Interaction between haemochromatosis and transferrin receptor genes in multiple myeloma

Spatio-temporal dynamics of water quality in river sources of drinking water in Uttarakhand with reference to human health

Any contamination in potable water leads to high risk on human health. Hence, it is inevitable to characterize water quality and assess temporal change with reference to human health. In this paper, nineteen water quality parameters from 50 sources of drinking water supply operated by state agency Uttarakhand Jal Sansthan (UJS) were analysed. The water samples were collected for pre-monsoon (May) and post-monsoon (November) seasons for the year 2010, 2011, 2018 and 2019. Multivariate analysis such as Pearson's correlation coefficient (r), K-mean, hierarchical clustering and principle component analysis (PCA) were applied to examine the drinking water quality at source sites. The strength of correlation among the parameters is reduced over the time. Cluster analysis provides six major hydro-chemical clusters in the study region. Clusters were compact during 2010-2011 and converted to overlapping structure in later period. The size of clusters was change from two clusters to six clusters during 2018-2019. These hydro-chemical clusters were examined through PCA and established six major hydro-chemical components of water quality. The physico-chemical parameters, namely, pH, alkalinity, TH, TDS, Na, K, Ca, Mg, Cl and SO₄, were in PC-1, the heavy metals in PC-3, turbidity in PC-4, TC in PC-5 and PC-6 is combination of turbidity, NO₃ and TC, whereas PC-2 was a mix of pH and Na and K salts. Study highlighted that the water quality has changed over the time due to runoff of plant debris, erosion, agricultural fertilizer, development activities and local geology hosts. Each PCs was mapped with associated human health issues. Result reveals that structures and pattern of PCs indicate several human health diseases over the later period with seasonal effects.

HFE C282Y mutation as a genetic modifier influencing disease susceptibility for chronic myeloproliferative disease

Iron metabolism has been implicated in carcinogenesis and several studies assessed the potential role of genetic variants of proteins involved in iron metabolism (HFE C282Y, TFR S142G) in different malignancies. Few reports addressed this issue with relation to chronic myeloproliferative disorders (CMPD). The aims of our study were (a) to examine the potential associations of CMPD development with genetic modifiers of iron metabolism in a large cohort of CMPD patients; (b) to examine associations of genetic variants of proteins involved in iron metabolism; and acquired JAK2 V617F mutation with clinical characteristics of CMPD. HFE C282Y was genotyped in 328 CMPD patients and 996 blood donors as controls, HFE H63D, and TFR S142G were tested in CMPD patients and 171 first time blood donors. JAK2 V617F mutation was tested in CMPD patients and in 122 repeated blood donors. Decreased C282Y allele frequency (allele frequency+/-95% confidence interval) was found in the CMPD group (1.8%+/-1.0%) compared with controls (3.4%+/-0.8%; P=0.048). TFR S142G allele frequency was reduced among V617F-negative CMPD patients (34.8%+/-7.6%) compared with controls (47.8%+/-5.4%; P=0.02). The frequency of JAK2 V617F was 75.9% (249 of 328) in the CMPD group. At presentation, elevated hemoglobin levels were found in V617F-positive patients compared with V617F-negative counterparts (P<0.000). Vascular complications (26.6% versus 15.2%; P=0.039) as well as female gender (57.4% versus 41.8%; P=0.019) were more common in V617F-positive patients. We found that HFE C282Y might be associated with a protective role against CMPD. Because chronic iron deficiency or latent anemia may trigger disease susceptibility for CMPD, HFE C282Y positivity may be a genetic factor influencing this effect.

