H63D Heterozygotes Research Articles

Risk of Hepatocellular Carcinoma in Patients with Various HFE Genotypes.

Hereditary hemochromatosis (HH) is associated with increased risk of hepatocellular carcinoma (HCC). However, HCC risk factors within this population and across various HFE genotypes remain unclear. We conducted a retrospective cohort study of patients with ≥ 1 HFE genotype test in the Veterans Health Administration. We followed patients until HCC, death, or 6/30/19. We calculated incidence rates (IRs) and used Cox proportional hazards models to estimate HCC risk. In patients with type-1 HH genotypes (C282Y/C282Y or C282Y/H63D), we examined risk factors for HCC. We identified 5225 patients: 260 were C282Y/C282Y; 227 were C282Y/H63D; 436 were H63D heterozygous; 535 had other HFE mutations; 3767 without mutation. IR for C282Y/C282Y homozygotes (5.59/1000 PYs) and C282Y/H63D compound heterozygotes (4.12/1000 PYs) were significantly higher than controls (0.92/1000 PYs) with adjusted hazard ratio (adj HR), 95% CI 8.80, 4.17-18.54; and 5.25, 2.24-12.32, respectively. HCC risk was higher in H63D heterozygote than controls (adj HR = 2.82, 95% CI 1.21-6.58); cases were related to non-alcoholic fatty liver disease. Among patients with HH, age ≥ 65 (adj HR = 2.2, 95% CI 0.47-10.27), diabetes (adj HR 3.74, 95% CI 1.25-11.20) and high baseline aspartate-aminotransferase to platelet ratio-index (APRI, adj HR = 3.91, 95% CI 1.29-11.89) had higher risk. Among patients with high baseline ferritin, persistent ferritin > 250ng/mL had higher risk. HCC risk was high in C282Y homozygous and C282Y/H63D patients. These HFE genotypes, older age, diabetes, high APRI/ferritin levels were associated with increased risk. While H63D heterozygous genotype was associated with HCC risk, this association might be due to metabolic factors.

Evaluating the Volumetric Liver Fat Fraction in Patients Referred for Investigation of Hyperferritinemia

Introduction Elevated serum ferritin (hyperferritinemia, HF) can result from increased iron load, increased inflammation or from liver damage. In the most common forms of hereditary hemochromatosis (HH), elevated ferritin is usually seen with elevated transferrin saturations, [1,2]. In patients with HF but without raised liver iron concentration (LIC, mg/g dry wt [dw]), increased liver fat (hepatic steatosis, HS), either in isolation or as part of a metabolic syndrome, needs to be considered. HS is important to identify as it may progress to chronic liver damage and is potentially reversible with lifestyle interventions. Hepatic fat can now be quantified with magnetic resonance imaging (Hepafat-Scan®)[3]. Here, we evaluate the usefulness of this method in the diagnosis and subsequent management of patients referred with HF. Methods A total of 132 patients (median age 48 years, range 21-86 ; female: male ratio 1:2.5) referred for investigation of HF and who underwent estimation of liver iron concentration (LIC) by R2-MRI (FerriScan®) over a four-year period (January 2015 - December 2018) are included in this analysis. Data on patient demographics, presenting serum ferritin (SF) and transferrin saturation were obtained. Genetic testing for C282Y and H63D was also performed. Genetic testing for rarer forms of haemochromatosis was confined to patients with unexplained raised LIC. Patients with iron overload secondary to chronic iron ingestion or blood transfusion were excluded from this analysis. Results Patients were subdivided by genetic diagnosis: C282Y homozygote (26, 19.7%), C282Y/H63D (18, 13.6%), H63D homozygote (10, 7.6%), C282Y heterozygote (8, 6.1%), H63D heterozygote (18, 13.6%), autosomal dominant ferroportin disease (4, 3%) and negative HFE gene testing (48, 36.4%). There was no statistical difference between mean presenting SF (p= 0.307) between the different groups. C282Y homozygotes, and those with autosomal ferroportin disease had a significantly higher LIC than others (p<0.001). C282Y homozygotes and compound heterozygotes had a significantly higher transferrin saturation than other groups (p<0.001). SF positively correlated with LIC (p<0.001). After genetic testing and LIC quantification, 32 patients underwent a HepaFat-Scan®. Median age was 63 years, range 23 - 74 years; female: male ratio 1:3.5. 54.5% had a volumetric liver fat fraction (VLFF) > 5%. 7.4% of patients, who did not undergo Hepafat-Scan®, had HS based on sonographic findings. Patients with definitive evidence of HS as defined by VLFF >5% had mean LIC of 1.36mg/g dw, and a higher mean presenting SF of 926 µg/L than those with HS <5% (NS, p= 0.47). Those with VLFF <5% had a mean presenting SF of 783 mg/ml and mean LIC of 2.2 mg/g dw. In patients with LIC ≤3mg/g dw (n= 91, mean 1.6), mean presenting SF was 728 mg/ml. 28 of these patients went onto have a Hepafat-Scan®, 16 of which (57.1%) had confirmed steatosis with VLFF >5%. In patients with LIC >3mg/g dw (n= 41, mean LIC 6.9), mean presenting SF was significantly higher at 1056 mg/ml (p=0.021). 4 patients with LIC >3mg/g dw also had a Hepafat-Scan®, with 1 patient having VLFF >5%. Patients with confirmed steatosis were referred for specialist hepatology consultation. Conclusion In patients referred for investigation of HF, demonstrable steatosis (VLFF >5%) by Hepafat-Scan® is remarkably high (13.3% of all referred patients and 54% of patients who received Hepafat-Scan®). The Hepafat-Scan® data show that HS is generally confined to patients with low LIC (≤3mg/g dw) (Figure 1) reflecting the selective decision pathway adopted of excluding hepatic siderosis before proceeding to Hepafat-Scan®. SF is significantly higher in non-iron overloaded patients with HS (VLFF >5%) than those without HS (Figure 1). Estimation of HS should be considered in the diagnostic pathway of patients referred for investigation of HF, particularly when LIC values are not found to be meaningfully increased.

