deposition of iron in key organs occur when absorbed iron exceeds body iron demands. Over time, iron accumulation in the body can increase risk of chronic diseases, including cirrhosis, diabetes, and heart failure. To date, only ∼30% of the interindividual variability in iron absorption can be captured by iron status biomarkers or iron regulatory hormones. Much of the regulation of iron absorption may be under genetic control, but these pathways have yet to be fully elucidated. Genome-wide and candidate gene association studies have identified several genetic variants that are associated with variations in iron status, but the majority of these data were generated in European populations. The purpose of this review is to summarize genetic variants that have been associated with alterations in iron status and to highlight the influence of ethnicity on the risk of iron deficiency or overload. Using extant data in the literature, linear mixed-effects models were constructed to explore ethnic differences in iron status biomarkers. This approach found that East Asians had significantly higher concentrations of iron status indicators (serum ferritin, transferrin saturation, and hemoglobin) than Europeans, African Americans, or South Asians. African Americans exhibited significantly lower hemoglobin concentrations compared with other ethnic groups. Further studies of the genetic basis for ethnic differences in iron metabolism and on how it affects disease susceptibility among different ethnic groups are needed to inform population-specific recommendations and personalized nutrition interventions for iron-related disorders.

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.

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.

Diagnosis and Treatment of Genetic HFE-Hemochromatosis: The Danish Aspect

This paper outlines the Danish aspects of HFE-hemochromatosis, which is the most frequent genetic predisposition to iron overload in the five million ethnic Danes; more than 20,000 people are homozygous for the C282Y mutation and more than 500,000 people are compound heterozygous or heterozygous for the HFE-mutations. The disorder has a long preclinical stage with gradually increasing body iron overload and eventually 30% of men will develop clinically overt disease, presenting with symptoms of fatigue, arthralgias, reduced libido, erectile dysfunction, cardiac disease and diabetes. Subsequently the disease may progress into irreversible arthritis, liver cirrhosis, cardiomyopathy, pancreatic fibrosis and osteoporosis. The effective standard treatment is repeated phlebotomies, which in the preclinical and early clinical stages ensures a normal survival rate. Early detection of the genetic predisposition to the disorder is therefore important to reduce the overall burden of clinical disease. Population screening seems to be cost-effective and should be considered.

Genomic and Strontium Isotope Variation Reveal Immigration Patterns in a Viking Age Town

The impact of human mobility on the northern European urban populations during the Viking and Early Middle Ages and its repercussions in Scandinavia itself are still largely unexplored. Our study of the demographics in the final phase of the Viking era is the first comprehensive multidisciplinary investigation that includes genetics, isotopes, archaeology, and osteology on a larger scale. This early Christian dataset is particularly important as the earlier common pagan burial tradition during the Iron Age was cremation, hindering large-scale DNA analyses. We present genome-wide sequence data from 23 individuals from the 10^th to 12^th century Swedish town of Sigtuna. The data revealed high genetic diversity among the early urban residents. The observed variation exceeds the genetic diversity in distinct modern-day and Iron Age groups of central and northern Europe. Strontium isotope data suggest mixed local and non-local origin of the townspeople. Our results uncover the social system underlying the urbanization process of the Viking World of which mobility was an intricate part and was comparable between males and females. The inhabitants of Sigtuna were heterogeneous in their genetic affinities, probably reflecting both close and distant connections through an established network, confirming that early urbanization processes in northern Europe were driven by migration.

Iron status in pregnant women and women of reproductive age in Europe

Understanding the iron status in pregnant women in Europe provides a foundation for considering the role of iron screening and supplementation. However, available reports and studies have used different approaches that challenge the devising of overall summaries. Moreover, data on pregnant women are limited, and thus, data on women of reproductive age provide useful background information including baseline iron stores in pregnant women. This review considered data that are available from >15 European countries including national surveys and relevant clinical studies. In European women of reproductive age, median or geometric mean serum ferritin (SF) concentrations were estimated at 26-38 μg/L. Approximately 40-55% of this population had small or depleted iron stores (i.e., SF concentration ≤30 μg/L), and 45-60% of this population had apparently replete iron stores. The prevalence of iron deficiency (ID) and iron deficiency anemia (IDA) was 10-32% and 2-5%, respectively, depending on the cutoffs used. Approximately 20-35% of European women of reproductive age had sufficient iron stores (SF concentration >70 μg/L) to complete a pregnancy without supplementary iron. During pregnancy, European women in controlled supplementation trials who were not receiving iron supplements displayed increasing prevalences of ID and IDA during pregnancy, which peaked in the middle to late third trimester. Available evidence has suggested that, in gestational weeks 32-39, the median or geometric mean SF concentrations were 6-21 μg/L, and prevalences of ID and IDA were 28-85% and 21-35%, respectively. Women who were taking iron supplements had higher iron status and lower prevalences of ID and IDA, which were dependent on the dose of iron and compliance. The data suggest that, in Europe, the iron status of reproductive-aged women varies by region and worsens in pregnancy without iron supplementation.