Evidence for an association between compound heterozygosity for germ line mutations in the hemochromatosis (HFE) gene and increased risk of colorectal cancer

Whereas a recent study reported an increased risk of colorectal cancer associated with any HFE germ line mutation (C282Y or H63D), other investigators have concluded there is no increased risk, or that any increase is dependent on polymorphisms in HFE-interacting genes such as the transferrin receptor (TFR). We have established the frequency of HFE mutations in colorectal cancer patients (n = 327) with a family history of the disease and randomly selected controls (n = 322); this design increases greatly the study's power. Genotyping for the TRF S142G polymorphism was also conducted on a large proportion of the study group. Using PCR, restriction enzyme mapping, sequencing followed by data analysis with Fisher's exact test and logistic regression, we show that the presence of any HFE mutation (Y282 or D63) was not associated with colorectal cancer risk (P = 0.57). In contrast, individuals compound heterozygous for both mutations (15 cases versus 5 controls) had thrice the odds of developing colorectal cancer (odds ratio, 3.03; 95% confidence interval, 1.06-8.61) compared with those with a single mutation. This finding did not quite reach statistical significance after allowing for multiple post hoc testing (P(observed) = 0.038 versus P = 0.025, with Bonferonni correction). Overall, our data indicate that individuals with a single HFE mutation, C282Y or H63D, are unlikely predisposed to develop colorectal cancer. However, risk of colorectal cancer might be increased by compound heterozygosity for the HFE mutations in the small number of subjects studied. TFR gene polymorphism was not an independent risk factor and did not modify the disease risk associated with HFE mutation.

HFE gene mutations in susceptibility to childhood leukemia: HuGE review

The hereditary hemochromatosis (HHC) gene, HFE on chromosome 6p21.3, encodes a protein involved in iron homeostasis. HFE mutations have low penetrance with a mild effect on serum iron levels. Animal, twin, and population studies have shown that carrier state for C282Y can increase iron levels. A proportion of heterozygotes show slightly elevated serum iron levels. Increased serum iron has been suggested to increase the risk for oxidative damage to DNA. Epidemiologic studies established a correlation between iron levels and cancer risk. Case-control studies have reported associations between HFE mutations C282Y/H63D and several cancers, some of which in interaction with the transferrin receptor gene TFRC or dietary iron intake. Increased cancer risk in C282Y carriers is likely due to higher iron levels in a multifactorial setting. In childhood acute lymphoblastic leukemia (ALL), there is an association of C282Y with a gender effect in two British populations. No association has been found in acute myeloblastic leukemia and Hodgkin disease in adults. The childhood leukemia association possibly results from elevated intracellular iron in lymphoid cells increasing the vulnerability to DNA damage at a critical time window during lymphoid cell development. Interactions of HFE with environmental and genetic factors, most of which are recognized, may play a role in modification of susceptibility to leukemia conferred by C282Y. Given the population frequency of C282Y and the connection between iron and cancer, clarification of the mechanism of HFE associations in leukemia and cancer will have strong implications in public health.

Analysis of HFE and TFR2 gene mutations in patients with acute leukemia

There are increasing evidences regarding the association between iron overload and extra-hepatic malignancies. We studied the prevalence of 12 hereditary hemochromatosis (HH) gene mutations (C282Y, V53M, V59M, H63D, H63H, S56C, Q127H, E168Q, E168X, W169X and Q283P in the HFE gene and Y250X in the TFR2 gene) and its correlation with the iron status in 82 adult patients with acute leukemia (AL); 48 patients (58.5%) were affected by acute myeloid leukemia (AML) and 34 patients (41.5%) by acute lymphoblastic leukemia (ALL); 27 patients (32.9%) had at least one HH gene mutation (6 heterozygous for C282Y, 6 homozygous for H63D, 13 heterozygous for H63D and 2 heterozygous for S56C). Mean serum ferritin levels at diagnosis were increased (822.5+/-811.4 microg/L). However, there was no difference between patients positive or negative for the HH gene mutations. Similarly, we did not observe any statistically significant difference as far as iron status between AML and ALL patients. Our study does not support the evidence of an association between hemochromatosis gene mutations and iron overload in AL patients.