Double red blood cell donors with increased ferritin levels: a descriptive study.

One of the measures proposed to mitigate iron loss in blood donors is monitoring of their ferritin levels. Occasionally, high ferritin levels are found in monitored donors. We report the results of the clinical and laboratory investigation of 80 double red blood cell (DRBC) donors with high ferritin levels. All DRBC donors' ferritin levels were measured during each visit for a donation. Donors with high ferritin levels who agreed to participate underwent a clinical and laboratory evaluation. A total of 165 of 2757 DRBC donors had at least one high ferritin level. Five were already known to suffer from hemochromatosis. A full investigation was available for 80 other donors. A total of 61 of 80 donors had normalized their ferritin level at the time of their laboratory evaluation. Only 16 donors had high serum iron levels, of whom four had increased saturation index. Genetic analysis gave the following results: C282Y homozygous, two; H63D homozygous, six; C282Y/HC3D double heterozygote, six; C282Y heterozygote, six; H63D heterozygote, 19; and no mutations, 39. None of the other laboratory investigations contributed data explaining the high ferritin levels observed. In most donors with high ferritin levels, the phenomenon was transient, with normal ferritin levels found in follow-up. Less than 10% of these donors had evidence of iron overload. Only eight were homozygous for mutations associated with hemochromatosis. An extensive laboratory investigation by the treating physician should only be recommended in donors with persistently high ferritin levels.

A novel homozygous stop-codon mutation in human HFE responsible for nonsense-mediated mRNA decay.

HFE-hemochromatosis (HH) is an autosomal disease characterized by excessive iron absorption. Homozygotes for H63D variant, and still less H63D heterozygotes, generally do not express HH phenotype. The data collected in our previous study in the province of Matera (Basilicata, Italy) underlined that some H63D carriers showed altered iron metabolism, without additional factors. In this study, we selected a cohort of 10/22 H63D carriers with severe biochemical iron overload (BIO). Additional analysis was performed for studying HFE exons, exon-intron boundaries, and untranslated regions (UTRs) by performing DNA extraction, PCR amplification and sequencing. The results showed a novel substitution (NM_000410.3:c.847C>T) in a patient exon 4 (GenBankJQ478433); it introduces a premature stop-codon (PTC). RNA extraction and reverse-transcription were also performed. Quantitative real-time PCR was carried out for verifying if our aberrant mRNA is targeted for nonsense-mediated mRNA decay (NMD); we observed that patient HFE mRNA was expressed much less than calibrator, suggesting that the mutated HFE protein cannot play its role in iron metabolism regulation, resulting in proband BIO. Our finding is the first evidence of a variation responsible for a PTC in iron cycle genes. The genotype-phenotype correlation observed in our cases could be related to the additional mutation.

