1
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Badminton MN, Anderson KE, Deybach JC, Harper P, Sandberg S, Elder GH. From chemistry to genomics: A concise history of the porphyrias. Liver Int 2024; 44:2144-2155. [PMID: 38767598 DOI: 10.1111/liv.15960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/15/2024] [Accepted: 04/18/2024] [Indexed: 05/22/2024]
Abstract
We describe developments in understanding of the porphyrias associated with each step in the haem biosynthesis pathway and the role of individuals whose contributions led to major advances over the past 150 years. The first case of erythropoietic porphyria was reported in 1870, and the first with acute porphyria in 1889. Photosensitisation by porphyrin was confirmed by Meyer-Betz, who self-injected haematoporphyrin. Günther classified porphyrias into haematoporphyria acuta, acuta toxica, congenita and chronica. This was revised by Waldenström into porphyria congenita, acuta and cutanea tarda, with the latter describing those with late-onset skin lesions. Waldenström was the first to recognise porphobilinogen's association with acute porphyria, although its structure was not solved until 1953. Hans Fischer was awarded the Nobel prize in 1930 for solving the structure of porphyrins and the synthesis of haemin. After 1945, research by several groups elucidated the pathway of haem biosynthesis and its negative feedback regulation by haem. By 1961, following the work of Watson, Schmid, Rimington, Goldberg, Dean, Magnus and others, aided by the availability of modern techniques of porphyrin separation, six of the porphyrias were identified and classified as erythropoietic or hepatic. The seventh, 5-aminolaevulinate dehydratase deficiency porphyria, was described by Doss in 1979. The discovery of increased hepatic 5-aminolaevulinate synthase activity in acute porphyria led to development of haematin as a treatment for acute attacks. By 2000, all the haem biosynthesis genes were cloned, sequenced and assigned to chromosomes and disease-specific mutations identified in all inherited porphyrias. These advances have allowed definitive family studies and development of new treatments.
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Affiliation(s)
| | - Karl E Anderson
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas, USA
| | - Jean-Charles Deybach
- French Porphyria Reference Center (CRMR Porphyries France), University Paris, Paris, France
| | - Pauline Harper
- Department of Medical Biochemistry and Biophysics, Centre for inherited Metabolic Diseases, Porphyria Centre Sweden, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Sverre Sandberg
- Department of Medical Biochemistry and Biophysics, Centre for inherited Metabolic Diseases, Porphyria Centre Sweden, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- Department of Medical Biochemistry and Pharmacology, Norwegian Porphyria Centre, Haukeland University Hospital, Bergen, Norway
- Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, Bergen, Norway
- Institute of Public Health and Primary Health Care, University of Bergen, Bergen, Norway
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2
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Poli A, Schmitt C, Puy H, Talbi N, Lefebvre T, Gouya L. Erythropoietic protoporphyrias: updates and advances. Trends Mol Med 2024; 30:863-874. [PMID: 38890030 DOI: 10.1016/j.molmed.2024.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/10/2024] [Accepted: 05/15/2024] [Indexed: 06/20/2024]
Abstract
Protoporphyrias are caused by pathogenic variants in genes encoding enzymes involved in heme biosynthesis. They induce the accumulation of a hydrophobic phototoxic compound, protoporphyrin (PPIX), in red blood cells (RBCs). PPIX is responsible for painful cutaneous photosensitivity, which severely impairs quality of life. Hepatic elimination of PPIX increases the risk of cholestatic liver disease, requiring lifelong monitoring. Treatment options are scarce and mainly limited to supportive care such as protection from visible light. Here, we review the pathophysiology of protoporphyrias, their diagnosis, and current recommendations for medical care. We discuss new therapeutic strategies, some of which are currently undergoing clinical trials and are likely to radically alter the severity of the disease in the years to come.
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Affiliation(s)
- Antoine Poli
- Institut National de la Santé et de la Recherche Médicale U1149, Centre de Recherche sur l'Inflammation, Paris, France; Université Paris Cité, Paris, France; Assistance Publique-Hôpitaux de Paris, Centre de Référence Maladies Rares Porphyries, Hôpital Louis Mourier, Colombes, France; Laboratory of excellence Gr-Ex, Paris, France.