Increased Prevalence of the HFE C282Y Hemochromatosis Allele in Women with Breast Cancer

Individuals with the major hemochromatosis (HFE) allele C282Y and iron overload develop hepatocellular and some extrahepatic malignancies at increased rates. No association has been previously reported between the C282Y allele and breast cancer. We hypothesized that due to the pro-oxidant properties of iron, altered iron metabolism in C282Y carriers may promote breast carcinogenesis. Because 1 in 10 Caucasians of Northern European ancestry carries this allele, any impact it may have on breast cancer burden is potentially great. We determined C282Y genotypes in 168 patients who underwent high-dose chemotherapy and blood cell transplantation for cancer: 41 with breast cancer and 127 with predominantly hematological cancers (transplant cohort). Demographic, clinical, and tumor characteristics were reviewed in breast cancer patients. The frequency of C282Y genotypes in breast cancers was compared with the frequency in nonbreast cancers, an outpatient sample from Tennessee (n = 169), and a published United States national sample. The frequency of at least one C282Y allele in breast cancers was higher (36.6%, 5 homozygotes/10 heterozygotes) than frequencies in Tennessee (12.7%, P < 0.001), the general population (12.4%, P < 0.001), and similarly selected nonbreast cancers (17.0%, P = 0.008). The likelihood of breast cancer in the transplant cohort increased with C282Y allele dose (P(trend) = 0.010). These results were supported by the finding in a nontransplant cohort of a higher frequency of C282Y mutations in Caucasian (18.4%, P = 0.039) and African-American (8.5%, P = 0.005) women with breast cancer than race-specific national frequency estimates. A high prevalence of C282Y alleles in women with breast cancer with and without poor risk features suggests that altered iron metabolism in C282Y carriers may promote the development of breast cancer and/or more aggressive forms of the disease.

HFE C282Y and H63D in adults with malignancies in a community medical oncology practice

BACKGROUND

We sought to compare frequencies of HFE C282Y and H63D alleles and associated odds ratios (OR) in 100 consecutive unrelated white adults with malignancy to those in 318 controls.

METHODS

Data from patients with more than one malignancy were analyzed according to each primary malignancy. For the present study, OR > or =2.0 or < or =0.5 was defined to be increased or decreased, respectively.

RESULTS

There were 110 primary malignancies (52 hematologic neoplasms, 58 carcinomas) in the 100 adult patients. Allele frequencies were similar in patients and controls (C282Y: 0.0850 vs. 0.0896, respectively (OR = 0.9); H63D: 0.1400 vs. 0.1447, respectively (OR = 0.9)). Two patients had hemochromatosis and C282Y homozygosity. With C282Y, increased OR occurred in non-Hodgkin lymphoma, myeloproliferative disorders, and adenocarcinoma of prostate (2.0, 2.8, and 3.4, respectively); OR was decreased in myelodysplasia (0.4). With H63D, increased OR occurred in myeloproliferative disorders and adenocarcinomas of breast and prostate (2.4, 2.0, and 2.0, respectively); OR was decreased in non-Hodgkin lymphoma and B-chronic lymphocytic leukemia (0.5 and 0.4, respectively).

CONCLUSIONS

In 100 consecutive adults with malignancy evaluated in a community medical oncology practice, frequencies of HFE C282Y or H63D were similar to those in the general population. This suggests that C282Y or H63D is not associated with an overall increase in cancer risk. However, odds ratios computed in the present study suggest that increased (or decreased) risk for developing specific types of malignancy may be associated with the inheritance of HFE C282Y or H63D. Study of more patients with these specific types of malignancies is needed to determine if trends described herein would remain and yield significant differences.

Iron and HFE or TfR1 mutations as comorbid factors for development and progression of chronic hepatitis C

BACKGROUND/AIMS

Recent evidence implicates iron as a comorbid factor for development of non-hemochromatotic liver diseases. Mutations or polymorphisms in the HFE gene or the TfR1 gene may influence the accumulation of iron in the liver or other tissues or may influence chronic viral hepatitis apart from effects on iron homeostasis. The aim of this study was to assess the role of hepatic iron, HFE and TfR1 variations on development and progression of chronic hepatitis C infection.