AUDIT OF THE APPROPRIATENESS OF HEPATOMA SURVEILLANCE IN A COHORT OF PATIENTS ATTENDING A DEDICATED HAEMOCHROMATOSIS CLINIC

IntroductionHereditary Haemochromatosis (HH) remains the commonest genetic disorder in populations of northern European origin with a prevalence of 1 per 220–250.1 The HH service in Tallaght hospital is an expanding...

Clinical impact of HFE mutations in Japanese patients with chronic hepatitis C

HFE mutations, a common cause of hereditary hemochromatosis (HH), are reportedly associated with hepatic iron overload, severe liver fibrosis, and good response to interferon treatment in European patients with chronic hepatitis C (CHC). HH shows ethnicity-based differences and little is known about the effects of HH mutations on CHC in the Japanese. Thus, the aim of this study was to clarify the clinical influence of HFE mutations in Japanese CHC patients. In a total of 251 patients with CHC, we analyzed the frequencies of H63D and S65C mutations in the HFE gene, and the influence of these mutations on clinical parameters and response to pegylated-interferon-alpha 2b (PEG-IFN) plus ribavirin therapy. Fourteen patients (5.6%) carried the H63D mutation; all were heterozygotes. No S65C mutations were found. Only hemoglobin levels in the H63D heterozygotes were higher than in wild-type patients. Eleven of 14 H63D heterozygotes achieved sustained virological response (SVR). On univariate analysis, factors associated with SVR were interleukin 28B (IL28B) polymorphism, age, hepatitis C virus (HCV) genotype, HCV viral load, white blood cell count, stage of fibrosis and H63D mutation. All patients with both TT genotype in IL28B (rs8099917) and H63D mutation in HFE (n = 10) achieved SVR. The H63D mutation has little impact on the clinical characteristics of CHC, but is related to favorable response to PEG-IFN plus ribavirin therapy, particularly in patients with the TT allele in IL28B.

HFE gene mutations in patients with alcoholic liver disease. A prospective study from northwestern Poland

Hereditary hemochromatosis has been linked with C282Y and H63D mutations of the HFE gene encoding human hemochromatosis protein. It is genetic disorder of iron metabolism, leading to iron accumulation and increased liver fibrosis. The association between alcoholic liver disease (ALD) and HFE gene mutations remains unclear and requires clarification. The aim of the study was to determine the prevalence of C282Y and H63D mutations in patients with ALD and healthy individuals and to analyze laboratory data in the context of HFE gene mutation in ALD patients. We analyzed 119 patients with ALD. The control group comprised 1516 DNA samples obtained either from cord blood or healthy subjects from the records of general practitioners. HFE mutations were detected using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Among the ALD patients, 0.84% were homozygous and 3.36% were heterozygous for the C282Y mutation, while 5.04% were homozygous and 21.85% heterozygous for the H63D mutation. There was 1 C282Y/H63D compound heterozygote in the ALD group. In the control group, 2 homozygotes and 117 heterozygotes for the C282Y mutation were identified. As for the H63D mutation, 2.5% homozygotes, 25% heterozygotes, and 1.4% compound heterozygotes were found. There was a trend towards a more common occurrence of ALD patients homozygous for the H63D mutation. Patients with H63D genotype had higher total and low-density lipoprotein cholesterol. The prevalence of HFE mutations in ALD patients is similar to that observed in healthy subjects and comparable to the prevalence in other Central European countries. Our findings on lipid disturbances in the H63D heterozygotes are potentially interesting and require further studies on larger patient groups.