| | - Caroline Schmitt
- Institut National de la Santé et de la Recherche Médicale U1149, Centre de Recherche sur l'Inflammation, Paris, France; Université Paris Cité, Paris, France; Assistance Publique-Hôpitaux de Paris, Centre de Référence Maladies Rares Porphyries, Hôpital Louis Mourier, Colombes, France; Laboratory of excellence Gr-Ex, Paris, France
| | - Hervé Puy
- Institut National de la Santé et de la Recherche Médicale U1149, Centre de Recherche sur l'Inflammation, Paris, France; Université Paris Cité, Paris, France; Assistance Publique-Hôpitaux de Paris, Centre de Référence Maladies Rares Porphyries, Hôpital Louis Mourier, Colombes, France; Laboratory of excellence Gr-Ex, Paris, France
| | - Neila Talbi
- Institut National de la Santé et de la Recherche Médicale U1149, Centre de Recherche sur l'Inflammation, Paris, France
| | - Thibaud Lefebvre
- Institut National de la Santé et de la Recherche Médicale U1149, Centre de Recherche sur l'Inflammation, Paris, France
| | - Laurent Gouya
- Institut National de la Santé et de la Recherche Médicale U1149, Centre de Recherche sur l'Inflammation, Paris, France; Université Paris Cité, Paris, France; Assistance Publique-Hôpitaux de Paris, Centre de Référence Maladies Rares Porphyries, Hôpital Louis Mourier, Colombes, France; Laboratory of excellence Gr-Ex, Paris, France
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3
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Minder AE, Kluijver LG, Barman-Aksözen J, Minder EI, Langendonk JG. Erythropoietic protoporphyrias: Pathogenesis, diagnosis and management. Liver Int 2024. [PMID: 39011756 DOI: 10.1111/liv.16027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 06/22/2024] [Accepted: 06/24/2024] [Indexed: 07/17/2024]
Abstract
The erythropoietic protoporphyrias consist of three ultra-rare genetic disorders of the erythroid heme biosynthesis, including erythropoietic protoporphyria (EPP1), X-linked protoporphyria (XLEPP) and CLPX-protoporphyria (EPP2), which all lead to the accumulation of protoporphyrin IX (PPIX) in erythrocytes. Affected patients usually present from early childhood with episodes of severe phototoxic pain in the skin exposed to visible light. The quantification of PPIX in erythrocytes with a metal-free PPIX ≥3 times the upper limit of normal confirms the diagnosis. Protoporphyria-related complications include liver failure, gallstones, mild anaemia and vitamin D deficiency with reduced bone mineral density. The management is focused on preventing phototoxic reactions and treating the complications. Vitamin D should be supplemented, and DEXA scans in adults should be considered. In EPP1, even in cases of biochemically determined iron deficiency, supplementation of iron may stimulate PPIX production, resulting in an increase in photosensitivity and the risk of cholestatic liver disease. However, for patients with XLEPP, iron supplementation can reduce PPIX levels, phototoxicity and liver damage. Because of its rarity, there is little data on the management of EPP-related liver disease. As a first measure, any hepatotoxins should be eliminated. Depending on the severity of the liver disease, phlebotomies, exchange transfusions and ultimately liver transplantation with subsequent haematopoietic stem cell transplantation (HSCT) are therapeutic options, whereby multidisciplinary management including porphyria experts is mandatory. Afamelanotide, an alpha-melanocyte-stimulating hormone analogue, is currently the only approved specific treatment that increases pain-free sunlight exposure and quality of life.
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Affiliation(s)
- Anna-Elisabeth Minder
- Division of Endocrinology, Diabetology, and Porphyria, Stadtspital Zürich Triemli, Zurich, Switzerland
- Swiss Reference Centre for Porphyrias, Stadtspital Zürich Triemli, Zurich, Switzerland
| | - Louisa G Kluijver
- Department of Internal Medicine, Porphyria Center Rotterdam, Center for Lysosomal and Metabolic Disease, Erasmus MC, University Medical Center, Rotterdam, The Netherlands
| | - Jasmin Barman-Aksözen
- Swiss Reference Centre for Porphyrias, Stadtspital Zürich Triemli, Zurich, Switzerland
- Institute of Laboratory Medicine, Stadtspital Zürich Triemli, Zurich, Switzerland
- University of Zurich, Zurich, Switzerland
| | - Elisabeth I Minder
- Division of Endocrinology, Diabetology, and Porphyria, Stadtspital Zürich Triemli, Zurich, Switzerland
- Swiss Reference Centre for Porphyrias, Stadtspital Zürich Triemli, Zurich, Switzerland
- University of Zurich, Zurich, Switzerland
| | - Janneke G Langendonk
- Department of Internal Medicine, Porphyria Center Rotterdam, Center for Lysosomal and Metabolic Disease, Erasmus MC, University Medical Center, Rotterdam, The Netherlands
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4
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Balogun O, Nejak-Bowen K. The Hepatic Porphyrias: Revealing the Complexities of a Rare Disease. Semin Liver Dis 2023; 43:446-459. [PMID: 37973028 PMCID: PMC11256094 DOI: 10.1055/s-0043-1776760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The porphyrias are a group of metabolic disorders that are caused by defects in heme biosynthesis pathway enzymes. The result is accumulation of heme precursors, which can cause neurovisceral and/or cutaneous photosensitivity. Liver is commonly either a source or target of excess porphyrins, and porphyria-associated hepatic dysfunction ranges from minor abnormalities to liver failure. In this review, the first of a three-part series, we describe the defects commonly found in each of the eight enzymes involved in heme biosynthesis. We also discuss the pathophysiology of the hepatic porphyrias in detail, covering epidemiology, histopathology, diagnosis, and complications. Cellular consequences of porphyrin accumulation are discussed, with an emphasis on oxidative stress, protein aggregation, hepatocellular cancer, and endothelial dysfunction. Finally, we review current therapies to treat and manage symptoms of hepatic porphyria.