METHODS

We studied 119 consecutive patients with chronic hepatitis C, correlating clinical, laboratory, histopathological, and genetic data. Frequencies of genetic variations were compared with local and national controls.

RESULTS

HFE mutations were more common in patients than controls (48% vs. 38%, P=0.04), and advanced degrees of fibrosis developed at younger ages in subjects with the C282Y mutation (38.6 vs. 46.5 years, P=0.03). Patients carrying C282Y had higher mean hepatic iron concentrations (P=0.02), hepatic iron indices (P<=0.0001), and hepatic fibrosis scores (P=0.01). Hepatic fibrosis was correlated with hepatic iron concentration (P=0.03). TfR1 polymorphisms bore no detectable relation to disease severity or response to therapy.

CONCLUSIONS

Hepatic iron and HFE mutations are comorbid factors that increase development and progression of chronic hepatitis C.

Hemochromatosis gene in leukemia and lymphoma

The gene causing hereditary hemochromatosis (HH), HFE is an HLA class I-like gene with no known immunological function but indirectly related to the immune functions because of its role in iron transport. It is located 6.5 Mb telomeric to HLA-A. The most common mutation of HFE, C282Y, has a Celtic origin and most patients with HH are homozygous for it in Northern European populations. While there is an enormously increased risk for hepatocellular cancer in hemochromatosis that is attributed to the toxic effects of iron, the risk for extra-hepatic cancers is also increased slightly. Recent studies have found genetic associations between several cancers and C282Y but only in the presence of a particular allele of the transferrin receptor gene. This suggests that the increased cancer risk is more likely due to the effects of iron. In childhood acute lymphoblastic leukemia (ALL), however, there is a strong association of C282Y with a gender effect in two different Celtic populations. This association does not require homozygosity for C282Y or an interaction with the transferrin receptor gene, and is male-specific. The other HFE mutation H63D does not confer increased risk to childhood ALL. Acute myeloblastic leukemia and Hodgkin's disease in adults do not have an association with HFE. Its male-specificity, occurrence in childhood and the lack of a gene-dosage effect suggest that the C282Y association in childhood ALL may reflect the involvement of another HLA-linked gene in leukemia susceptibility.

Variable phenotypic presentation of iron overload in H63D homozygotes: are genetic modifiers the cause?

BACKGROUND

First considered as a polymorphism of the HFE gene, the H63D mutation is now widely recognised as a haemochromatosis associated allele. But few H63D homozygotes with clinical manifestations of hereditary haemochromatosis (HH) have been reported. Concurrently, an increasing number of genes have been shown to interact with HFE in iron metabolism.

AIMS

To describe the clinical expression of iron overload (IO) associated with H63D homozygosity, and search for potential genetic modifiers (within the HFE or other genes) that could explain the variability of the phenotypes.

PATIENTS AND METHODS

We retrospectively analysed the clinical phenotype of 56 H63D homozygotes referred for a personal or family history of IO. For each subject we examined intragenic HFE haplotypes and transferrin receptor (TfR) gene polymorphisms and searched for the Y250X mutation on the TFR2 gene. Additionally, we sequenced the HFE gene of H63D homozygotes with HH.

RESULTS

Fifty of 56 subjects had biological and/or clinical abnormalities of iron metabolism. Up to two thirds of patients (n=34) had no acquired cause of IO. Among these, 12 had a phenotypic diagnosis of HH. In the iron loaded group there was a strong prevalence of male patients. No correlation was found between the potential genetic modifiers and phenotypes. No additional mutation of HFE was identified.

CONCLUSION

The variable phenotypes associated with H63D homozygosity do not appear to be linked to other HFE mutations, to the TFR2 Y250X mutation, or to HFE or TfR gene intragenic polymorphisms. The exact role of H63D homozygosity in IO and HH needs to be further investigated in unselected populations.