Effects of C282Y, H63D, and S65C HFE gene mutations, diet, and life-style factors on iron status in a general Mediterranean population from Tarragona, Spain

Mutations in the HFE gene result in iron overload and can produce hereditary hemochromatosis (HH), a disorder of iron metabolism characterized by increased intestinal iron absorption. Dietary quality, alcoholism and other life-style factors can increase the risk of iron overload, especially among genetically at risk populations. Polymorphisms of the HFE gene (C282Y, H63D and S65C) were measured together with serum ferritin (SF), transferrin saturation (TS) and hemoglobin, to measure iron status, in randomly-selected healthy subjects living in the Spanish Mediterranean coast (n = 815; 425 females, 390 males), 18 to 75 years of age. The intake of dietary components that affect iron absorption was calculated from 3-day dietary records. The presence of C282Y/H63D compound heterozygote that had a prevalence of 2.8% in males and 1.2% in females was associated with an elevated TS and SF. No subject was homozygous for C282Y or S65C. The C282Y heterozygote, H63D heterozygote and homozygote and H63D/S65C compound heterozygote genotypes were associated with increased TS relative to the wild type in the general population. These genotypes together with the alcohol and iron intake increase the indicators of iron status, while calcium intake decreases them. We did not observe any affect of the S65C heterozygote genotype on these levels. All the HFE genotypes except for the S65C heterozygote together with the alcohol, iron and calcium intake affect the indicators of iron status. The C282Y/H63D compound heterozygote genotype has the higher phenotypic expression in our Spanish Mediterranean population.

Population‐based study of cystic fibrosis disease severity and haemochromatosis gene mutations

Haemochromatosis (HFE) mutations increase the risk of bowel obstruction in cystic fibrosis (CF), but the impact on other disease manifestations is unknown. We determined the prevalence of HFE mutations (C282Y and H63D) in the Tasmanian CF population and assessed the relationship to systemic iron stores, Pseudomonas aeruginosa infection, lung disease severity and prevalence of diabetes. DNA was obtained from 82 individuals (96% of the entire CF population); 19 (23.2%) were H63D heterozygotes, three (3.7%) were H63D homozygotes and two patients were compound C282Y/H63D (2.4%). Seven (8.5%) patients were heterozygous for the C282Y mutation. Overall, 31 (37.8%) patients carried a HFE mutation. CF patients possessing HFE mutations had significantly better iron stores than non-carriers (P < 0.05). The mean slopes of annual decline in FEV1 and FVC % predicted were significantly steeper in HFE carriers compared with non-carriers (P < 0.01). Patients with HFE mutations were more likely to have had childhood bowel obstruction (RR 2.44, 95% CI: 1.04-5.74, P < 0.05). Diabetes was more common in HFE carriers (RR 2.96, 95% CI: 0.99-8.8, P = 0.05), but this effect attenuated when corrected for age (RR 2.89, 95% CI: 0.91-9.21, P = 0.07). HFE gene mutations modify disease severity in CF, through probable effects on iron homeostasis.

Hemochromatosis gene mutations and treatment of anemia in patients on hemodialysis

Hemochromatosis causes iron overload by enhanced intestinal absorption. This study examined erythropoietin and intravenous (i.v.) iron requirements in hemodialysis (HD) patients with HFE mutations. Patients on HD for > 90 days with no cause of anemia except chronic kidney disease were tested for HFE mutations (H63D and C282Y). Intravenous iron and erythropoietin doses were adjusted to achieve recommended targets. Monthly hemoglobin (Hb), ferritin, mean corpuscular volume, mean cell hemoglobin, erythropoietin, and i.v. iron doses for 3 consecutive months were averaged. Of 172 patients, 71 (41.3%) had > or = 1 HFE mutation: 24 (14%) C282Y heterozygotes, 40 (23.3%) H63D heterozygotes, 5 compound heterozygotes, and 2 homozygotes. Comparing patients with > or = 1 HFE mutation to those without mutations showed no significant difference in Hb or serum ferritin. There was a trend toward lower median weekly erythropoietin dose in patients with > or = 1 HFE mutation (94.0 vs. 135.4 U/kg body weight; P=0.13). There was no difference in median weekly i.v. iron dose (1.0 vs. 0.9 mg/kg body weight; P=0.56). Comparing the 30 patients with a C282Y mutation to patients without HFE mutations produced similar results. Comparing the 47 patients with an H63D mutation, with those without HFE mutations, no discernable trend was observed. In this study, patients with HFE gene mutations on HD for established renal failure do not require less iron supplementation to achieve recommended Hb targets. We observed a trend toward lower erythropoietin requirement in patients possessing C282Y mutations. Larger studies may clarify the role of HFE mutations, regulators of iron metabolism and erythropoiesis in chronic kidney disease.