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Affiliation(s)
- Oluwashanu Balogun
- Department of Experimental Pathology, University of Pittsburgh, Pittsburgh, PA
| | - Kari Nejak-Bowen
- Department of Experimental Pathology, University of Pittsburgh, Pittsburgh, PA
- Pittsburgh Liver Institute, University of Pittsburgh, Pittsburgh, PA
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5
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Hill AC, Becker JP, Slominski D, Halloy F, Søndergaard C, Ravn J, Hall J. Peptide Conjugates of a 2'- O-Methoxyethyl Phosphorothioate Splice-Switching Oligonucleotide Show Increased Entrapment in Endosomes. ACS OMEGA 2023; 8:40463-40481. [PMID: 37929104 PMCID: PMC10620785 DOI: 10.1021/acsomega.3c05144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 09/26/2023] [Indexed: 11/07/2023]
Abstract
Antisense oligonucleotides (ASOs) are short, single-stranded nucleic acid molecules that alter gene expression. However, their transport into appropriate cellular compartments is a limiting factor in their potency. Here, we synthesized splice-switching oligonucleotides (SSOs) previously developed to treat the rare disease erythropoietic protoporphyria. Using chemical ligation-quantitative polymerase chain reaction (CL-qPCR), we quantified the SSOs in cells and subcellular compartments following free uptake. To drive nuclear localization, we covalently conjugated nuclear localization signal (NLS) peptides to a lead 2'-O-methoxyethyl phosphorothioate SSO using thiol-maleimide chemistry. The conjugates and parent SSO displayed similar RNA target-binding affinities. CL-qPCR quantification of the conjugates in cells and subcellular compartments following free uptake revealed one conjugate with better nuclear accumulation relative to the parent SSO. However, compared to the parent SSO, which altered the splicing of the target pre-mRNA, the conjugates were inactive at splice correction under free uptake conditions in vitro. Splice-switching activity could be conferred on the conjugates by delivering them into cells via cationic lipid-mediated transfection or by treating the cells into which the conjugates had been freely taken up with chloroquine, an endosome-disrupting agent. Our results identify the major barrier to the activity of the peptide-oligonucleotide conjugates as endosomal entrapment.
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Affiliation(s)
- Alyssa C. Hill
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich
(ETH Zürich), Zürich 8093, Switzerland
| | - J. Philipp Becker
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich
(ETH Zürich), Zürich 8093, Switzerland
| | - Daria Slominski
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich
(ETH Zürich), Zürich 8093, Switzerland
| | - François Halloy
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich
(ETH Zürich), Zürich 8093, Switzerland
| | | | - Jacob Ravn
- Roche
Innovation Center Copenhagen (RICC), Hørsholm 2970, Denmark
| | - Jonathan Hall
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, Eidgenössische Technische Hochschule Zürich
(ETH Zürich), Zürich 8093, Switzerland
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6
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Hussain Z, Qi Q, Zhu J, Anderson KE, Ma X. Protoporphyrin IX-induced phototoxicity: Mechanisms and therapeutics. Pharmacol Ther 2023; 248:108487. [PMID: 37392940 PMCID: PMC10529234 DOI: 10.1016/j.pharmthera.2023.108487] [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: 04/03/2023] [Revised: 06/18/2023] [Accepted: 06/27/2023] [Indexed: 07/03/2023]
Abstract
Protoporphyrin IX (PPIX) is an intermediate in the heme biosynthesis pathway. Abnormal accumulation of PPIX due to certain pathological conditions such as erythropoietic protoporphyria and X-linked protoporphyria causes painful phototoxic reactions of the skin, which can significantly impact daily life. Endothelial cells in the skin have been proposed as the primary target for PPIX-induced phototoxicity through light-triggered generation of reactive oxygen species. Current approaches for the management of PPIX-induced phototoxicity include opaque clothing, sunscreens, phototherapy, blood therapy, antioxidants, bone marrow transplantation, and drugs that increase skin pigmentation. In this review, we discuss the present understanding of PPIX-induced phototoxicity including PPIX production and disposition, conditions that lead to PPIX accumulation, symptoms and individual differences, mechanisms, and therapeutics.
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Affiliation(s)
- Zahir Hussain
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Qian Qi
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Junjie Zhu
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Karl E Anderson
- Porphyria Laboratory and Center, Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Xiaochao Ma
- Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA.
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7
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An Enigmatic Case of Jaundice and Photosensitivity in an Adolescent. ACG Case Rep J 2023; 10:e00996. [PMID: 36891180 PMCID: PMC9988325 DOI: 10.14309/crj.0000000000000996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/30/2023] [Indexed: 03/06/2023] Open
Abstract
Erythropoietic protoporphyria (EPP) presents with nonblistering photosensitivity. Hepatobiliary manifestations are seen in around 5% cases and include cholelithiasis, elevations in liver enzymes, progressive jaundice, and end-stage liver disease. The diagnosis is suspected based on clinical features and elevated erythrocyte metal-free protoporphyrin and confirmed by genetic analysis showing loss-of-function mutations in the ferrochelatase (FECH) gene. We present an adolescent boy who presented with jaundice and photosensitivity with the liver biopsy showing deposition of brown pigments within the canaliculi and hepatocytes. This pigment showed Maltese cross birefringence on polarizing microscopy and Medusa-head appearance on electron microscopy. Genetic analysis revealed loss-of-function mutations in FECH. Introduction of EPP is an inborn error of heme biosynthesis caused by mutations in FECH with a prevalence of 1:75,000 to 1:200,000. We present a case of a 16-year-old adolescent boy with photosensitivity, abdominal pain, and jaundice with protoporphyrin deposition in the liver who was ultimately diagnosed with EPP based on genetic analysis.