C282Y/H63D hemochromatosis mutations and microevolution: Speculations concerning the Basque population

The Basques live at the Western extremity of the Pyrenees. According to linguistic and genetic data they could be considered as one of the most ancient European populations. Numerous studies have evidenced particular patterns in the frequency of several genetic polymorphisms in this relatively unmixed human group. We discuss herein the puzzling distribution of the two major hemochromatosis HFE mutations associated with hereditary hemochromatosis. Thus, one can observe a low frequency of C282Y and, in contrast, one of the highest European frequencies of H63D. Genetic drift (enhanced by the long history and the small size of this population), long persistence of Paleolithic iron-rich diet, lower exposure to major infectious threats and limited mixing with both Celts and Vikings (who demonstrate the highest prevalence of C282Y) could be the underlying factors explaining these particular genetic features. Historical and environmental data represent key elements for understanding the role of the different evolutionary forces which shape the genetic profile of human populations.

The evolutionary adaptation of the C282Y mutation to culture and climate during the European Neolithic

OBJECTIVES

The C282Y allele is the major cause of hemochromatosis as a result of excessive iron absorption. The mutation arose in continental Europe no earlier than 6,000 years ago, coinciding with the arrival of the Neolithic agricultural revolution. Here we hypothesize that this new Neolithic diet, which originated in the sunny warm and dry climates of the Middle East, was carried by migrating farmers into the chilly and damp environments of Europe where iron is a critical micronutrient for effective thermoregulation. We argue that the C282Y allele was an adaptation to this novel environment.

MATERIALS AND METHODS

To address our hypothesis, we compiled C282Y allele frequencies, known Neolithic sites in Europe and climatic data on temperature and rainfall for statistical analysis.

RESULTS

Our findings indicate that the geographic cline for C282Y frequency in Europe increases as average temperatures decrease below 16°C, a critical threshold for thermoregulation, with rainy days intensifying the trend.

DISCUSSION

The results indicate that the deleterious C282Y allele, responsible for most cases of hemochromatosis, may have evolved as a selective advantage to culture and climate during the European Neolithic.

High prevalence of hereditary thrombotic thrombocytopenic purpura in central Norway: from clinical observation to evidence

Essentials The population prevalence of hereditary thrombotic thrombocytopenic purpura (TTP) is unknown. We studied the prevalence of hereditary TTP and population frequencies of two ADAMTS-13 mutations. A high frequency of hereditary TTP related to ADAMTS-13 mutation c.4143_4144dupA was found. Vicinity of ABO blood group and ADAMTS-13 loci may facilitate screening of ADAMTS-13 mutations.

SUMMARY

Background Hereditary thrombotic thrombocytopenic purpura (TTP) caused by ADAMTS-13 mutations is a rare, but serious condition. The prevalence is unknown, but it seems to be high in Norway. Objectives To identify all patients with hereditary TTP in central Norway and to investigate the prevalence of hereditary TTP and the population frequencies of two common ADAMTS-13 mutations. Patients/Methods Patients were identified in a cross-sectional study within the Central Norway Health Region by means of three different search strategies. Frequencies of ADAMTS-13 mutations, c.4143_4144dupA and c.3178 C>T (p.R1060W), were investigated in a population-based cohort (500 alleles) and in healthy blood donors (2104 alleles) by taking advantage of the close neighborhood of the ADAMTS-13 and ABO blood group gene loci. The observed prevalence of hereditary TTP was compared with the rates of ADAMTS-13 mutation carriers in different geographical regions. Results We identified 11 families with hereditary TTP in central Norway during the 10-year study period. The prevalence of hereditary TTP in central Norway was 16.7 × 10(-6) persons. The most prevalent mutation was c.4143_4144dupA, accounting for two-thirds of disease causing alleles among patients and having an allelic frequency of 0.33% in the central, 0.10% in the western, and 0.04% in the southeastern Norwegian population. The allelic frequency of c.3178 C>T (p.R1060W) in the population was even higher (0.3-1%), but this mutation was infrequent among patients, with no homozygous cases. Conclusions We found a high prevalence of hereditary TTP in central Norway and an apparently different penetrance of ADAMTS-13 mutations.

Ancestral association between HLA and HFE H63D and C282Y gene mutations from northwest Colombia

A significant association between HFE gene mutations and the HLA-A*03-B*07 and HLA-A*29-B*44 haplotypes has been reported in the Spanish population. It has been proposed that these mutations are probably connected with Celtic and North African ancestry, respectively. We aimed to find the possible ancestral association between HLA alleles and haplotypes associated with the HFE gene (C282Y and H63D) mutations in 214 subjects from Antioquia, Colombia. These were 18 individuals with presumed hereditary hemochromatosis (“HH”) and 196 controls. The HLA-B*07 allele was in linkage disequilibrium (LD) with C282Y, while HLA-A*23, A*29, HLA-B*44, and B*49 were in LD with H63D. Altogether, our results show that, although the H63D mutation is more common in the Antioquia population, it is not associated with any particular HLA haplotype, whereas the C282Y mutation is associated with HLA-A*03-B*07, this supporting a northern Spaniard ancestry.

Unique frequencies of HFE gene variants in Roma/Gypsies

The aim of this study was to assess the frequencies of three hemochromatosis gene (HFE) mutations in ethnic Roma/Gypsies in Slovakia. A cohort of 367 individuals representing general population and not preselected for health status was genotyped by TaqMan real-time PCR assay for C282Y, H63D and S65C mutations in HFE gene. A unique genetic profile was revealed: C282Y is found in the highest frequency of all Central European countries (4.90%), while the frequency of H63D mutation (4.09%) is lower than any reported in Europe so far. S65C mutation was not present in the cohort. These mutation frequencies can be explained rather by gene influx and genetic isolation than by genetic inheritance from a former Roma/Gypsy homeland.