Hepatic Iron, Serum Ferritin, HFE Mutation, and Hepatic Fibrosis in Chronic Hepatitis C

Objectives: We studied the status of hepatic iron deposition and its relationship with blood iron indices, liver histology, and HFE gene mutations in Korean patients with chronic hepatitis C (CH-C). Methods: 105 patients with CH-C who underwent pretreatment liver biopsy were consecutively enrolled. The hepatic iron deposition, histological activity and fibrosis were assessed by appropriate pathological scoring systems, clinical data including serum iron indices, and HFE gene mutation. Results: Hepatic iron deposition was found in 37 patients (35%), which was not significantly associated with degree of hepatic fibrosis or steatosis. The serum ferritin level was elevated in 27% of the patients and was an independent factor associated with hepatic iron deposition by logistic regression; however, it was not significantly associated with hepatic fibrosis either. Only H63D heterozygote was found in 6 out of 48 patients (12.5%), which was not different from the prevalence of H63D mutation in the Korean population (8.5%). Conclusions: Hepatic iron deposition was uncommon and mild in Korean CH-C. Neither hepatic iron deposition nor serum ferritin were significantly related to the severity of hepatic fibrosis, which does not support the significant role of iron in the progression of hepatic fibrosis.

HFE Gene Mutations, Serum Ferritin Level, Transferrin Saturation, and Their Clinical Correlates in a Korean Population

The aim of this study was to investigate HFE gene mutations, blood iron indices, and their clinical correlates in a Korean population. In 484 prospectively enrolled health-check examinees, HFE gene mutations and iron indices with clinical and laboratory variables were analyzed. Although neither the C282Y nor S65C gene mutation were found, the H63D heterozygote was detected in 41 subjects (8.5%). The mean serum ferritin and transferrin saturation (TS) were 136.2 +/- 129.8 microg/dl and 39.2 +/- 15.7%, respectively. The H63D genotype was not significantly associated with iron indices. High serum ferritin was associated with old age, the male gender, high body mass index (BMI), and the presence of nonalcoholic fatty liver disease (NAFLD). High TS was associated with the male gender and alcohol drinking. HFE gene mutation is rare; however, TS seems to be higher in Koreans compared to Caucasians or other ethnic groups. Serum ferritin reflects iron store as well as the presence of NAFLD.

Frequency of the HFE C282Y and H63D polymorphisms in Brazilian malaria patients and blood donors from the Amazon region

Malaria is an endemic parasitosis and its causitive agent, Plasmodium, has a metabolism linked to iron supply. HFE is a gene with the polymorphisms C282Y and H63D, which are associated with a progressive iron accumulation in the organism leading to a disease called hereditary hemochromatosis. The aim of the present study was to determine the allelic and genotypic frequencies of the HFE gene polymorphisms in malaria patients and blood donors from the Brazilian Amazon region. We screened 400 blood donors and 400 malaria patients for the HFE C282Y and H63D polymorphisms from four states of the Brazilian Amazon region by polymerase chain reaction and restriction fragment length polymorphism analysis. We did not find any C282Y homozygous individuals, and the only five heterozygous individuals detected were from Pará State. The most frequent genotype in the North region of Brazil was the H63D heterozygote, in both study groups. Our results contribute to the concept that the Brazilian Amazon region should not be regarded as a single entity in South America. These polymorphisms did not influence the symptoms of malaria in the population studied, as neither severe signs nor high parasitemia were observed. Therefore, different hereditary hemochromatosis diagnostic and control measures must be developed and applied within its diverse locations. Investigations are currently being carried out in our laboratory in order to determine the importance of the coexistence of hereditary hemochromatosis in patients affected by parasitic diseases, such as malaria.