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8
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Obi CD, Bhuiyan T, Dailey HA, Medlock AE. Ferrochelatase: Mapping the Intersection of Iron and Porphyrin Metabolism in the Mitochondria. Front Cell Dev Biol 2022; 10:894591. [PMID: 35646904 PMCID: PMC9133952 DOI: 10.3389/fcell.2022.894591] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 04/14/2022] [Indexed: 12/29/2022] Open
Abstract
Porphyrin and iron are ubiquitous and essential for sustaining life in virtually all living organisms. Unlike iron, which exists in many forms, porphyrin macrocycles are mostly functional as metal complexes. The iron-containing porphyrin, heme, serves as a prosthetic group in a wide array of metabolic pathways; including respiratory cytochromes, hemoglobin, cytochrome P450s, catalases, and other hemoproteins. Despite playing crucial roles in many biological processes, heme, iron, and porphyrin intermediates are potentially cytotoxic. Thus, the intersection of porphyrin and iron metabolism at heme synthesis, and intracellular trafficking of heme and its porphyrin precursors are tightly regulated processes. In this review, we discuss recent advances in understanding the physiological dynamics of eukaryotic ferrochelatase, a mitochondrially localized metalloenzyme. Ferrochelatase catalyzes the terminal step of heme biosynthesis, the insertion of ferrous iron into protoporphyrin IX to produce heme. In most eukaryotes, except plants, ferrochelatase is localized to the mitochondrial matrix, where substrates are delivered and heme is synthesized for trafficking to multiple cellular locales. Herein, we delve into the structural and functional features of ferrochelatase, as well as its metabolic regulation in the mitochondria. We discuss the regulation of ferrochelatase via post-translational modifications, transportation of substrates and product across the mitochondrial membrane, protein-protein interactions, inhibition by small-molecule inhibitors, and ferrochelatase in protozoal parasites. Overall, this review presents insight on mitochondrial heme homeostasis from the perspective of ferrochelatase.
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Affiliation(s)
- Chibuike David Obi
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Tawhid Bhuiyan
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Harry A. Dailey
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- Department of Microbiology, University of Georgia, Athens, GA, United States
| | - Amy E. Medlock
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- Augusta University/University of Georgia Medical Partnership, University of Georgia, Athens, GA, United States
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9
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Iron, Heme Synthesis and Erythropoietic Porphyrias: A Complex Interplay. Metabolites 2021; 11:metabo11120798. [PMID: 34940556 PMCID: PMC8705723 DOI: 10.3390/metabo11120798] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/18/2021] [Accepted: 11/19/2021] [Indexed: 12/13/2022] Open
Abstract
Erythropoietic porphyrias are caused by enzymatic dysfunctions in the heme biosynthetic pathway, resulting in porphyrins accumulation in red blood cells. The porphyrins deposition in tissues, including the skin, leads to photosensitivity that is present in all erythropoietic porphyrias. In the bone marrow, heme synthesis is mainly controlled by intracellular labile iron by post-transcriptional regulation: translation of ALAS2 mRNA, the first and rate-limiting enzyme of the pathway, is inhibited when iron availability is low. Moreover, it has been shown that the expression of ferrochelatase (FECH, an iron-sulfur cluster enzyme that inserts iron into protoporphyrin IX to form heme), is regulated by intracellular iron level. Accordingly, there is accumulating evidence that iron status can mitigate disease expression in patients with erythropoietic porphyrias. This article will review the available clinical data on how iron status can modify the symptoms of erythropoietic porphyrias. We will then review the modulation of heme biosynthesis pathway by iron availability in the erythron and its role in erythropoietic porphyrias physiopathology. Finally, we will summarize what is known of FECH interactions with other proteins involved in iron metabolism in the mitochondria.
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10
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Erwin AL, Balwani M. Porphyrias in the Age of Targeted Therapies. Diagnostics (Basel) 2021; 11:diagnostics11101795. [PMID: 34679493 PMCID: PMC8534485 DOI: 10.3390/diagnostics11101795] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/26/2021] [Accepted: 09/27/2021] [Indexed: 01/04/2023] Open
Abstract
The porphyrias are a group of eight rare genetic disorders, each caused by the deficiency of one of the enzymes in the heme biosynthetic pathway, resulting in the excess accumulation of heme precursors and porphyrins. Depending on the tissue site as well as the chemical characteristics of the accumulating substances, the clinical features of different porphyrias vary substantially. Heme precursors are neurotoxic, and their accumulation results in acute hepatic porphyria, while porphyrins are photoactive, and excess amounts cause cutaneous porphyrias, which present with photosensitivity. These disorders are clinically heterogeneous but can result in severe clinical manifestations, long-term complications and a significantly diminished quality of life. Medical management consists mostly of the avoidance of triggering factors and symptomatic treatment. With an improved understanding of the underlying pathophysiology and disease mechanisms, new treatment approaches have become available, which address the underlying defects at a molecular or cellular level, and promise significant improvement, symptom prevention and more effective treatment of acute and chronic disease manifestations.
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Affiliation(s)
- Angelika L. Erwin
- Center for Personalized Genetic Healthcare, Cleveland Clinic & Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
- Correspondence: ; Tel.: +1-216-444-9249
| | - Manisha Balwani
- Department of Genetics and Genomics, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
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11
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Nolan DK, Chaudhari B, Franklin SJ, Wijeratne S, Pfau R, Mihalic Mosher T, Crist E, McBride KL, White P, Wilson RK, Hickey SE, Koboldt DC. Hypomorphic alleles pose challenges in rare disease genomic variant interpretation. Clin Genet 2021; 100:775-776. [PMID: 34476810 DOI: 10.1111/cge.14052] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 11/28/2022]
Abstract
Exon skipping associated with an ATP7B intronic variant in a patient with Wilson's disease. (A) Sashimi plot visualization of aligned RNA sequencing data from proband liver tissue at ATP7B exons 14-13-12. The red track shows traditional RNA-seq data; the blue track shows RNA-seq enriched with exon capture (cDNA-cap) which achieves higher depth of protein-coding transcripts. The histogram indicates overall sequencing depth while arcs tabulate the number of junction-spanning reads supporting exon pairs. (B) The domain structure (top) and exon structure (bottom) of ATP7B. Loss of exon 13 (dashed box) would remove a transmembrane domain and disrupt the first phosphorylation domain.