Hemochromatosis gene and nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND & AIMS

Previous studies examining the relationship between the C282Y and H63D HFE mutations and presence of nonalcoholic fatty liver disease (NAFLD) have yielded conflicting results. The goal of this study was to systematically evaluate and summarize data on the association between these two variants and the presence of NAFLD.

METHODS

The authors searched EMBASE and PUBMED from August 1, 1996 to August 12, 2010. Two investigators independently conducted data abstraction. Ethnic specific weighted prevalence was calculated and pooled odds ratios were estimated using the random effects model.

RESULTS

From 2542 references, the authors included 16 case-control studies and 14 case-only studies, or 2610 cases and 7298 controls. The majority of the studies came from Caucasian populations (2287 cases and 4275 controls). The weighted prevalence of HFE mutations in cases was comparable to controls. The meta-analysis was restricted to Caucasians only because of the small sample size of non Caucasian participants. The pooled odds ratio for the presence of any HFE genetic variant in cases was 1.03 (95%CI: 0.90, 1.17; I(2): 65.8%, 95%CI: 38.5, 81.0). The presence of other genotypes and secondary analyses yielded similar non significant findings.

CONCLUSIONS

Our systematic review does not support an association between the HFE genetic variants and the presence of NAFLD.

Prevalence of C282Y, H63D, and S65C mutations in hereditary HFE-hemochromatosis gene in Lithuanian population

HFE-hemochromatosis is a common autosomal recessive disease caused by HFE gene mutations and characterized as iron overload and failure of different organs. The aim of this study was to determine the prevalence of C282Y (c.845 G>A), H63D (c.187 C>G), and S65C (c.193A>T) alleles of HFE gene in the Lithuanian population. One thousand and eleven healthy blood donors of Lithuanian nationality were examined in four different ethnic Lithuanian regions to determine HFE gene alleles and genotype frequencies. The samples of DNA were analyzed for the presence of restriction fragment length polymorphism and validated by DNA sequencing. Among 1,011 blood donors tested, the frequency of C282Y, H63D, and S65C alleles were 2.6%, 15.9%, and 1.9%, respectively. One third of the tested subjects (n = 336) had at least one of the C282Y or H63D HFE gene mutations. The screening of Lithuanian blood donors has detected 13 (1.3%) subjects with a genotype C282Y/C282Y or C282Y/H63D responsible for the development of HFE-hemochromatosis. The prevalence of C282Y mutation was significantly higher among the inhabitants of Zemaitija (Somogitia) at the Baltic Sea area (5.9%) in comparison to the regions of continental part of Lithuania (2.4% in Dzukija, 2.3% in Aukstaitija, and 2% in Suvalkija, p < 0.05). These data support the hypothesis that the p.C282Y mutation originated from Scandinavia and spread with the Vikings along the Baltic Sea coast. The first epidemiological investigation of HFE gene mutations in ethnic Lithuanians showed that the frequencies of H63D, C282Y, and S65C of HFE gene alleles are similar to the other North-Eastern Europeans, especially in the Baltic region (Estonia, Latvia), Poland, and part of Russia (Moscow region).

Prevalence of 845G>A HFE mutation in Slavic populations: an east-west linear gradient in South Slavs

AIM

To compare A allele frequencies of the 845G>A mutation of 10 Slavic populations in central, eastern, and southern Europe between each other and with other European populations.

METHODS

The 845G>A mutation from the DNA of 400 Polish neonates collected in 2005-2006 was analyzed by polymerase chain reaction-restriction fragment length polymorphism. The data were compared with reports from other countries.

RESULTS

We identified 381 GG homozygotes, 18 GA heterozygotes, and 1 AA homozygote. The 845A allele frequency was 2.5%, which makes the summary figure for Poland from this and previous studies 3.5%. The average prevalence for Poland and other West Slavic countries was 3.6%, similar to Russia (inhabited by the East Slavs, 3.5%). The average prevalence in South Slavic countries was 2.2%, gradually decreasing from 3.6% in Slovenia to 0% in Bulgaria, with a longitudinal linear gradient (adjusted R(2)=0.976, P<0.001).

CONCLUSIONS

The West and East Slavs, together with Finland, Estonia, Germany, Austria, Hungary, Slovenia, and Croatia, form a group with 845A allele frequencies between 3% and 4%. In the South Slavs, there is a gradual decline in the prevalence of 845A allele from northwest to southeast, with a surprisingly exact east-west linear gradient.

Anemia--still a major health problem in many parts of the world!

Anemia is a major global health problem, especially in developing countries. This fundamental health issue still has not been solved and continues to exist affecting the health, quality of life, and working capacity in billions of people all over the world. This paper gives a review on the prevalence and major causes of anemia seen on a global scale. Most cases of anemia are due to iron deficiency, which often work in symphony with folate deficiency and/or vitamin B12 deficiency as well as with infections. More efforts should be dedicated to tackle this massive problem--we have the tools, and we know the ways. Iron fortification of appropriate food items combined with iron supplements in specific population groups has proven to be efficient. Initially, the efforts should be centered on the specific risk groups for iron deficiency anemia, i.e., young children, adolescent females, women of reproductive age, as well as pregnant women and postpartum lactating mothers.

