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Occupational exposure to lead (Pb) continues to be a serious public health concern and may pose an elevated risk of genetic oxidative damage. In Brazil, car battery manufacturing and recycling factories represent a great source of Pb contamination, and there are no guidelines on how to properly protect workers from exposure or to dispose the process wastes. Previous studies have shown that Pb body burden is associated with genetic polymorphisms, which consequently may influence the toxicity of the metal. The aim of this study was to assess the impact of Pb exposure on DNA oxidative damage, as well as the modulation of hemochromatosis (HFE) polymorphisms on Pb body burden, and the toxicity of Pb, through the analysis of 8-hydroxy-2'-deoxyguanosine (8-OHdG), in subjects occupationally exposed to the metal. Male Pb-exposed workers (n = 236) from car battery manufacturing and recycling factories in Brazil participated in the study. Blood and plasma lead levels (BLL and PLL, respectively) were determined by ICP-MS and urinary 8-OHdG levels were measured by LC-MS/MS, and genotyping of HFE SNPs (rs1799945, C → G; and 1800562, G → A) was performed by TaqMan assays. Our data showed that carriers of at least one variant allele for HFE rs1799945 (CG + GG) tended to have higher PLL than those with the non-variant genotype (ß = 0.34; p = 0.043); further, PLL was significantly correlated with the levels of urinary 8-OHdG (ß = 0.19; p = 0.0060), while workers that carry the variant genotype for HFE rs1800562 (A-allele) showed a prominent increase in 8-OHdG, as a function of PLL (ß = 0.78; p = 0.046). Taken together, our data suggest that HFE polymorphisms may modulate the Pb body burden and, consequently, the oxidative DNA damage induced by the metal.

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RESUMEN La hemocromatosis hereditaria es una enfermedad metabólica infrecuente que afecta primariamente al hígado, y que se caracteriza por un incremento de la absorción intestinal de hierro. Se presentó un paciente de 49 años de edad, evaluado en consulta externa, desde alrededor de dos años atrás, por: astenia, anorexia, artralgias e hiperpigmentación cutánea, asociada a hipertransaminasemia y seronegatividad para virus B y C. Los niveles de saturación de transferrina y ferritina evidenciaron la sobrecarga de hierro, y el estado homocigoto para la mutación C282Y confirmó la sospecha diagnóstica; se descartaron otras condiciones como: hepatitis crónica por virus B y C, esteatohepatitis no alcohólica, anemia hemolítica crónica, anemia sideroblástica, talasemia mayor, u otras enfermedades metabólicas que afectan al hígado. La biopsia hepática mostró hallazgos típicos de esta condición. Las flebotomías semanales fueron bien toleradas y se logró una mejoría clínica del paciente y de los parámetros de laboratorio.

ABSTRACT Hereditary hemochromatosis is an uncommon metabolic disease, primarily affecting the liver in which increased intestinal absorption of iron is seen. We presented a 49- year -old patient who was evaluated in an outpatient clinic for suffering from asthenia, anorexia, arthralgia and skin hyperpigmentation associated with hypertransaminasemia and negative serology for B and C viruses from about two years ago. Serum ferritin, and transferrin saturation levels evidenced iron overload and homozygosity for the C282Y mutation confirmed the suspected diagnosis; other conditions were ruled out such as chronic hepatitis due to B and C viruses, non-alcoholic steatohepatitis, chronic hemolytic anemia, sideroblastic anemia, thalassemia major or some other metabolic diseases affecting the liver. Liver biopsy showed typical findings related to this condition. Weekly phlebotomies were well tolerated, as well as clinical improvement of the patient and laboratory parameters were achieved.

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Resumen: La Hemocromatosis Hereditaria (HH) se define por la acumulación tisular de hierro, predominantemente en hígado, páncreas y miocardio, siendo una de las formas de sobrecarga férrica de causa congénita. El diagnóstico de HH en la edad adulta es poco frecuente en nuestro medio, y debe tenerse en cuenta ante hepatopatías crónicas de etiología incierta, más aún cuando se acompañan de elementos orientadores de afectación de otros tejidos. En este artículo se presenta el caso de un paciente alcoholista que debuta clínicamente con una hemorragia digestiva, contexto en el cual se establece el diagnóstico de cirrosis. Dados los antecedentes familiares de hepatopatía crónica de etiología incierta, el reciente diagnóstico de diabetes, y ante el hallazgo de un perfil de sobrecarga férrica, a pesar del consumo problemático de alcohol, se solicitaron los estudios destinados a confirmar el planteo de HH. El estudio genético en busca de homocigosis del alelo C282Y para el gen HFE resultó positivo. Se iniciaron flebotomías seriadas con buena evolución posterior. Se presenta el caso clínico y se realiza una revisión de la literatura.

