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Zin OA, Neves LM, Cunha DP, Motta FL, Agonigi BNS, Horovitz DDG, Almeida DC, Malacarne J, Rodrigues APS, Carvalho AB, Rivello CA, Espariz R, Zin AA, Sallum JMF, Vasconcelos ZFM. Genotypic-Phenotypic Correlations of Hereditary Hyperferritinemia-Cataract Syndrome: Case Series of Three Brazilian Families. Int J Mol Sci 2023; 24:11876. [PMID: 37569253 PMCID: PMC10419074 DOI: 10.3390/ijms241511876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/14/2023] [Accepted: 07/19/2023] [Indexed: 08/13/2023] Open
Abstract
Hereditary hyperferritinemia-cataract syndrome (HHCS) is a rare, frequently misdiagnosed, autosomal dominant disease caused by mutations in the FTL gene. It causes bilateral pediatric cataract and hyperferritinemia without iron overload. The objective of this case series, describing three Brazilian families, is to increase awareness of HHCS, as well as to discuss possible phenotypic interactions with concurrent mutations in HFE, the gene associated with autosomal recessive inheritance hereditary hemochromatosis. Whole-exome sequencing was performed in eight individuals with HHCS from three different families, as well as one unaffected member from each family for trio analysis-a total of eleven individuals. Ophthalmological and clinical genetic evaluations were conducted. The likely pathogenic variant c.-157G>A in FTL was found in all affected individuals. They presented slowly progressing bilateral cataract symptoms before the age of 14, with a phenotype of varied bilateral diffuse opacities. Hyperferritinemia was present in all affected members, varying from 971 ng/mL to 4899 ng/mL. There were two affected individuals with one concurrent pathogenic variant in HFE (c.187C>G, p.H63D), who were also the ones with the highest values of serum ferritin in our cohort. Few publications describe individuals with pathogenic mutations in both FTL and HFE genes, and further studies are needed to assess possible phenotypic interactions causing higher values of hyperferritinemia.
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Affiliation(s)
- Olivia A. Zin
- Department of Ophthalmology, Universidade Federal de São Paulo, São Paulo 04039-032, Brazil; (O.A.Z.); (A.P.S.R.); (J.M.F.S.)
- Instituto Brasileiro de Oftalmologia, Rio de Janeiro 22250-040, Brazil; (C.A.R.); (A.A.Z.)
| | - Luiza M. Neves
- Instituto Fernandes Figueira-Fundação Oswaldo Cruz, Rio de Janeiro 22250-020, Brazil; (L.M.N.); (D.P.C.); (B.N.S.A.); (D.D.G.H.); (D.C.A.J.); (J.M.)
- Department of Ophthalmology, Universidade do Estado do Rio de Janeiro, Rio de janeiro 20551-030, Brazil
| | - Daniela P. Cunha
- Instituto Fernandes Figueira-Fundação Oswaldo Cruz, Rio de Janeiro 22250-020, Brazil; (L.M.N.); (D.P.C.); (B.N.S.A.); (D.D.G.H.); (D.C.A.J.); (J.M.)
| | | | - Bruna N. S. Agonigi
- Instituto Fernandes Figueira-Fundação Oswaldo Cruz, Rio de Janeiro 22250-020, Brazil; (L.M.N.); (D.P.C.); (B.N.S.A.); (D.D.G.H.); (D.C.A.J.); (J.M.)
| | - Dafne D. G. Horovitz
- Instituto Fernandes Figueira-Fundação Oswaldo Cruz, Rio de Janeiro 22250-020, Brazil; (L.M.N.); (D.P.C.); (B.N.S.A.); (D.D.G.H.); (D.C.A.J.); (J.M.)
| | - Daltro C. Almeida
- Instituto Fernandes Figueira-Fundação Oswaldo Cruz, Rio de Janeiro 22250-020, Brazil; (L.M.N.); (D.P.C.); (B.N.S.A.); (D.D.G.H.); (D.C.A.J.); (J.M.)
| | - Jocieli Malacarne
- Instituto Fernandes Figueira-Fundação Oswaldo Cruz, Rio de Janeiro 22250-020, Brazil; (L.M.N.); (D.P.C.); (B.N.S.A.); (D.D.G.H.); (D.C.A.J.); (J.M.)
| | - Ana Paula S. Rodrigues
- Department of Ophthalmology, Universidade Federal de São Paulo, São Paulo 04039-032, Brazil; (O.A.Z.); (A.P.S.R.); (J.M.F.S.)
| | | | - Cinthia A. Rivello
- Instituto Brasileiro de Oftalmologia, Rio de Janeiro 22250-040, Brazil; (C.A.R.); (A.A.Z.)
