Screening for iron overload in the Turkish population

Survey of Hfe Gene C282Y Mutation in Turkish Beta-Thalassemia Patients and Healthy Population: A Preliminary Study

Objective: This study was planned in order to determine the effect of C282Y mutation in development of secondary hemochromatosis in beta-thalassemia patients and to determine the prevalence and allele frequency of this mutation in a healthy control group.

Materials and Methods: Eighty-seven children and young adults (46 males and 41 females; mean age: 15.6±6.1 years, range: 3-30 years) with beta-thalassemia major (BTM) and 13 beta-thalassemia intermedia (BTI) patients (6 males and 7 females; mean age: 19.6±3.5 years, range: 13-26 years) were included in the study. The control group comprised 100 healthy blood donors.

Results: Neither heterozygous nor homozygous HFE gene C282Y mutation was detected in patients with BTM or BTI, or in control group.

Conclusion: The C282Y mutation, which is supposed to be responsible for the majority of hereditary hemochromatosis, was not found to have a role in the development of hemochromatosis in beta-thalassemia patients and was not detected in a healthy Turkish population. However, research on larger cohorts of individuals is required in order to determine the exact prevalence of the HFE gene mutation in Turkish populations from diverse ethnic origins and whether it would have an impact on iron loading in thalassemic populations.

The prognostic role of hemochromatosis H63D allele in allogeneic hematopoietic stem cell transplantation

Iron overload is considered as a significant cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients. The presence of hemochromatosis gene (HFE) mutations might exacerbate iron toxicity in the post-transplant setting. This prospective study was planned to evaluate the genetic spectrum of HFE mutations in Turkish patients undergoing HSCT and the impact of HFE genotype on transplant morbidity and mortality. HFE genotypes of 102 patients [median age, 27.5 years (16-64 years); male/female, 73:29], who underwent allogeneic HSCT, were analyzed. Twenty-two patients were heterozygous and 1 patient was homozygous for the H63D mutation, while the C282Y mutation was observed in none of our patients. The frequency of invasive fungal infections (IFI) was significantly higher in H63D-mutated patients (p=0.004). H63D mutation was identified as an independent risk factor for the development of IFI (p=0.006, OR=0.554, SE=0.208), without an impact on overall survival and transplant-related mortality. The multifactorial iron-overloaded state in HSCT recipients might affect the phenotypic expression of HFE mutations and alter the severity of clinical presentation. The impact of HFE genotype on iron parameters and transplant-related morbidity and mortality should be validated with further studies.

Should we screen for hereditary hemochromatosis in healthy Lebanese: a pilot study

Hereditary hemochromatosis (HHC) is a genetic disorder of iron metabolism characterized by abnormal accumulation of iron that may lead to organ damage and death. Diagnosis is usually based on various genetic and phenotypic criteria. The study goals were to perform mutation analysis for 18 different mutations associated with HHC in healthy Lebanese, determine their allele frequency, and compare iron-overload status in identified carriers versus those found to be wild-type for mutations analyzed. 116 healthy adults (59 males and 57 females) underwent DNA testing for 18 different HHC mutations, and biochemical testing for percent transferrin saturation (%TS) and ferritin. C282Y mutation was not detected. Only H63D mutation (rs1799945) was found with an overall carrier frequency of 25.8% (24.1% heterozygous and 1.7% homozygous). %TS and ferritin differed significantly between genders. %TS and ferritin were significantly higher in males with H63D mutation when compared to males with wild-type (P=0.001, 0.019; respectively); but not in females. The proportion of subjects with increased %TS and serum ferritin was not statistically different between those with H63D mutation and the wild-type in either gender. In addition, none of the subjects had concurrent increase in %TS and ferritin. In conclusion, the H63D carrier frequency in healthy Lebanese is comparable to other populations in the region, and it does not result in significant biochemical iron overload. Moreover, in the absence of the C282Y mutation, genetic screening for HHC is not recommended according to this preliminary study in healthy Lebanese.

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.