Was the C282Y mutation an Irish Gaelic mutation that the Vikings helped disseminate? HLA haplotype observations of hemochromatosis from the west coast of Sweden

The HLA-related hemochromatosis mutation C282Y is thought to have originated in Ireland in a person with HLA-A3-B14 and was spread by Vikings. Irish people with two HLA-A3 alleles had a high risk of hemochromatosis. In this study, from west Sweden, we wanted to test these hypotheses.

METHODS

HFE mutations in controls, bone marrow donors with HLA-A3/A3 and patients with hemochromatosis. HLA haplotypes, extended haplotype analysis and pedigree studies.

RESULTS

The allelic C282Y frequency 0.04, (CI 0.01-0.07) was lower (P < 0.001) in Sweden than in Ireland 0.10 (CI 0.08-0.11), and Swedish bone marrow donors with HLA-A3/A3 (n = 77) had a low risk of hemochromatosis. HLA haplotypes available from 239/262 (91.5%) proband patients homozygous for C282Y showed a dominance of A3-B7 and A3-B14 both in linkage disequilibrium with controls (P < 0.001). Pedigree studies extended into the 17th century supported a local founder effect of A3-B14 in the county of Bohuslän. The A3-B14 haplotype may well be the original and A3-B7 the result of centromeric recombinations. The haplotype diversity and recombination events were not different from a Celtic series. These findings do not support the hypothesis of the C282Y mutation being of an Irish Celtic origin.

CONCLUSIONS

The C282Y frequency shows a west to east decline from Ireland through the north of Europe. Vikings may have been involved in the spread of C282Y, but the mutation is probably older and may have been spread in Europe by earlier seafarers.

New RAB3GAP1 mutations in patients with Warburg Micro Syndrome from different ethnic backgrounds and a possible founder effect in the Danish

Warburg Micro Syndrome is a rare, autosomal recessive syndrome characterized by microcephaly, microphthalmia, microcornia, congenital cataracts, optic atrophy, cortical dysplasia, in particular corpus callosum hypoplasia, severe mental retardation, spastic diplegia, and hypogonadism. We have found five new mutations in the RAB3GAP1 gene in seven patients with suspected Micro Syndrome from families with Turkish, Palestinian, Danish, and Guatemalan backgrounds. A thorough clinical investigation of the patients has allowed the delineation of symptoms that are consistently present in the patients and may aid the differential diagnosis of Micro Syndrome for patients in the future. All patients had postnatal microcephaly, micropthalmia, microcornia, bilateral congenital cataracts, short palpebral fissures, optic atrophy, severe mental retardation, and congenital hypotonia with subsequent spasticity. Only one patient had microcephaly at birth, highlighting the fact that congenital microcephaly is not a consistent feature of Micro syndrome. Analysis of the brain magnetic resonance imagings (MRIs) revealed a consistent pattern of polymicrogyria in the frontal and parietal lobes, wide sylvian fissures, a thin hypoplastic corpus callosum, and increased subdural spaces. All patients were homozygous for the mutations detected and all mutations were predicted to result in a truncated RAB3GAP1 protein. The analysis of nine polymorphic markers flanking the RAB3GAP1 gene showed that the mutation c.1410C>A (p.Tyr470X), for which a Danish patient was homozygous, occurred on a haplotype that is shared by the unrelated heterozygous parents of the patient. This suggests a possible founder effect for this mutation in the Danish population.

An extensive analysis of the hereditary hemochromatosis gene HFE and neighboring histone genes: associations with childhood leukemia

The most common mutation of the HFE gene C282Y has shown a risk association with childhood acute lymphoblastic leukemia (ALL) in Welsh and Scottish case-control studies. This finding has not been replicated outside Britain. Here, we present a thorough analysis of the HFE gene in a panel of HLA homozygous reference cell lines and in the original population sample from South Wales (117 childhood ALL cases and 414 newborn controls). The 21 of 24 variants analyzed were from the HFE gene region extending 52 kb from the histone gene HIST1H1C to HIST1H1T. We identified the single-nucleotide polymorphism (SNP) rs807212 as a tagging SNP for the most common HFE region haplotype, which contains wild-type alleles of all HFE variants examined. This intergenic SNP rs807212 yielded a strong male-specific protective association (per allele OR = 0.38, 95% CI = 0.22-0.64, P (trend) = 0.0002; P = 0.48 in females), which accounted for the original C282Y risk association. In the HapMap project data, rs807212 was in strong linkage disequilibrium with 25 other SNPs spanning 151 kb around HFE. Minor alleles of these 26 SNPs characterized the most common haplotype for the HFE region, which lacked all disease-associated HFE variants. The HapMap data suggested positive selection in this region even in populations where the HFE C282Y mutation is absent. These results have implications for the sex-specific associations observed in this region and suggest the inclusion of rs807212 in future studies of the HFE gene and the extended HLA class I region.

[Hemochromatosis--from an underdiagnosed curiosity to a common disease]

BACKGROUND

Hemochromatosis is a common disease with a good prognosis, when diagnosed early and treated appropriately. The aim of this overview is to give updated information on hemochromatosis with special focus on biochemical features, diagnosis and treatment.