- Instituto Catarata Infantil, Rio de Janeiro 22250-040, Brazil
| | - Rita Espariz
- Department of Hematology, Hospital Federal Cardoso Fontes, Rio de Janeiro 22745-130, Brazil;
| | - Andrea A. Zin
- Instituto Brasileiro de Oftalmologia, Rio de Janeiro 22250-040, Brazil; (C.A.R.); (A.A.Z.)
- Instituto Fernandes Figueira-Fundação Oswaldo Cruz, Rio de Janeiro 22250-020, Brazil; (L.M.N.); (D.P.C.); (B.N.S.A.); (D.D.G.H.); (D.C.A.J.); (J.M.)
- Instituto Catarata Infantil, Rio de Janeiro 22250-040, Brazil
| | - Juliana M. F. Sallum
- Department of Ophthalmology, Universidade Federal de São Paulo, São Paulo 04039-032, Brazil; (O.A.Z.); (A.P.S.R.); (J.M.F.S.)
- Instituto de Genética Ocular, São Paulo 04552-050, Brazil;
| | - Zilton F. M. Vasconcelos
- Instituto Fernandes Figueira-Fundação Oswaldo Cruz, Rio de Janeiro 22250-020, Brazil; (L.M.N.); (D.P.C.); (B.N.S.A.); (D.D.G.H.); (D.C.A.J.); (J.M.)
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Wilkinson N, Pantopoulos K. The IRP/IRE system in vivo: insights from mouse models. Front Pharmacol 2014; 5:176. [PMID: 25120486 PMCID: PMC4112806 DOI: 10.3389/fphar.2014.00176] [Citation(s) in RCA: 224] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/07/2014] [Indexed: 12/16/2022] Open
Abstract
Iron regulatory proteins 1 and 2 (IRP1 and IRP2) post-transcriptionally control the expression of several mRNAs encoding proteins of iron, oxygen and energy metabolism. The mechanism involves their binding to iron responsive elements (IREs) in the untranslated regions of target mRNAs, thereby controlling mRNA translation or stability. Whereas IRP2 functions solely as an RNA-binding protein, IRP1 operates as either an RNA-binding protein or a cytosolic aconitase. Early experiments in cultured cells established a crucial role of IRPs in regulation of cellular iron metabolism. More recently, studies in mouse models with global or localized Irp1 and/or Irp2 deficiencies uncovered new physiological functions of IRPs in the context of systemic iron homeostasis. Thus, IRP1 emerged as a key regulator of erythropoiesis and iron absorption by controlling hypoxia inducible factor 2α (HIF2α) mRNA translation, while IRP2 appears to dominate the control of iron uptake and heme biosynthesis in erythroid progenitor cells by regulating the expression of transferrin receptor 1 (TfR1) and 5-aminolevulinic acid synthase 2 (ALAS2) mRNAs, respectively. Targeted disruption of either Irp1 or Irp2 in mice is associated with distinct phenotypic abnormalities. Thus, Irp1(-/-) mice develop polycythemia and pulmonary hypertension, while Irp2(-/-) mice present with microcytic anemia, iron overload in the intestine and the liver, and neurologic defects. Combined disruption of both Irp1 and Irp2 is incombatible with life and leads to early embryonic lethality. Mice with intestinal- or liver-specific disruption of both Irps are viable at birth but die later on due to malabsorption or liver failure, respectively. Adult mice lacking both Irps in the intestine exhibit a profound defect in dietary iron absorption due to a "mucosal block" that is caused by the de-repression of ferritin mRNA translation. Herein, we discuss the physiological function of the IRE/IRP regulatory system.