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Affiliation(s)
- Daniel K Nolan
- Division of Genetic & Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Anthropology, The Ohio State University, Columbus, Ohio, USA
| | - Bimal Chaudhari
- Division of Genetic & Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Samuel J Franklin
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Saranga Wijeratne
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Ruthann Pfau
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Department of Pathology, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Theresa Mihalic Mosher
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Erin Crist
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Kim L McBride
- Division of Genetic & Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA.,Center for Cardiovascular Research, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Peter White
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Richard K Wilson
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Scott E Hickey
- Division of Genetic & Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
| | - Daniel C Koboldt
- The Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
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12
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Shetty T, Corson TW. Mitochondrial Heme Synthesis Enzymes as Therapeutic Targets in Vascular Diseases. Front Pharmacol 2020; 11:1015. [PMID: 32760270 PMCID: PMC7373750 DOI: 10.3389/fphar.2020.01015] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 06/23/2020] [Indexed: 01/16/2023] Open
Affiliation(s)
- Trupti Shetty
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Timothy W. Corson
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
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13
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Halloy F, Iyer P, Ćwiek P, Ghidini A, Barman-Aksözen J, Wildner-Verhey van Wijk N, Theocharides APA, Minder E, Schneider-Yin X, Schümperli D, Hall J. Delivery of oligonucleotides to bone marrow to modulate ferrochelatase splicing in a mouse model of erythropoietic protoporphyria. Nucleic Acids Res 2020; 48:4658-4671. [PMID: 32313951 PMCID: PMC7229840 DOI: 10.1093/nar/gkaa229] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/25/2020] [Accepted: 04/09/2020] [Indexed: 12/17/2022] Open
Abstract
Erythropoietic protoporphyria (EPP) is a rare genetic disease in which patients experience acute phototoxic reactions after sunlight exposure. It is caused by a deficiency in ferrochelatase (FECH) in the heme biosynthesis pathway. Most patients exhibit a loss-of-function mutation in trans to an allele bearing a SNP that favors aberrant splicing of transcripts. One viable strategy for EPP is to deploy splice-switching oligonucleotides (SSOs) to increase FECH synthesis, whereby an increase of a few percent would provide therapeutic benefit. However, successful application of SSOs in bone marrow cells is not described. Here, we show that SSOs comprising methoxyethyl-chemistry increase FECH levels in cells. We conjugated one SSO to three prototypical targeting groups and administered them to a mouse model of EPP in order to study their biodistribution, their metabolic stability and their FECH splice-switching ability. The SSOs exhibited distinct distribution profiles, with increased accumulation in liver, kidney, bone marrow and lung. However, they also underwent substantial metabolism, mainly at their linker groups. An SSO bearing a cholesteryl group increased levels of correctly spliced FECH transcript by 80% in the bone marrow. The results provide a promising approach to treat EPP and other disorders originating from splicing dysregulation in the bone marrow.
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Affiliation(s)
- François Halloy
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Pavithra S Iyer
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Paulina Ćwiek
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Alice Ghidini
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | | | | | - Alexandre P A Theocharides
- Department of Medical Oncology and Hematology, University Hospital and University of Zurich, Zurich, Switzerland
| | | | | | - Daniel Schümperli
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
| | - Jonathan Hall
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland
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14
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Phillips JD. Heme biosynthesis and the porphyrias. Mol Genet Metab 2019; 128:164-177. [PMID: 31326287 PMCID: PMC7252266 DOI: 10.1016/j.ymgme.2019.04.008] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 04/10/2019] [Accepted: 04/18/2019] [Indexed: 01/08/2023]
Abstract
Porphyrias, is a general term for a group of metabolic diseases that are genetic in nature. In each specific porphyria the activity of specific enzymes in the heme biosynthetic pathway is defective and leads to accumulation of pathway intermediates. Phenotypically, each disease leads to either neurologic and/or photocutaneous symptoms based on the metabolic intermediate that accumulates. In each porphyria the distinct patterns of these substances in plasma, erythrocytes, urine and feces are the basis for diagnostically defining the metabolic defect underlying the clinical observations. Porphyrias may also be classified as either erythropoietic or hepatic, depending on the principal site of accumulation of pathway intermediates. The erythropoietic porphyrias are congenital erythropoietic porphyria (CEP), and erythropoietic protoporphyria (EPP). The acute hepatic porphyrias include ALA dehydratase deficiency porphyria, acute intermittent porphyria (AIP), hereditary coproporphyria (HCP) and variegate porphyria (VP). Porphyria cutanea tarda (PCT) is the only porphyria that has both genetic and/or environmental factors that lead to reduced activity of uroporphyrinogen decarboxylase in the liver. Each of the 8 enzymes in the heme biosynthetic pathway have been associated with a specific porphyria (Table 1). Mutations affecting the erythroid form of ALA synthase (ALAS2) are most commonly associated with X-linked sideroblastic anemia, however, gain-of-function mutations of ALAS2 have also been associated with a variant form of EPP. This overview does not describe the full clinical spectrum of the porphyrias, but is meant to be an overview of the biochemical steps that are required to make heme in both erythroid and non-erythroid cells.
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Affiliation(s)
- John D Phillips
- Division of Hematology, Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT, United States of America.