MATERIAL AND METHODS

This article is based on our own experience and a review of available literature in various databases such as PubMed and Medline.

RESULTS

Hereditary hemochromatosis is an autosomal recessive disease characterized by iron overload due to increased intestinal iron uptake over many years. Hemochromatosis is often discovered through coincidental detection of high levels of transferrin and/or ferritin. The early symptoms are asthenia and joint pain. About 85 % of patients with hereditary hemochromatosis are homozygote for the C282Y mutation in the HFE: gene, but the majority of homozygotes remain asymptomatic. With ferritin levels > 500 microg/, both hereditary hemochromatosis and iron overload (of unknown cause) are treated with blood-letting.

INTERPRETATION

The pathogenesis is not fully elucidated but recent reports indicate that the protein hepcidin (produced in the liver) plays a key role in the development of hemochromatosis. Iron overload may also be secondary to other diseases such as thalassemia and other conditions requiring multiple long-term blood transfusions. The goal is to maintain ferritin values at approximately 20 - 50 microg/L.

Extrinsic factors modifying expressivity of the HFE variant C282Y, H63D, S65C phenotypes in 1,294 Danish men

This study analysed the influence of extrinsic factors on the phenotypic expression of HFE gene variants in ethnic Danish men. A cohort of 6,020 men aged 30-53 years was screened for HFE C282Y, H63D and S65C variants. Serum iron, serum transferrin, transferrin saturation, and serum ferritin were analysed in 1,452 men and 1,294 men completed a questionnaire on factors, which could influence iron balance. The C282Y allele was present in 5.6%, H63D in 12.8% and S65C in 1.8% of the men. In the entire series, 3% had elevated iron status markers (transferrin saturation > or =50%, ferritin > or =300 microg/L). Self-reported liver disease had an elevating effect and peptic ulcer a lowering effect on iron status markers. Age increased the fraction of men with elevated ferritin from 8.3% at 32-38 years to 16.2% at 46-53 years of age (p = 0.002). Blood donation had a lowering effect on iron status markers (p = 0.0001). Alcohol consumption elevated serum iron and serum ferritin (p = 0.001). Meat consumption had an elevating effect (p = 0.02) and milk consumption a lowering effect (p = 0.03) on serum ferritin. There was no influence of vitamin-mineral tablets on iron status markers. In adjusted logistic regression analysis, the HFE genotype had the highest impact on iron status markers; high alcohol consumption was significantly associated with elevated transferrin saturation. High age and high alcohol consumption were significantly associated with elevated ferritin and high egg consumption and blood donation was significantly associated with normal ferritin levels. In conclusion, the expressivity of HFE variant phenotypes in Danish men was enhanced by alcohol and meat consumption and decreased by milk and egg consumption and blood donation.

Is the European spatial distribution of the HIV-1-resistant CCR5-Delta32 allele formed by a breakdown of the pathocenosis due to the historical Roman expansion?

We studied the possible effects of the expansion of ancient Mediterranean civilizations during the five centuries before and after Christ on the European distribution of the mutant allele for the chemokine receptor gene CCR5 which has a 32-bp deletion (CCR5-Delta32). There is a strong evidence for the unitary origin of the CCR5-Delta32 mutation, this it is found principally in Europe and Western Asia, with generally a north-south downhill cline frequency. Homozygous carriers of this mutation show a resistance to HIV-1 infection and a slower progression towards AIDS. However, HIV has clearly emerged too recently to have been the selective force on CCR5. Our analyses showed strong negative correlations in Europe between the allele frequency and two historical parameters, i.e. the first colonization dates by the great ancient Mediterranean civilizations, and the distances from the Northern frontiers of the Roman Empire in its greatest expansion. Moreover, other studies have shown that the deletion frequencies in both German Bronze Age and Swedish Neolithic populations were similar to those found in the corresponding modern populations, and this deletion has been found in ancient DNA of around 7000 years ago, suggesting that in the past, the deletion frequency could have been relatively high in European populations. In addition, in West Nile virus pathogenesis, CCR5 plays an antimicrobial role showing that host genetic factors are highly pathogen-specific. Our results added to all these previous data suggest that the actual European allele frequency distribution might not be due to genes spreading, but to a negative selection resulting in the spread of pathogens principally during Roman expansion. Indeed, as gene flows from colonizers to European native populations were extremely low, the mutational changes might be associated with vulnerability to imported infections. To date, the nature of the parasites remains unknown; however, zoonoses could be incriminated.

Frequencies of the haemochromatosis gene (HFE) variants C282Y, H63D and S65C in 6,020 ethnic Danish men

The objective was to assess the frequencies of haemochromatosis (HFE) gene mutations or variants C282Y, H63D and S65C in ethnic Danes. This is a prospective epidemiologic population study. A cohort of 6,020 Danish men aged 30-50 years was screened for HFE C282Y (c845G-->A), H63D (c187C-->G) and S65C (c193A-->T) gene variants, assessed on saliva or blood samples by restriction fragment length polymorphism (RFLP) analysis. The C282Y gene variant allele was present in 5.6%, H63D in 12.8% and S65C in 1.8% of the chromosomes. In the entire series, we observed 1.4% H63D/C282Y, 0.1% S65C/C282Y and 0.4% H63D/S65C compound heterozygotes. The C282Y allele frequency in Denmark is of similar order as reported in other Scandinavian countries: Iceland 5.1%, Faeroe Islands 6.6%, Norway 6.8% and Sweden 5.8%. Also, the H63D frequency in Denmark is close to the frequencies in other Scandinavian countries: Iceland 10.9%, Faeroe Islands 15.2%, Norway 11.4% and Sweden 12.1%.