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Affiliation(s)
- Nicole Wilkinson
- Lady Davis Institute for Medical Research, Jewish General Hospital, and Department of Medicine, McGill University Montreal, QC, Canada
| | - Kostas Pantopoulos
- Lady Davis Institute for Medical Research, Jewish General Hospital, and Department of Medicine, McGill University Montreal, QC, Canada
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The hereditary hyperferritinemia-cataract syndrome in 2 italian families. Case Rep Pediatr 2013; 2013:806034. [PMID: 24368960 PMCID: PMC3867874 DOI: 10.1155/2013/806034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 11/05/2013] [Indexed: 11/17/2022] Open
Abstract
Two 8- and 9-year-old brothers were referred to the Pediatric Oncology Unit, Perugia General Hospital, because of hyperferritinemia. Both had a history of bilateral cataract and epilepsy. Genetic investigation revealed two distinct mutations in iron haemostasis genes; homozygosity for the HFE gene H63D mutation in the younger and heterozygosity in the elder. Both displayed heterozygosity for C33T mutation in the ferritin light chain iron response element. A 7-year-old boy from another family was referred to our unit because of hyperferritinemia. Genetic analyses did not reveal HFE gene mutations. Family history showed that his mother was also affected by hyperferritinemia without HFE gene mutations. Magnetic resonance imaging in the mother was positive for iron overload in the spleen. Cataract was diagnosed in mother and child. Further genetic investigation revealed the C29G mutation of the ferritin light chain iron response element. C33T and C29G mutations in the ferritin light chain iron response element underlie the Hereditary Hyperferritinemia-Cataract Syndrome (HHCS). The HFE gene H63D mutation underlies Hereditary Haemochromatosis (HH), which needs treatment to prevent organ damages by iron overload. HHCS was definitively diagnosed in all three children. HHCS is an autosomal dominant disease characterized by increased L-ferritin production. L-Ferritin aggregates accumulate preferentially in the lens, provoking bilateral cataract since childhood, as unique known organ damage. Epilepsy in one case and the spleen iron overload in another could suggest the misleading diagnosis of HH. Consequently, the differential diagnosis between alterations of iron storage system was essential, particularly in children, and required further genetic investigation.
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Abstract
ABSTRACT Iron is an essential transition metal for mammalian cellular and tissue viability. It is critical to supplying oxygen through heme, the mitochondrial respiratory chain, and enzymes such as ribonucleotide reductase. Mammalian organisms have evolved with the means of regulating the metabolism of iron, because if left unregulated, the resulting excess amounts of iron may induce chronic toxicities affecting multiple organ systems. Several homeostatic mechanisms exist to control the amount of intestinal dietary iron uptake, cellular iron uptake, distribution, and export. Within these processes, numerous molecular participants have been identified because of advancements in basic cell biology and efforts in disease-based research of iron storage abnormalities. For example, dietary iron uptake across the intestinal duodenal mucosa is mediated by an intramembrane divalent metal transporter 1 (DMT1), and cellular iron efflux involves ferroportin, the only known iron exporter. In addition to duodenal enterocytes, ferroportin is present in other cell types, and exports iron into plasma. Ferroportin was recently discovered to be regulated by the expression of the circulating hormone hepcidin, a small peptide synthesized in hepatocytes. These recent studies on the role of hepcidin in the regulation of dietary, cellular, and extracellular iron have led to a better understanding of the pathways by which iron balance in humans is influenced, especially its involvement in human genetic diseases of iron overload. Other important molecular pathways include iron binding to transferrin in the bloodstream for cellular delivery through the plasma membrane transferrin receptor (TfR1). In the cytosol, iron regulatory proteins 1 and 2 (IRP1 and IRP2) play a prominent role in sensing the presence of iron in order to posttranscriptionally regulate the expression of TfR1 and ferritin, two important participants in iron metabolism. From a toxicological standpoint, posttranscriptional regulation of these genes aids in the sequestration, control, and hence prevention of cytotoxic effects from free-floating nontransferrin-bound iron. Given the importance of dietary iron in normal physiology, its potential to induce chronic toxicity, and recent discoveries in the regulation of human iron metabolism by hepcidin, this review will address the regulatory mechanisms of normal iron metabolism in mammals with emphasis on dietary exposure. It is the goal of this review that this information may provide in a concise format our current understanding of major pathways and mechanisms involved in mammalian iron metabolism, which is a basis for control of iron toxicity. Such a discussion is intended to facilitate the identification of deficiencies so that future metabolic or toxicological studies may be appropriately focused. A better knowledge of iron metabolism from normal to pathophysiological conditions will ultimately broaden the spectrum of the usefulness of this information in biomedical and toxicological sciences for improving and protecting human health.