Analysis of the HFE gene (C282Y, H63D and S65C) mutations in a general Chinese Han population

Hereditary hemochromatosis (HH) is one of the most common autosomal recessive genetic disorders of iron metabolism in white populations, which leads to inappropriately high iron absorption. C282Y, H63D, and S65C are three major missense mutations of the hemochromatosis gene (HFE). In the present study, C282Y, H63D, and S65C mutations in 395 normal Chinese Han populations from Zhejiang province were investigated. No C282Y, S65C mutations, and H63D homozygote was observed, while the genotype frequency of H63D heterozygote was 4.6% and the allelic frequency 2.3% in this population. This was the first report to analyze the prevalence of C282Y, H63D, and S65C mutations in the HFE gene in a Chinese Han population. Low incidence of the HFE gene mutations could be a reason for the rarity of HH in the Chinese Han population studied.

HFE Gene Mutation, Chronic Liver Disease, and Iron Overload In Turkey

We aimed to determine the relationships between iron overload and HFE gene mutation in chronic liver disease in Turkey. One hundred thirteen chronic liver disease patients and 138 healthy controls were evaluated regarding their clinical, biochemical, and genetic parameters. Each group was divided into two subgroups according to transferrin saturation (TS) (45% and >45%). HFE gene mutation was analyzed by the PCR-RFLP method. C282Y homozygote, heterozygote, and wild-type mutation rates were 1.7%, 0%, and 98.3% in patients and 0%, 1.4%, and 98.6% in controls, respectively. H63D homozygote, heterozygote, and wild-type mutation rates were 1.8%, 24.7%, and 73.5% in patients and 1.4%, 24%, and 74.6% in controls, respectively. Mutation rates were not statistically different in patients with high and normal TS. Iron overload was positively correlated with biochemical activity and Child-Pugh score (P < 0.05). In multivariate analysis, H63D homozygotic mutation was an independent factor for the development of hepatocellular carcinoma (P = 0.004). We conclude that C282Y mutation is very rare in Turkey. Iron overload is not related to H63D mutation but is positively correlated with biochemical activity and Child-Pugh score in chronic liver diseases.

The Association Between H63D Mutations in HFE and Amyotrophic Lateral Sclerosis in a Dutch Population

Mutations in HFE, a gene defect that can disrupt iron metabolism, have been implicated in increasing the risk of developing amyotrophic lateral sclerosis (ALS). To further establish the association between ALS and HFE mutations by investigating whether HFE mutations are associated with an increased risk of developing ALS in a population in The Netherlands and by pooling our results with those from previous studies. Retrospective study. Tertiary referral center for neuromuscular disorders. Genotyping for 2 common HFE mutations was performed in 289 patients with ALS and 5886 population-based controls in The Netherlands between January 1, 2000, and December 31, 2004. Development of ALS and clinical phenotype were compared among the different HFE genotypes, adjusting for known prognostic factors such as age at onset and sex. Homozygosity for H63D was associated with an increased risk of developing ALS (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.1-4.1). After pooling our results with those from previous studies, a positive association between H63D homozygotes (OR, 2.7; 95% CI, 1.7-4.4), heterozygotes (OR, 1.5; 95% CI, 1.0-2.1), and mutation carriers (OR, 1.7; 95% CI, 1.1-2.5) was found. Within the patient group, heterozygosity for the H63D mutation was associated with a higher age at onset. These findings suggest that H63D mutations in HFE play a role in the pathogenesis of ALS in various populations. This association might involve a later-onset subset of ALS.

The Clinical Relevance of Compound Heterozygosity for the C282Y and H63D Substitutions in Hemochromatosis