Unique genetic profile of hereditary hemochromatosis in Russians: high frequency of C282Y mutation in population, but not in patients

Hereditary hemochromatosis (HH) is a common cause of primary iron overload induced by genetic impairment of iron metabolism. More than 80% of HH patients in populations of European origin are homozygotes for a single mutation C282Y, or compound heterozygotes for C282Y and H63D mutations in the HFE gene. However, in the majority of Asian, African, Australasian, and Amerindian populations, frequencies of C282Y are close to zero. Data on the prevalence of HFE mutations in Russian population and in Russian patients with HH are very limited. In this work, we determined frequencies of C282Y and H63D in ethnical Russians living in the Central European region of Russia. Furthermore, we tested whether homozygocity for C282Y is the major cause of HH in Russians. We found that, in the Russian population, the frequency of C282Y mutation in the HFE gene is relatively high and corresponds to mean European levels. However, in contrast to the majority of European populations, homozygocity for C282Y is found only in a small proportion (5%) of patients with biochemical and clinical signs of HH. These data suggest that either the penetrance of C282Y in Russia is lower than in Western countries, or that a more frequent non-HFE dependent mechanism of primary iron overload dominates in Russian population.

Serum iron levels and hepatic iron overload in nonalcoholic steatohepatitis and chronic viral hepatitis

Our objective was to determine the effect of serum iron levels and hepatic iron overload on hepatocellular damage in nonalcoholic steatohepatitis (NASH) and to compare this with chronic viral hepatitis. Twenty-five patients who had elevated transaminase levels on at least two occasions, without any evidence of viral and autoimmune hepatitis and diabetes, without a history of significant alcohol use, and with a liver biopsy consistent with NASH were enrolled in the study. Twenty-five patients with chronic viral hepatitis (13 patients with chronic hepatitis C and 12 with chronic hepatitis B) who were not under any antiviral treatment were taken as controls. Metabolic factors were studied in the NASH and chronic hepatitis groups. Biopsy specimens were stained with hematoxylin-eosin, and the grade of steatosis and the stage of fibrosis were evaluated as I, II, or III, I being mild and III being severe. Iron overload in the hepatic tissue was studied by Prussian blue staining. Serum ALT, AST, ALP, GGT, globulin, and ferritin levels were comparable in both steatohepatitis and chronic viral hepatitis groups. However, patients with chronic hepatitis had a lower albumin level and a higher serum iron level, with higher transferrin saturation. Among patients with NASH, mild, moderate, and severe steatosis was found in 7, 10, and 8 patients, respectively. Inflammatory infiltration was grade I in 24 patients and grade III in 1 patient. Fibrosis was mild in 12 patients and 13 patients had no fibrosis. Among patients with chronic viral hepatitis, inflammatory infiltration of grade I was seen in 11 patients, grade II in 11 patients, and grade III in 3 patients. Fibrosis was mild in 9 patients, moderate in 13 patients, and severe in 2 patients; 1 patient had no fibrosis. Compared to patients with NASH, those with chronic viral hepatitis cases had more severe inflammatory infiltration and fibrosis (P < 0.01). While five patients with chronic viral hepatitis had mild iron overload, patients with NASH had no hepatic paranchymal iron overload. Neither NASH nor chronic viral hepatitis revealed a relationship between hepatic iron overload and disease activity. This suggests that the iron overload actually may be a result of hemachromatosis gene mutation. The absence of hepatic parenchymal iron overload in the NASH group and only mild iron accumulation in the chronic hepatitis group may be explained by a lower frequency of the gene mutation in our country.

Frequency ofHFEH63D, S65C, and C282Y Mutations in Patients with Iron Overload and Controls from Toledo, Spain

Hereditary hemochromatosis (HH) is an autosomal recessive disease caused by a defective iron absorption. C282Y is the most frequent HFE gene mutation causing HH in Northern European populations and their descendants. However, two other mutations, H63D and S65C, have been described as pathogenic changes. In this study, we have tried to evaluate the frequency of these three mutations in our community. Eighty-three patients with clinical and/or biochemical features of hemochromatosis and 150 controls were screened for H63D, S65C, and C282Y mutations using a PCR-restriction fragment length polymorphism (RFLP)-based strategy. In contrast to previous studies, 7% of the patients were homozygous for C282Y mutation. The remaining patients were 20% H63D homozygous, 10% H63D/C282Y compound heterozygous, 1% H63D/S65C compound heterozygous, 22% H63D heterozygous, 2% C282Y heterozygous, 2% S65C heterozygous, and 36% of patients lacked any of the three mutations studied, despite the fact that they showed clinical/biochemical features of hemochromatosis. We observed a high frequency of the H63D mutation in both the control group and patients, whereas the main genotypes implicated in HH in our series were H63D homozygous and H63D/C282Y compound heterozygous. We propose that the H63D mutation be analyzed in HH patients from our geographic area. Moreover, further studies are needed to elucidate the role of this mutation in the development of HH and the genetic, environmental or other factors that affect the genotype-phenotype correlation between H63D and hemochromatosis.