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Affiliation(s)
- Luis G Valerio
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition,Office of Food Additive Safety, Division of Biotechnology and GRAS Notice Review, College Park, MD, 20470, USA
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Pantopoulos K, Porwal SK, Tartakoff A, Devireddy L. Mechanisms of mammalian iron homeostasis. Biochemistry 2012; 51:5705-24. [PMID: 22703180 DOI: 10.1021/bi300752r] [Citation(s) in RCA: 391] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Iron is vital for almost all organisms because of its ability to donate and accept electrons with relative ease. It serves as a cofactor for many proteins and enzymes necessary for oxygen and energy metabolism, as well as for several other essential processes. Mammalian cells utilize multiple mechanisms to acquire iron. Disruption of iron homeostasis is associated with various human diseases: iron deficiency resulting from defects in the acquisition or distribution of the metal causes anemia, whereas iron surfeit resulting from excessive iron absorption or defective utilization causes abnormal tissue iron deposition, leading to oxidative damage. Mammals utilize distinct mechanisms to regulate iron homeostasis at the systemic and cellular levels. These involve the hormone hepcidin and iron regulatory proteins, which collectively ensure iron balance. This review outlines recent advances in iron regulatory pathways as well as in mechanisms underlying intracellular iron trafficking, an important but less studied area of mammalian iron homeostasis.
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Affiliation(s)
- Kostas Pantopoulos
- Lady Davis Institute for Medical Research, Jewish General Hospital and Department of Medicine, McGill University, Montreal, QC, Canada
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6
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Abstract
Iron is an essential but potentially hazardous biometal. Mammalian cells require sufficient amounts of iron to satisfy metabolic needs or to accomplish specialized functions. Iron is delivered to tissues by circulating transferrin, a transporter that captures iron released into the plasma mainly from intestinal enterocytes or reticuloendothelial macrophages. The binding of iron-laden transferrin to the cell-surface transferrin receptor 1 results in endocytosis and uptake of the metal cargo. Internalized iron is transported to mitochondria for the synthesis of haem or iron–sulfur clusters, which are integral parts of several metalloproteins, and excess iron is stored and detoxified in cytosolic ferritin. Iron metabolism is controlled at different levels and by diverse mechanisms. The present review summarizes basic concepts of iron transport, use and storage and focuses on the IRE (iron-responsive element)/IRP (iron-regulatory protein) system, a well known post-transcriptional regulatory circuit that not only maintains iron homoeostasis in various cell types, but also contributes to systemic iron balance.
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Sebastiani G, Pantopoulos K. Disorders associated with systemic or local iron overload: from pathophysiology to clinical practice. Metallomics 2011; 3:971-86. [DOI: 10.1039/c1mt00082a] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Potentiometric assessment of iron release during ferritin reduction by exogenous agents. Anal Biochem 2010; 404:52-5. [DOI: 10.1016/j.ab.2010.04.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2010] [Revised: 04/15/2010] [Accepted: 04/24/2010] [Indexed: 11/18/2022]
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Sammarco MC, Ditch S, Banerjee A, Grabczyk E. Ferritin L and H subunits are differentially regulated on a post-transcriptional level. J Biol Chem 2007; 283:4578-87. [PMID: 18160403 DOI: 10.1074/jbc.m703456200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Ferritin plays an important role in the storage and release of iron, an element utilized in cellular processes such as respiration, gene regulation, and DNA replication and repair. Ferritin in animals is composed of 24 ferritin L (FTL) and ferritin H (FTH) subunits in ratios that vary in different cell types. Because the subunits are not functionally interchangeable, both L and H units are critical for maintaining iron homeostasis and protecting against iron overload. FTL and FTH are regulated primarily at a post-transcriptional level in response to cellular iron concentrations. Individual regulation of FTL and FTH is of much interest, and although transcriptional differences between FTL and FTH have been shown, differences in their post-transcriptional regulation have not been evaluated. We report here that FTL and FTH are differentially regulated in 1% oxygen on a post-transcriptional level. We have designed a quantitative assay system sensitive enough to detect differences between FTL and FTH iron regulatory elements (IREs) that a standard electrophoretic mobility shift assay does not. The FTL IRE is the primary responder in the presence of an iron donor in hypoxic conditions, and this response is reflected in endogenous FTL protein levels. These results provide evidence that FTL and FTH subunits respond independently to cellular iron concentrations and underscore the importance of evaluating FTL and FTH IREs separately.