Two major mutations are defined within the hemochromatosis gene, HFE. Although the effects of the C282Y substitution have been well characterized, the clinical significance of the C282Y/H63D state remains unclear. This study assessed the phenotypic expression in C282Y/H63D subjects as compared with C282Y homozygotes. Data were obtained from 91 C282Y/H63D probands, 158 C282Y/H63D subjects identified through family screening, and 483 C282Y homozygotes. Subjects underwent clinical evaluation, genotyping, biochemical assessment, and liver biopsy examination where clinically indicated. C282Y/H63D probands had significantly less clinical and biochemical expression than C282Y homozygotes. Biochemical expression was higher in C282Y/H63D probands than in C282Y/H63D subjects identified through family screening (P < .001). Of the C282Y/H63D subjects with serum ferritin levels greater than 1000 mug/L, all had known comorbid factors that could have contributed to the increased ferritin level. Of the 51 C282Y/H63D subjects who underwent liver biopsy examination, significantly increased iron stores were present in 9 subjects and hepatic fibrosis was present in 13. Twelve of the 13 had evidence of hepatic steatosis, excess alcohol consumption, or diabetes. The mobilizable iron level was significantly higher in C282Y homozygous males than in compound heterozygous males (P < .001). Genetic screening of C282Y/H63D first-degree relatives detected 5 C282Y homozygotes. C282Y/H63D subjects referred for assessment had a high prevalence of increased iron indices but did not develop progressive clinical disease without comorbid factors such as steatosis, diabetes, or excess alcohol consumption. When fibrosis was seen, 1 or more comorbid factors almost always were present. Thus, phlebotomy therapy is warranted and cascade screening of relatives should be performed because expressing C282Y homozygotes may be detected.

Genotype–phenotype correlation in a Spanish population homozygous for the H63D mutation of the HFE gene

Hereditary hemochromatosis (HH) is an autosomal recessive disorder of iron metabolism with excessive cellular iron levels resulting in tissue damage [1–3]. In 1996, Feder et al. showed that in most HH patients, the HFE gene is mutated in position 282 (replacement of cysteine by tyrosine, C282Y) [4]. In Spain, 85–90% of HH patients showed this mutation [5, 6]. However, a second mutation, the replacement of histidine in position 63 by aspartic acid (H63D), is much more frequent. In our area, the Northeast of Spain, the H63D mutation was present in 37% of the general population, and 4% were homozygous [7]. In a murine model, the contribution of the H63D homozygosity (DD genotype) was demonstrated. However, the iron overload (IO) was below that of the C282Y homozygosity (YY genotype) [8]. Moreover, data in humans support that the DD genotype could result in IO [9–11]. Given the high prevalence of this mutation in our population, we evaluated the genotype–phenotype correlation in homozygotes for the H63D mutation. Two studies were conducted in two Spanish populations. First, the correlation between the HFE mutations and the amount of iron in the liver was evaluated in 78 cases (7 cases were DD homozygotes) [12]. Liver biopsy was carried out because of a biochemical IO [serum transferrin saturation >50% and/or serum ferritin >350 μg/l]. Hemochromatosis was considered when the hepatic iron index (HII) exceeded 1.9 μmol/g of dry weight multiplied by the age in years, μmol/g.year [1–3]. In 30 out of 78 cases, HII exceeded 1.9 μmol/g.year, including three cases (10%) homozygous for the H63D mutation (HII=4.2, 3.9, and 3.8 μmol/g.year). Moreover, in one patient homozygous for the H63D mutation, the HII was 1.8 μmol/g.year Therefore, four out of the seven DD homozygotes showed moderate liver IOs (57%). C282Y homozygotes showed the highest levels of HII. DD homozygotes had higher levels of HII than wild-type patients and H63D heterozygotes (Table 1). The second study was conducted between 1998 and 2004 in 55 consecutive patients with the DD genotype. All patients came from our university hospital and were studied for all the known secondary causes of biochemical IO [13, 14]. Data were not available in one case, which was excluded from the study. Hepcidin (HAMP) gene mutations were investigated given that these mutations could modify the severity of the IO [15]. Transferrin saturation and serum ferritin were evaluated by automated methodologies (Hitachi 911 and Elecsys, Roche). Moreover, total iron removed by phlebotomy was calculated in grams. Mutations of the HFE gene (C282Y, H63D, and S65C) were analyzed with LightCycler equipment [6, 7, 14]. The HAMP gene was evaluated using single strand conformational polymorphism and direct sequencing [15]. The patients were 36 men and 18 women, with a median age was 51 years. They were chosen for the study because of a biochemical IO (41 cases) or a family study (13 cases). Forty-five patients (83%) showed a biochemical IO pattern. An underlying cause of biochemical IO was observed in 35 A. F. Remacha (*) . M. P. Sarda . M. J. Barcelo . V. Bach . A. Altes . M. Baiget . C. Guarner . I. Blesa Hematology Department, Hospital de Sant Pau, Avda Padre Claret 167, Barcelona, 0825, Spain e-mail: aremacha@hsp.santpau.es

Unexplained Serum Ferritin Elevations in Primary Care Patients with Elevated Serum Ferritin Concentrations and High Normal Transferrin Saturations.