HLA haplotype map of river valley populations with hemochromatosis traced through five centuries in Central Sweden

BACKGROUND

The hemochromatosis mutation, C282Y of the HFE gene, seems to have originated from a single event which once occurred in a person living in the north west of Europe carrying human leukocyte antigen (HLA)-A3-B7. In descendants of this ancestor also other haplotypes appear probably caused by local recombinations and founder effects. The background of these associations is unknown. Isolated river valley populations may be fruitful for the mapping of genetic disorders such as hemochromatosis. In this study, we try to test this hypothesis in a study from central Sweden where the haplotyope A1-B8 was common.

METHODS

HLA haplotypes and HFE mutations were studied in hemochromatosis patients with present or past parental origin in a sparsely populated (1/km(2)) rural district (n = 8366 in the year of 2005), in central Sweden. Pedigrees were constructed from the Swedish church book registry. Extended haplotypes were studied to evaluate origin of recombinations.

RESULTS

There were 87 original probands, 36 females and 51 males identified during 30 yr, of whom 86% carried C282Y/C282Y and 14% C282Y/H63D. Of 32 different HLA haplotypes A1-B8 was the most common (34%), followed by A3-B7 (16%), both in strong linkage disequilibrium with controls, (P < 0.001). Twenty-nine different families with A1-B8 had a common founder origin 15 generations ago in small bottleneck populations of the late 16th century. A second A1-B8 founder born 1655 was of Norwegian origin. Most of the A3 carriers (n = 26) had a common founder origin 16 generations ago in an even smaller nearby river valley. A fourth founder family carrying HLA-A2 seems to have originated from a recombination along the descendant lines from the A3 ancestor supported by extended haplotype studies. A1-haplotypes with alleles at the B locus different from B8 had a similar recombination origin as HLA-A2 alleles and a common founder origin 11 generations ago. The intergenerational time interval averaged 35.5 +/- 7.9 yr in men and 31.9 +/- 5.9 in females.

CONCLUSIONS

River valley populations may contain HLA haplotypes reflecting their demographic history. This study has demonstrated that the resistance against recombinations between HLA-A and HFE make HLA haplotypes excellent markers for population movements. Founder effects and genetic drift from bottleneck populations (surviving the plague?) may explain the commonness of the mutation in central Scandinavia. The intergenerational time difference >30 yr was greater than expected and means that the age of the original mutation may be underestimated.

Prevalence of H63D, S65C and C282Y hereditary hemochromatosis gene mutations in Slovenian population by an improved high-throughput genotyping assay

BACKGROUND

Hereditary hemochromatosis (HH) is a common genetic disease characterized by excessive iron overload that leads to multi-organ failure. Although the most prevalent genotype in HH is homozygosity for C282Y mutation of the HFE gene, two additional mutations, H63D and S65C, appear to be associated with a milder form of HH. The aim of this study was to develop a high-throughput assay for HFE mutations screening based on TaqMan technology and to determine the frequencies of HFE mutations in the Slovenian population.

METHODS

Altogether, 1282 randomly selected blood donors from different Slovenian regions and 21 HH patients were analyzed for the presence of HFE mutations by an in-house developed real-time PCR assay based on TaqMan technology using shorter non-interfering fluorescent single nucleotide polymorphism (SNP)-specific MGB probes. The assay was validated by RFLP analysis and DNA sequencing.

RESULTS

The genotyping assay of the H63D, S65C and C282Y mutations in the HFE gene, based on TaqMan technology proved to be fast, reliable, with a high-throughput capability and 100% concordant with genotypes obtained by RFLP and DNA sequencing. The observed frequency of C282Y homozygotes in the group of HH patients was only 48%, others were of the heterogeneous HFE genotype. Among 1282 blood donors tested, the observed H63D, S65C and C282Y allele frequency were 12.8% (95% confidence interval (CI) 11.5-14.2%), 1.8% (95% CI 1.4-2.5%) and 3.6% (95% CI 3.0-4.5%), respectively. Approximately 33% of the tested subjects had at least one of the three HH mutations, and 1% of them were C282Y homozygotes or compound heterozygotes C282Y/H63D or C282Y/S65C, presenting an increased risk for iron overload disease. A significant variation in H63D allele frequency was observed for one of the Slovenian regions.

CONCLUSION

The improved real-time PCR assay for H63D, S65C and C282Y mutations detection is accurate, fast, cost-efficient and ready for routine screening and diagnostic procedures. The genotype frequencies in the Slovenian population agree with those reported for the Central European populations although some deviations where observed in comparison with other populations of Slavic origin. Regional distribution of the mutations should be considered when planning population screening.

An open population screening study for HFE gene major mutations proves the low prevalence of C282Y mutation in Central Italy

BACKGROUND

The C282Y mutation in the HFE gene is responsible for most cases of hereditary haemochromatosis.

AIM

To investigate the allele frequency of HFE mutations and the associations between mutations and cases of iron overload or liver diseases in an open population of Central Italy.