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Affiliation(s)
- Mimi C Sammarco
- Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA
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Abstract
An RNA hairpin structure referred to as the iron-responsive element (IRE) and iron regulatory proteins (IRPs) are key players in the control of iron metabolism in animal cells. They regulate translation initiation or mRNA stability, and the IRE is found in a variety of mRNAs, such as those encoding ferritin, transferrin receptor (Tfr), erythroid aminolevulinic acid synthase (eALAS), mitochondrial aconitase (mACO), ferroportin, and divalent metal transporter 1 (DMT1). We have studied the evolution of the IRE by considering all mRNAs previously known to be associated with this structure and by computationally examining its occurrence in a large variety of eukaryotic organisms. More than 100 novel sequences together with approximately 50 IREs that were previously reported resulted in a comprehensive view of the phylogenetic distribution of this element. A comparison of the different mRNAs shows that the IREs of eALAS and mACO are found in chordates, those of ferroportin and Tfr1 are found in vertebrates, and the IRE of DMT1 is confined to mammals. In contrast, the IRE of ferritin occurs in a majority of metazoa including lower metazoa such as sponges and Nematostella (sea anemone). These findings suggest that the ferritin IRE represents the ancestral version of this type of translational control and that during the evolution of higher animals the IRE structure was adopted by other genes. On the basis of primary sequence comparison between different organisms, we suggest that some of these IREs developed by "convergent evolution" through stepwise changes in sequence, rather than by recombination events.
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Affiliation(s)
- Paul Piccinelli
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden
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Ferrari F, Foglieni B, Arosio P, Camaschella C, Daraio F, Levi S, García Erce JA, Beaumont C, Cazzola M, Ferrari M, Cremonesi L. Microelectronic DNA chip for hereditary hyperferritinemia cataract syndrome, a model for large-scale analysis of disorders of iron metabolism. Hum Mutat 2006; 27:201-8. [PMID: 16395671 DOI: 10.1002/humu.20294] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Hereditary hyperferritinemia cataract syndrome (HHCS) is caused by mutations in the regulatory iron responsive element (IRE) in the 5'UTR of the L-ferritin transcript that reduce binding affinity to the iron regulatory proteins (IRPs) and lead to a constitutive upregulation of the protein in tissue and serum. Twenty-nine mutations have been reported within the L-ferritin (FTL) IRE sequence, 21 of which were available to us. In addition, we included in this study three new mutations. Thus, we analyzed 24 mutations spanning over a DNA stretch of 48 nucleotides, including four deletions 2-29 nucleotides long and 20 substitutions, seven of which were conservative transversions. With this unique experimental model we developed a microchip diagnostic platform for identifying known molecular defects in the L-ferritin IRE structure with a microelectronic array approach, which we optimized after studying the effects of various parameters. The system enables electronic deposition of biotinylated amplicons to selected pads. Under optimized conditions, no cross-hybridization was found, even for mutations that affected the same or adjacent nucleotide positions. The same cartridge could be serially hybridized with all the 24 reporter probe sets, which allowed correct genotyping right up until the end of the analysis. Extensive validation on 200 samples in a blinded fashion gave total concordance of results. This pilot study represents a first step toward developing a diagnostic microchip for large-scale analyses for epidemiological studies and screening of mutations associated with iron disorders.