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15
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Balwani M. Erythropoietic Protoporphyria and X-Linked Protoporphyria: pathophysiology, genetics, clinical manifestations, and management. Mol Genet Metab 2019; 128:298-303. [PMID: 30704898 PMCID: PMC6656624 DOI: 10.1016/j.ymgme.2019.01.020] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 01/23/2019] [Accepted: 01/23/2019] [Indexed: 11/18/2022]
Abstract
Erythropoietic Protoporphyria (EPP) and X-linked Protoporphyria (XLP) are rare, genetic photodermatoses resulting from defects in enzymes of the heme-biosynthetic pathway. EPP results from the partial deficiency of ferrochelatase, and XLP results from gain-of-function mutations in erythroid specific ALAS2. Both disorders result in the accumulation of erythrocyte protoporphyrin, which is released in the plasma and taken up by the liver and vascular endothelium. The accumulated protoporphyrin is activated by sunlight exposure, generating singlet oxygen radical reactions leading to tissue damage and excruciating pain. About 2-5% of patients develop clinically significant liver dysfunction due to protoporphyrin deposition in bile and/or hepatocytes which can advance to cholestatic liver failure requiring transplantation. Clinically these patients present with acute, severe, non-blistering phototoxicity within minutes of sun-exposure. Anemia is seen in about 47% of patients and about 27% of patients will develop abnormal serum aminotransferases. The diagnosis of EPP and XLP is made by detection of markedly increased erythrocyte protoporphyrin levels with a predominance of metal-free protoporphyrin. Genetic testing by sequencing the FECH or ALAS2 gene confirms the diagnosis. Treatment is limited to sun-protection and there are no currently available FDA-approved therapies for these disorders. Afamelanotide, a synthetic analogue of α-melanocyte stimulating hormone was found to increase pain-free sun exposure and improve quality of life in adults with EPP. It has been approved for use in the European Union since 2014 and is not available in the U.S. In addition to the development of effective therapeutics, future studies are needed to establish the role of iron and the risks related to the development of hepatopathy in these patients.
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MESH Headings
- 5-Aminolevulinate Synthetase/genetics
- Anemia/etiology
- Clinical Trials as Topic
- Dermatitis, Phototoxic
- Disease Management
- Genes, X-Linked
- Heme/metabolism
- Humans
- Liver Diseases/etiology
- Liver Diseases/physiopathology
- Porphyrias, Hepatic/complications
- Porphyrias, Hepatic/genetics
- Porphyrias, Hepatic/physiopathology
- Porphyrias, Hepatic/therapy
- Protoporphyria, Erythropoietic/complications
- Protoporphyria, Erythropoietic/genetics
- Protoporphyria, Erythropoietic/physiopathology
- Protoporphyria, Erythropoietic/therapy
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Affiliation(s)
- Manisha Balwani
- Department of Genetics and Genomic Sciences and Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
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16
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Johnson AF, Nguyen HT, Veitia RA. Causes and effects of haploinsufficiency. Biol Rev Camb Philos Soc 2019; 94:1774-1785. [DOI: 10.1111/brv.12527] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 05/08/2019] [Accepted: 05/10/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Adam F. Johnson
- Institute of Research and DevelopmentDuy Tan University Da Nang, 550000 Vietnam
| | - Ha T. Nguyen
- Institute of Research and DevelopmentDuy Tan University Da Nang, 550000 Vietnam
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17
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Morice-Picard F. [Genetics and dermatology]. Ann Dermatol Venereol 2019; 146:326-339. [PMID: 31006539 DOI: 10.1016/j.annder.2019.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Many types of genodermatosis exist, with numerous modes of transmission. The development of molecular genetic methods, in particular the most recent sequencing techniques, can be used to identify an increasing number of genes involved in these forms of genodermatosis while providing confirmation or more details regarding clinical diagnosis. Thanks to this approach, it is possible to determine risk of recurrence and to formulate an antenatal strategy. These technologies have led to improved molecular definition and to a better understanding of the physiopathological mechanisms involved in different genodermatoses such as bullous epidermolysis, keratinisation disorders, pigmentation disorders, potentially tumoral conditions, and epidermal and pilar dysplasia. The large amount of information provided by high-throughput sequencing makes it possible to study modifying genes as well as genotype-phenotype correlations. However, this genetic information in its turn poses problems of interpretation and of control of the resulting data. The use of genetics in dermatology for the purposes of diagnosis or research requires a consultation to provide patients with information regarding the genetic tests involved and the potential consequences thereof for them and their families. Furthermore, with pangenomic approaches there is a higher probability of fortuitous discovery of abnormalities such as variants associated with risks predisposing to cancer or neurodegenerative disease. Collaboration between dermatologists and geneticists enables optimisation of patient management in terms of diagnosis and genetic counselling in the event of such rare diseases. Therapeutic applications are beginning to be developed. The scope of therapeutic application includes gene therapy, replacement therapy (enzyme therapy) and targeted therapy.
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Affiliation(s)
- F Morice-Picard
- Service de dermatologie pédiatrique et dermatologie, Centre de référence des maladies rares de la peau, Hôpital pédiatrique, Groupe hospitalier Pellegrin, Centre hospitalier universitaire de Bordeaux, place Amélie-Raba-Léon, 33076 Bordeaux cedex, France.