Abstract: Hereditary Hemochromatosis (HH) is defined by tissue accumulation of iron, predominantly in theliver, pancreas and myocardium, being one of the forms of iron overload of congenital cause. The diagnosis of HH in adulthood is rare in our environment and must be taken into account in the presence of chronic liver disease of uncertain etiology. In this article we present a clinical case of an alcoholic patient who debuted clinically with a digestive bleeding, context in which the diagnosis of cirrhosis was established. Given the family history of chronic liver disease of uncertain etiology, the recent diagnosis of diabetes, and the finding of a profile of iron overload, despite problematic alcohol consumption, studies were requested to confirm the HH approach. The genetic study in search of homozygosis of the C282Y allele for the HFE gene was positive. Serial phlebotomies were started with favourable evolution at follow-up. The clinical case is presented, and a review of the literature is made.

Resumo: Hemocromatose hereditária (HH) por acumulação de ferro no tecido é definido predominantemente no fígado, no pâncreas e enfarte, uma das formas de sobrecarga de ferro causa congénita. Diagnóstico HH na idade adulta é raro em nossa área, e deve ser considerada a doença hepática crônica de etiologia desconhecida, mesmo quando acompanhadas por elementos de guia de envolvimento de outros tecidos. Este artigo apresenta o caso de um paciente com alcoolismo que estreou clinicamente com uma hemorragia digestiva, um contexto no qual o diagnóstico de cirrose é estabelecido. Dada a história familiar de doença hepática crônica de etiologia desconhecida, o diagnóstico recente de diabetes e antes da conclusão de um perfil de sobrecarga de ferro, apesar do uso problemático de álcool, estudos para confirmar a proposição de HH foram solicitados. O estudo genético em busca de homozigose do alelo C282Y para o gene HFE foi positivo. Flebotomias seriadas com boa evolução posterior foram iniciadas. O caso clínico é apresentado e uma revisão da literatura é feita.

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Introducción: debido a la alta frecuencia de las mutaciones C282Y y H63D del gen HFE, promotor de la hemocromatosis tipo 1 y de las mutaciones S o Z, causantes de la deficiencia de alfa-1-antitripsina (def-A1AT), se han reportado su coexistencia en varios pacientes, por lo que algunos autores han mencionado a las mutaciones en el gen HFE como posible contribuyente al desarrollo de las manifestaciones hepáticas en pacientes con def-A1AT. Objetivo: determinar la frecuencia de las mutaciones C268Y y H63D en pacientes con hepatopatías y diagnóstico presuntivo de def-A1AT. Materiales y métodos: se realizó un estudio descriptivo, conformado por 65 pacientes con hepatopatías, remitidos al laboratorio de biología molecular del Centro Nacional de Genética Médica, para el diagnóstico molecular de las mutaciones S y Z del gen de la alfa-1-antitripsina. Para la amplificación de las mutaciones C282Y y H63D se empleó el método de reacción en cadena de la polimerasa, con polimorfismos en los tamaños de los fragmentos de restricción (PCR-RFLP). Resultados: la frecuencia de las mutaciones C282Y y H63D del gen HFE en los pacientes con diagnostico presuntivo de deficiencia de alfa-1-antitripsina fue de 5,3 % y 17 %, respectivamente. Conclusiones: este estudio mostró que la frecuencia de estas dos mutaciones en la población cubana es alta. Igualmente, se pudo apreciar que ambas mutaciones, aun en estado heterocigoto, parecen jugar un papel fundamental en el desarrollo de diferentes patologías.

Introduction: Due to the high frequency of C282Y and H63D mutations in the HFE gene, promoter type 1 hemochromatosis, and mutations S or Z causing the deficiency of alpha-1-antitrypsin (def-A1AT), studies have shown their coexistence in several patients. As a result, many scientists consider mutations in the HFE gene as a possible contributor to the development of hepatic events in patients with A1AT-def. Aim: To determine the frequency of C268Y and H63D mutations in patients with liver disease and presumptive diagnosis of A1AT-def. Materials and methods: We conducted a descriptive study that involved 65 patients with liver disease who were referred to the Molecular Biology Laboratory of the National Center of Medical Genetics for the molecular diagnosis of S and Z mutations of the gene for alpha-1 antitrypsin. We used the polymerase chain reaction method with polymorphisms in the sizes of the restriction fragments (PCR-RFLP). Results: The frequency of C282Y and H63D mutations of the HFE gene in patients with presumptive diagnosis of deficiency of alpha-1 antitrypsin was 5.3% and 17% respectively. Conclusions: this study showed that the frequency of these two mutations in Cuban population is high. We also observed that both of them, even in heterozygous state, seem to play a main role in the development of different diseases.

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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.