Non-HFE primary iron overload exists in African Americans and other ethnic groups, but the prevalence and spectrum of clinical manifestations are not known. In the HEIRS (Hereditary Hemochromatosis and Iron Overload Screening) Study, participants were considered for further evaluation if the serum ferritin concentration was elevated and the transferrin saturation was more than 45% for women or 50% for men. We hypothesized that these screening criteria would miss a substantial number of African Americans and members of other ethnic groups with increased iron stores. In the process of screening 21,231 predominantly African-American and Hispanic primary care patients at the Howard University field center of the HEIRS Study, we identified 161 non-HFE-C282Y homozygotes ≥ 25 years of age with serum ferritin concentrations above the 97.5 percentile for the population (>700 ng/ml for men and >500 ng/ml for women) but transferrin saturations in the upper part of the normal range (35–50% for men and 30–45% for women). Of the 123 participants we were able to contact, 68 (55%) participated in a clinical evaluation, including 64 African Americans, three Hispanics and one Asian American with a mean ± SD age of 57 ± 13 years. Thirty-eight (56%) were females, 6 (9%) were HFE H63D heterozygotes and 2 (3%) were C282Y heterozygotes. Seven patients (10%) had normal serum ferritin concentration on repeat testing while 42 (62%) had potential reasons for elevated serum ferritin concentration other than a primary increase in body iron including (sequentially) multiple blood transfusions (>10 lifetime; n = 4), abnormal liver function tests (hepatitis C positive or AST >60 IU/L and AST>ALT; n = 17), hemoglobin < 10 g/dL men or 9 g/dL women (n = 1), elevated C-reactive protein with transferrin saturation not elevated (n = 17), and excessive alcohol use (n = 3). Nineteen patients did not have these explanations for increased serum ferritin concentration and were considered to have a possible primary iron-loading process (see Table).One of the patients with unexplained elevated serum ferritin concentration (an African American) had a diagnostic liver biopsy showing 2-3+ hepatocellular iron and heavy iron deposition in Kupffer cells and is on phlebotomy therapy; the others have been advised to have diagnostic liver biopsy or quantitative phlebotomy. We conclude that there are substantial numbers of African Americans with elevated serum ferritin concentration and normal transferrin saturation who have transfusional iron overload or a probable primary increase in body iron stores.Characteristics of 19 Patients with Unexplained Serum Ferritin ElevationsNo. (%) of Women8 (42)Age inyears (mean ± SD)63 ± 14Race (African American:Hispanic:Asian)16:2:1Hemoglobin in g.dL (mean ± SD) Men13.8 ±1.5Hemoglobin in g.dL (mean ± SD) Women12.9 ± 0.8HFE mutations in no. (%) C282Y heterozygotes0 (0)HFE mutations in no. (%) H63D heterozygotes2 (11)Ferritin category in no. (%) < 500 ng/ml7 (37)Ferritin category in no. (%) 500–1000 ng/ml9(57)Ferritin category in no. (%) 1000 ng/ml>3 (16)

HFE Genotype Modifies the Influence of Heme Iron Intake on Iron Status

Public health policy to prevent iron deficiency through food fortification or other measures may be disadvantageous to people with hereditary hemochromatosis. From a cohort of U.K. women, 2531 women were typed for C282Y and H63D mutations in the hemochromatosis gene. These women completed food frequency questionnaires and provided blood for iron status. C282Y homozygotes (n=31) had serum ferritin concentrations 2.4 times higher (95% confidence interval=1.9-3.1) than wild types (n=1774), but heterozygotes (n=726) were not different from wild types. H63D genotype had no effect on its own. The effect of heme iron intake (from meat, fish, and poultry) was 2.0 times greater (1.2-3.2) on C282Y homozygotes than other groups. Nonheme iron had little effect. There may be scope for dietary intervention in women homozygous for the C282Y mutation. C282Y heterozygotes and H63D homozygotes and heterozygotes have similar serum ferritin concentrations to wild type and need not reduce their meat intake other than as part of a normal healthy diet.