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18
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A Novel FECH Mutation Causes Erythropoietic Protoporphyria with Severe Liver Dysfunction. HEPATITIS MONTHLY 2018. [DOI: 10.5812/hepatmon.80767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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19
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Baran R, Mascaro JM, Aguilera P. Photoonycholysis: new findings. J Eur Acad Dermatol Venereol 2018; 33:56-62. [PMID: 29953667 DOI: 10.1111/jdv.15151] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 06/06/2018] [Indexed: 11/28/2022]
Abstract
First described in 1961, photoonycholysis (PO) is a rare nail alteration that may result from drug intake, from topical aminolevulinate photodynamic therapy or from photosensitive conditions such as porphyria or pseudoporphyria. Spontaneous PO is rare. This review updates the numerous causes of PO and highlights some new ways producing this condition. Four different types of PO are clearly recognized without relationship with the responsible drug. An updated list of potential inducing drug is provided. Some practical points on PO have been raised. The inability to reproduce photoonycholysis experimentally should be emphasized, and the pathogenesis of PO still needs to be clarified.
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Affiliation(s)
- R Baran
- Honorary Professor of the University of Franche-Comté, Nail Disease Centre, Cannes, France
| | - J M Mascaro
- Professor Emeritus of Dermatology, University of Barcelona, Spain
| | - P Aguilera
- Photodermatology Department, Hospital Clinic de Barcelona, Barcelona, Spain
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20
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Coffey A, Leung DH, Quintanilla NM. Erythropoietic Protoporphyria: Initial Diagnosis With Cholestatic Liver Disease. Pediatrics 2018; 141:S445-S450. [PMID: 29610169 DOI: 10.1542/peds.2016-1625] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/16/2017] [Indexed: 11/24/2022] Open
Abstract
The porphyrias are a group of rare metabolic disorders that result from defects in heme biosynthesis. Erythropoietic protoporphyria (EPP) is the most common inherited porphyria in children and is diagnosed in most individuals after the onset of cutaneous manifestations. Hepatobiliary disease affects the minority of individuals with EPP and usually manifests in patients with an established diagnosis of EPP. We report on a classic but rare case of EPP that masqueraded as cholestasis. An 8-year-old boy was referred to the Hepatology Clinic after an abrupt onset of jaundice with a longstanding history of dermatitis. The diagnosis of EPP was established with liver biopsy, which revealed dense, dark-brown pigment in hepatocytes and Kupffer cells that, on polarization, displayed bright-red birefringence and centrally located Maltese crosses. Plasma total porphyrins and erythrocyte protoporphyrin were elevated and confirmed a diagnosis of EPP. We hope to raise awareness of this diagnosis among pediatricians, hepatologists, and pathologists and increase the consideration of EPP in patients with cholestatic liver disease and chronic dermatitis.
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Affiliation(s)
- Amy Coffey
- Departments of Pathology and Immunology and.,Department of Pathology, Texas Children's Hospital, Houston, Texas
| | - Daniel H Leung
- Pediatrics, Baylor College of Medicine, Houston, Texas; and.,Division of Pediatric Gastroenterology, Hepatology, and Nutrition and
| | - Norma M Quintanilla
- Departments of Pathology and Immunology and .,Department of Pathology, Texas Children's Hospital, Houston, Texas
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21
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Veitia RA, Caburet S, Birchler JA. Mechanisms of Mendelian dominance. Clin Genet 2017; 93:419-428. [PMID: 28755412 DOI: 10.1111/cge.13107] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/24/2017] [Accepted: 07/26/2017] [Indexed: 01/12/2023]
Abstract
Genetic dominance has long been considered as a qualitative reflection of interallelic interactions. Dominance arises from many multiple sources whose unifying theme is the existence of non-linear relationships between the genotypic and phenotypic values. One of the clearest examples are dominant negative mutations (DNMs) in which a defective subunit poisons a macromolecular complex. Dominance can also be due to the presence of a heterozygous null allele, as is the case of haploinsufficiency. Dominance can also be influenced by epistatic (interloci) interactions. For instance, a pre-existing genetic variant can make possible the expression of a pathogenic variant in a seemingly "dominant" fashion. Such interactions, which can make an individual more or less sensitive to a particular pathogenic variant, will also be discussed here.
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Affiliation(s)
- R A Veitia
- Institut Jacques Monod, CNRS-UMR 7592, Paris Cedex 13, France.,Université Paris Diderot, Paris, France
| | - S Caburet
- Institut Jacques Monod, CNRS-UMR 7592, Paris Cedex 13, France.,Université Paris Diderot, Paris, France
| | - J A Birchler
- Division of Biological Sciences, University of Missouri, Columbia, Missouri
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22
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Kim C, Potluri P, Khalil A, Gaut D, McManus M, Compton S, Wallace DC, Yadava N. An X-chromosome linked mouse model (Ndufa1 S55A) for systemic partial Complex I deficiency for studying predisposition to neurodegeneration and other diseases. Neurochem Int 2017; 109:78-93. [PMID: 28506826 DOI: 10.1016/j.neuint.2017.05.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/07/2017] [Accepted: 05/08/2017] [Indexed: 01/19/2023]
Abstract
The respiratory chain Complex I deficiencies are the most common cause of mitochondrial diseases. Complex I biogenesis is controlled by 58 genes and at least 47 of these cause mitochondrial disease in humans. Two of these are X-chromosome linked nuclear (nDNA) genes (NDUFA1 and NDUFB11), and 7 are mitochondrial (mtDNA, MT-ND1-6, -4L) genes, which may be responsible for sex-dependent variation in the presentation of mitochondrial diseases. In this study, we describe an X-chromosome linked mouse model (Ndufa1S55A) for systemic partial Complex I deficiency. By homologous recombination, a point mutation T > G within 55th codon of the Ndufa1 gene was introduced. The resulting allele Ndufa1S55A introduced systemic serine-55-alanine (S55A) mutation within the MWFE protein, which is essential for Complex I assembly and stability. The S55A mutation caused systemic partial Complex I deficiency of ∼50% in both sexes. The mutant males (Ndufa1S55A/Y) displayed reduced respiratory exchange ratio (RER) and produced less body heat. They were also hypoactive and ate less. They showed age-dependent Purkinje neurons degeneration. Metabolic profiling of brain, liver and serum from males showed reduced heme levels in mutants, which correlated with altered expressions of Fech and Hmox1 mRNAs in tissues. This is the first genuine X-chromosome linked mouse model for systemic partial Complex I deficiency, which shows age-dependent neurodegeneration. The effect of Complex I deficiency on survival patterns of males vs. females was different. We believe this model will be very useful for studying sex-dependent predisposition to both spontaneous and stress-induced neurodegeneration, cancer, diabetes and other diseases.