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Iron homeostasis dysregulation has been regarded as an important mechanism in neurodegenerative diseases. The H63D and C282Y polymorphisms in the HFE gene may be involved in the development of sporadic amyotrophic lateral sclerosis (ALS) through the disruption of iron homeostasis. However, studies investigating the relationship between ALS and these two polymorphisms have yielded contradictory outcomes. We performed a meta-analysis to assess the roles of the H63D and C282Y polymorphisms of HFE in ALS susceptibility. PubMed, MEDLINE, EMBASE, and Cochrane Library databases were systematically searched to identify relevant studies. Strict selection criteria and exclusion criteria were applied. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. A fixed- or random-effect model was selected, depending on the results of the heterogeneity test. Fourteen studies were included in the meta-analysis (six studies with 1692 cases and 8359 controls for C282Y; 14 studies with 5849 cases and 13,710 controls for H63D). For the C282Y polymorphism, significant associations were observed in the allele model (Y vs C: OR=0.76, 95%CI=0.62-0.92, P=0.005) and the dominant model (YY+CY vs CC: OR=0.75, 95%CI=0.61-0.92, P=0.006). No associations were found for any genetic model for the H63D polymorphism. The C282Y polymorphism in HFE could be a potential protective factor for ALS in Caucasians. However, the H63D polymorphism does not appear to be associated with ALS.

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La hemocromatosis hereditaria es un trastorno genético. En los últimos años se ha profundizado en el conocimiento de su fisiopatología y diagnóstico. Estos síndromes se caracterizan por sobrecarga de hierro y se distinguen varios subtipos de acuerdo con la mutación existente. Dentro de ellas, las mutaciones en el gen HFE o hemocromatosis hereditaria tipo I es la más común. Esta enfermedad tiene una gran morbilidad y mortalidad asociada a la sobrecarga del mineral. Se presentan 4 pacientes en los que por primera vez en Cuba se identificaron las mutaciones del gen HFE

Hereditary hemochromatosis is a genetic disorder. Detailed studies on its physiopathology and diagnosis have been carried out over the last years. The syndromes are characterized by iron overload and several subtypes are distinguished according to the existing mutation. Among them, the mutations in HFE gene or hereditary hemochromatosis type I is the most common. This disease has a great morbidity and mortality associated to mineral overload. For the first time in Cuba, we report four patients with confirmed mutations in HFE genes

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BACKGROUND: Hereditary hemochromatosis (HH) is a genetic disease caused by the high absorption and deposition of iron in several organs. This accumulation results in several clinical complications such as cirrhosis, arthritis, cardiopathies, diabetes, sexual disorders, and skin darkening. The H63D and C282Y mutations are well defined in the HH etiology. The objective of this article is identification of the H63D and C282Y mutations in the HFE protein gene and the frequency assessment of these mutations in patients with persistent increase of serum ferritin in patients from Natal City from state of Rio Grande do Norte, located in northeastern Brazil. RESULTS: Of the 299 patients studied for C282Y and H63D, 48.49% showed absence of mutation and 51.51% showed some sort of mutation: heterozygous C282Y mutation in 4.35% patients, homozygous C282Y mutation in 2.67% patients, heterozygous H63D mutation in 31.44% patients, homozygous H63D mutation in 8.03% patients, and heterozygous for the mutation in both genes (C282Y/H63D) in 5.02% patients. The S65C mutation was studied in 112 patients and heterozygous mutation (S65D/WT) in 2.67% of patients and double mutation (H63D/S65C) in 1.78% of patients were observed. CONCLUSION: Due to the high prevalence of hemochromatosis, its genetic diagnosis has become a challenge, especially in the high-risk group.

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BACKGROUND: Given the association between iron deficiency and lead absorption, we hypothesized that variants in iron metabolism genes would predict higher blood lead levels in young children. OBJECTIVE: We examined the association between common missense variants in the hemochromatosis (HFE) and transferrin (TF) genes and blood lead levels in 422 Mexican children. METHODS: Archived umbilical cord blood samples were genotyped for HFE (H63D and C282Y) and TF (P570S) variants. Blood lead was measured at 24, 30, 36, 42, and 48 months of age. A total of 341 subjects had at least one follow-up blood lead level available and data available on covariates of interest for inclusion in the longitudinal analyses. We used random-effects models to examine the associations between genotype (HFE, TF, and combined HFE + TF) and repeated measures of blood lead, adjusting for maternal blood lead at delivery and child's concurrent anemia status. RESULTS: Of 422 children genotyped, 17.7, 3.3, and 18.9% carried the HFE H63D, HFE C282Y, and TF P570S variants, respectively. One percent of children carried both the HFE C282Y and TF P570S variants, and 3% of children carried both the HFE H63D and TF P570S variants. On average, carriers of either the HFE (beta = 0.11, p = 0.04) or TF (beta = 0.10, p = 0.08) variant had blood lead levels that were 11% and 10% higher, respectively, than wild-type subjects. In models examining the dose effect, subjects carrying both variants (beta = 0.41, p = 0.006) had blood lead 50% higher than wild-type subjects and a significantly higher odds of having a blood lead level > 10 microg/dL (odds ratio = 18.3; 95% confidence interval, 1.9-177.1). CONCLUSIONS: Iron metabolism gene variants modify lead metabolism such that HFE variants are associated with increased blood lead levels in young children. The joint presence of variant alleles in the HFE and TF genes showed the greatest effect, suggesting a gene-by-gene-by-environment interaction.

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