METHODS

A total of 502 individuals over 8 years of age, comprising 203 males and 299 females, who were residents in Arsita (a small town in Central Italy), were assayed for: C282Y, H63D and S65C mutations of the HFE gene by TaqMan probes; body mass index, serum ferritin, transferrin saturation, transaminases, GGT, glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, HBV and HCV serum markers. Information was obtained on alcohol intake. Liver ultrasound was performed in 334 (67%) subjects.

RESULTS

The allele frequencies for C282Y, H63D and S65C were 2%, 15%, and 0.01%, respectively. C282Y/wt was found in 19 subjects (4%), H63D/wt in 127 (25%), H63D/H63D in 11 (2%) and S65C/wt in one (2.0 per thousand). No homozygosity for C282Y or compound mutation (C282Y/H63D) was found in the study population, but 27 subjects (5%) had TfSat >45% (including 10 subjects with high serum ferritin). Overall, 49 subjects (9.8%) were HCV-RNA-positive. Logistic regression analysis indicated that male gender (P = 0.000) and hepatic steatosis (P = 0.017) were independent variables correlating to a high serum ferritin.

CONCLUSION

C282Y HFE mutation is less frequent in Central Italy than in Northern Italy.

Hereditary iron and copper deposition: diagnostics, pathogenesis and therapeutics

Hereditary deposition of iron (primary haemochromatosis) or copper (Wilson's disease) are autosomal recessive metabolic disease characterized by progressive liver pathology and subsequent involvement of various other organs. The prevalence of primary haemochromatosis is approximately 0.5%, about 200 times higher than the prevalence of Wilson's disease. The two diseases are characterized by homozygous occurrences of mutations in the HFE gene on chromosome 6 (primary haemochromatosis) and the ATP7B gene on chromosome 13 (Wilson's disease). Unlike most other inherited conditions, these diseases can be successfully treated, emphasizing the importance of early diagnosis. Serum ferritin values, transferrin saturation and genetic analysis are used when diagnosing haemochromatosis. The diagnostics of Wilson's disease depends on the use of urinary copper values, serum ceruloplasmin and liver biopsy. If untreated, both of these genetic diseases result in rapidly progressing multiorgan damage and early death. The key treatment for haemochromatosis is phlebotomy, for Wilson's disease chelation or Zn treatment. Although the present treatments considerably improve the prognosis of patients, they may be inadequate in patients diagnosed so late that extensive body deposits of metal have been developed. The main research needs in this field are to further clarify molecular mechanisms of disease progression and to develop new chelators that are more effective and less toxic than those presently available.

Status of HFE mutation in thalassemia syndromes in north India

Hereditary hemochromatosis is an autosomal recessive and most commonly inherited single gene disorder among Caucasians, with a prevalence of 5 per 1,000 and a carrier frequency of 1 in 10. Two point mutations were described and are referred as C282Y and H63D. In the present study, we have analyzed 729 north Indian samples for C282Y and H63D mutations. Of these, no allele of the C282Y mutation was seen, while 3 homozygous and 43 heterozygous for the H63D mutation were seen in the patients of thalassemia group. However, 47 cases were found heterozygous for the H63D mutation among the normal groups (11.16%).

Of mice and men: genetic determinants of iron status

Fe homeostasis is maintained by regulation of Fe absorption to balance largely unregulated body Fe losses. The majority of human subjects maintain relatively constant Fe stores; however, Fe deficiency and Fe overload are common conditions. Fe overload is frequently associated with mutations in genes of Fe metabolism. The present paper summarises present knowledge of these mutations as well as indicating other genes that animal studies have implicated as candidates for influencing body Fe stores.

Frequency of the hemochromatosis gene (HFE) 282C→Y, 63H→D, and 65S→C mutations in a general Mediterranean population from Tarragona, Spain

Three mutations have recently been detected in the hereditary hemochromatosis HFE gene (282C-->Y, 63H-->D, and 65S-->C). To determine their prevalence in a northeastern Spanish Mediterranean population, we studied 812 subjects between 18 and 75 years of age, randomly selected from the electoral roll of three villages. There were no homozygotes for the 282C-->Y or S65D mutations in this sample. For the 63H-->D mutation, 4.8% were homozygotes; 4.3, 32.3, and 2% were heterozygotes for the 282C-->Y, 63H-->D, and 65S-->C mutations, respectively. The prevalence of compound heterozygotes was 2% for 282C-->Y/63H-->D and 0.6% for 63H-->D /65S-->C. We found no significant differences between men and women. In conclusion, 46% of this Mediterranean population of Spain are carriers of at least one of the three mutations that can increase iron absorption.

Influence of gene polymorphisms in ulcer healing process after superficial venous surgery

OBJECTIVE

Role of superficial venous surgery in reducing the time it takes for ulcers to heal is still controversial, although all studies confirm a significant reduction in ulcer recurrences. Recently, the HFE-C282Y and FXIII-V34L gene variants demonstrated a role in the risk of venous ulceration in primary chronic venous disorder (CVD) and in modulating lesion size in chronic venous ulcer (CVU), respectively. This study was conducted to investigate the role of HFE-C282Y and FXIII (V34L and P564L) gene variants in ulcer healing time after superficial venous surgery, by assessing the outcome of a cohort of homogeneous CVU patients.