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Affiliation(s)
- Francesca Ferrari
- Unit of Genomics for Diagnosis of Human Pathologies, IRCCS H. San Raffaele, Milan, Italy
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Abstract
Haemochromatosis is the most common genetic disease in populations of European ancestry. Despite estimates based on genetic testing in Caucasian populations of 1 in 227, many physicians consider haemochromatosis to be a rare disease. The diagnosis can be elusive because of the non-specific nature of the symptoms. Of all the symptoms, liver disease has the most consistent relationship to haemochromatosis and the prognosis of haemochromatosis is most closely linked to the degree of iron overload. With the discovery of the HFE gene in 1996, comes new insights into the pathogenesis of the disease and new diagnostic strategies. However, a growing number of new iron-related genes have been discovered and linked to other iron overload syndromes.
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Affiliation(s)
- P C Adams
- Department of Medicine, University of Western Ontario, London, Ontario, Canada.
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Ferrante M, Geubel AP, Fevery J, Marogy G, Horsmans Y, Nevens F. Hereditary hyperferritinaemia-cataract syndrome: a challenging diagnosis for the hepatogastroenterologist. Eur J Gastroenterol Hepatol 2005; 17:1247-53. [PMID: 16215440 DOI: 10.1097/00042737-200511000-00016] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
Hereditary hyperferritinaemia-cataract syndrome (HHCS) is a relatively rare disorder with an autosomal dominant trait. It can be caused by various mutations within the iron responsive element (IRE) of the L-ferritin gene. These mutations result in an increased translation of L-ferritin mRNA and consequently the accumulation of L-ferritin in different fluids and tissues. HHCS patients present with an isolated hyperferritinaemia in the absence of any sign of iron overload. Early onset bilateral cataract, probably due to accumulation of ferritin crystals in the lens, is the only presenting clinical manifestation. Internists, especially gastrohepatologists, should be aware of this syndrome and differentiate it from haemochromatosis which is much more frequent, in order to avoid unnecessary imaging procedures, liver biopsies and an eventual venesection therapy, which will only lead to microcytic anaemia. In the present paper we report the first cases with HHCS diagnosed in Belgium. At diagnosis, the seven known affected members of three different families had ferritin levels between 603 and 3432 microg/l (normal < 150 microg/l), and this in combination with normal iron and transferrin values. All of them were known with early-onset bilateral cataract and our postulated diagnosis of HHCS was confirmed after genetic sequencing of the L-ferritin gene, which showed a C39U point mutation in the first family, and an A40G point mutation in the IRE loop segment in the two other families. The other investigated members of the three families had normal ferritin values, no history of early-onset cataract and genetic analyses could not reveal a mutation in the IRE of their L-ferritin gene. In current clinical practice, gastroenterologists should remember that elevated ferritin levels in the absence of documented iron overload is not haemochromatosis.
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Affiliation(s)
- Marc Ferrante
- Department of Hepatology, University Hospital, Gasthuisberg, Leuven, Belgium
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Beutler L, Beutler E. Hematologically important mutations: iron storage diseases. Blood Cells Mol Dis 2004; 33:40-4. [PMID: 15223009 DOI: 10.1016/j.bcmd.2004.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2004] [Indexed: 11/19/2022]
Affiliation(s)
- Lisa Beutler
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
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Bosio S, Campanella A, Gramaglia E, Porporato P, Longo F, Cremonesi L, Levi S, Camaschella C. C29G in the iron-responsive element of l-ferritin: a new mutation associated with hyperferritinemia-cataract. Blood Cells Mol Dis 2004; 33:31-4. [PMID: 15223007 DOI: 10.1016/j.bcmd.2004.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2004] [Revised: 04/20/2004] [Indexed: 10/26/2022]
Abstract
Hyperferritinemia-cataract syndrome (HHCS) is a dominant disorder characterized by high serum ferritin and early onset of bilateral cataract. The disorder is caused by mutations in the iron-responsive element (IRE) of l-ferritin, which disrupt the postranscriptional control of l-ferritin synthesis. Here, we report a new (C>G) mutation which affects base 29 in the loop (c.-169C>G), previously unrecognized as essential for the stem loop stability. The mutation was identified in two members of an Italian family. Computer modeling and electrophoretic mobility shift assay (EMSA) confirm a decreased affinity of the C29G IRE for IRPs control proteins.
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Affiliation(s)
- Sandra Bosio
- Dipartimento di Scienze Cliniche e Biologiche, University of Turin, Turin, Italy
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