METHODS

The study selected 91 patients affected by primary CVU (CEAP C6, Ep, Asp, Pr), with the exclusion of any other comorbidity factor involved in delayed healing process, who underwent surgery. We assessed the ulcer area and the healing time. Patients were genotyped by polymerase chain reaction for FXIII (V34L and P564L) and for HFE-C282Y substitutions.

RESULTS

Globally, CVU cases had a postoperative mean healing time of 8.5 +/- 5.7 weeks. For the subset of cases above and below the median value (M = 8.0 weeks), FXIII-V34L genotype distribution significantly differed (P < .0001). In addition, Kaplan-Meier analysis yielded specific healing time profiles for the different FXIII-V34L classes of genotype (P = .00001), with an increased risk of delayed healing for the FXIII-VV genotype (hazard ratio, 4.14; 95% confidence interval, 2.1 to 8.2; P = .00005). Although FXIII-P54L genotype distributions did not differ, homozygous 564LL cases (P = .005) and double carriers for both FXIII variants (P < .0001), had a significantly reduced healing time vs wild types. No differences in healing time were observed between carriers and noncarriers of the HFE-C282Y variant, whereas when these cases were stratified by FXIII-V34L genotypes, the L34 carriers had a significantly shorter healing time, irrespective of the HFE genotype.

CONCLUSION

The FXIII-34L variant was significantly associated with shorter healing time after superficial venous surgery, suggesting a role in the healing and tissue regeneration phases. Conversely, HFE-C282Y, despite its role in ulcer establishment, did not affect the postoperative healing time. In perspective, the identification of patients with a poor prognosis may give clinicians the opportunity to modify management and to target tailored therapies in the view of a new and alternative concept of treatment based on pharmacogenomics.

Was the C282Y mutation an Irish Gaelic mutation that the Vikings help disseminate?

The C282Y mutation is held to have arisen in either a Celtic or a Viking ancestor some 60 generations ago. While the Scandinavians have a high frequency of C282Y, the Irish have the highest frequency of the C282Y mutation in the world. However testing of the Irish people for C282Y has been patchy. The true frequency of the C282Y mutation in Ireland and specifically in the relatively isolated western province of Connaught is unknown. Establishment of the C282Y frequency in the Irish male population of Connaught with traditional Irish surnames, a group which has a virtual fixation for Y chromosome R1b3, could help establish C282Y as an Irish mutation. Elucidation of greater C282Y haplotype diversity for the Irish as opposed to the Scandinavians would indicate the Irish as the likely source population for C282Y. Taken together, linking of C282Y to the Irish Gaelic male population of Connaught and establishment of an Irish origin of the C282Y mutation would point to dissemination of the C282Y mutation by Viking raiders and colonizers.

Iron prophylaxis in pregnancy--general or individual and in which dose?

Iron is mandatory for normal fetal development, including the brain. Iron deficiency may have deleterious effects for intelligence and behavioral development. It is important to prevent iron deficiency in the fetus by preventing iron deficiency in the pregnant woman. Iron deficiency anemia during pregnancy is a risk factor for preterm delivery and low birth weight. In the Western countries there is no consensus on iron prophylaxis to pregnant women. An adequate iron balance during pregnancy implies body iron reserves of >or=500 mg at conception. The physiologic iron requirements in the second half of gestation cannot be fulfilled solely through dietary iron. Iron supplements during gestation consistently increase serum ferritin and hemoglobin and reduce the prevalence of iron deficiency anemia. Iron has a negative influence on absorption of other divalent metals and increases oxidative stress in pregnancy, for which reason minimum effective iron dose should be advised. From a physiologic point of view, individual iron prophylaxis according to serum ferritin concentration should be preferred to general prophylaxis. Suggested guidelines are (1) ferritin>70 microg/l: no iron supplements; (2) ferritin 30-70 microg/l: 40 mg ferrous iron daily; and (3) ferritin<30 microg/l: 80-100 mg ferrous iron daily. In controlled studies, there are no documented side effects of iron supplements below 100 mg/day. Iron supplements should be taken at bedtime or between meals to ensure optimum absorption.

The overlapping of local iron overload and HFE mutation in venous leg ulcer pathogenesis

Chronic venous stasis determines red blood cell extravasation and either dermal hemosiderin deposits or iron-laden phagocytes. Several authors have suspected that iron could play a role in the pathogenesis of venous leg ulcers. They hypothesized that local iron overload could generate free radicals or activate a proteolytic hyperactivity on the part of metalloproteinases (MMPs) or else down-regulate tissue inhibitors of MMPs. However, they were unable to explain why iron deposits, visible in the legs of patients with chronic venous disease (CVD), cause lesions in only some individuals, whereas in others they do not. We hypothesized that such individual differences could be genetically determined and investigated the role of the C282Y and H63D mutations of the HFE gene. C282Y mutation significantly increases the risk of ulcer in primary CVD more than six times (OR = 6.69; 1.45-30.8; p = 0.01). Patients carrying the H63D variant have an earlier age of ulcer onset, by almost 10 years (p > 0.004). The increased risk of skin lesion and the early age of onset of the disease in HFE carriers confirm in a clinical setting that intracellular iron deposits of mutated macrophages have less stability than those of the wild type. We hypothesize that the physiologic iron protective mechanisms are affected by the HFE mutations and should be investigated in all diseases characterized by the combination of iron overload and inflammation.