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Affiliation(s)
- Chul Kim
- Pioneer Valley Life Sciences Institute, Springfield, MA 01199, USA
| | - Prasanth Potluri
- Center for Mitochondrial and Epigenomic Medicine at the Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Ahmed Khalil
- Pioneer Valley Life Sciences Institute, Springfield, MA 01199, USA
| | - Daria Gaut
- Center for Mitochondrial and Epigenomic Medicine at the Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Meagan McManus
- Center for Mitochondrial and Epigenomic Medicine at the Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Shannon Compton
- Pioneer Valley Life Sciences Institute, Springfield, MA 01199, USA
| | - Douglas C Wallace
- Center for Mitochondrial and Epigenomic Medicine at the Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Nagendra Yadava
- Pioneer Valley Life Sciences Institute, Springfield, MA 01199, USA; Division of Endocrinology, Diabetes & Metabolism at Baystate Medical Center, Tufts University School of Medicine, Springfield, MA 01199, USA.
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23
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Grillo AS, SantaMaria AM, Kafina MD, Cioffi AG, Huston NC, Han M, Seo YA, Yien YY, Nardone C, Menon AV, Fan J, Svoboda DC, Anderson JB, Hong JD, Nicolau BG, Subedi K, Gewirth AA, Wessling-Resnick M, Kim J, Paw BH, Burke MD. Restored iron transport by a small molecule promotes absorption and hemoglobinization in animals. Science 2017; 356:608-616. [PMID: 28495746 PMCID: PMC5470741 DOI: 10.1126/science.aah3862] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 11/30/2016] [Accepted: 03/21/2017] [Indexed: 12/15/2022]
Abstract
Multiple human diseases ensue from a hereditary or acquired deficiency of iron-transporting protein function that diminishes transmembrane iron flux in distinct sites and directions. Because other iron-transport proteins remain active, labile iron gradients build up across the corresponding protein-deficient membranes. Here we report that a small-molecule natural product, hinokitiol, can harness such gradients to restore iron transport into, within, and/or out of cells. The same compound promotes gut iron absorption in DMT1-deficient rats and ferroportin-deficient mice, as well as hemoglobinization in DMT1- and mitoferrin-deficient zebrafish. These findings illuminate a general mechanistic framework for small molecule-mediated site- and direction-selective restoration of iron transport. They also suggest that small molecules that partially mimic the function of missing protein transporters of iron, and possibly other ions, may have potential in treating human diseases.
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Affiliation(s)
- Anthony S Grillo
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Anna M SantaMaria
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Martin D Kafina
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Alexander G Cioffi
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Nicholas C Huston
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Murui Han
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - Young Ah Seo
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA
| | - Yvette Y Yien
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Christopher Nardone
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Archita V Menon
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA
| | - James Fan
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Dillon C Svoboda
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jacob B Anderson
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - John D Hong
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Bruno G Nicolau
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Kiran Subedi
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Andrew A Gewirth
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Marianne Wessling-Resnick
- Department of Genetic and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
| | - Jonghan Kim
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA 02115, USA.
| | - Barry H Paw
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
- Division of Hematology-Oncology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA
| | - Martin D Burke
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
- Carle-Illinois College of Medicine, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA
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24
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25
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Rose AM, Bhattacharya SS. Variant haploinsufficiency and phenotypic non-penetrance in PRPF31-associated retinitis pigmentosa. Clin Genet 2016; 90:118-26. [PMID: 26853529 DOI: 10.1111/cge.12758] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Revised: 02/02/2016] [Accepted: 02/03/2016] [Indexed: 11/30/2022]
Abstract
Retinitis pigmentosa (RP) is a genetically heterogenous group of inherited disorders, characterized by death of the retinal photoreceptor cells, leading to progressive visual impairment. One form of RP is caused by mutations in the ubiquitously expressed splicing factor, PRPF31, this form being known as RP11. An intriguing feature of RP11 is the presence of non-penetrance, which has been observed in the majority of PRPF31 mutation-carrying families. In contrast to variable expressivity, which is highly pervasive, true non-penetrance is a very rare phenomenon in Mendelian disorders. In this article, the molecular mechanisms underlying phenotypic non-penetrance in RP11 are explored. It is an elegant example of how our understanding of monogenic disorders has evolved from studying only the disease gene, to considering a mutation on the genetic background of the individual - the logical evolution in this genomic era.
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Affiliation(s)
- A M Rose
- Department of Genetics, UCL Institute of Ophthalmology, London, UK
| | - S S Bhattacharya
- Department of Genetics, UCL Institute of Ophthalmology, London, UK
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26
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Sachar M, Anderson KE, Ma X. Protoporphyrin IX: the Good, the Bad, and the Ugly. J Pharmacol Exp Ther 2015; 356:267-75. [PMID: 26588930 DOI: 10.1124/jpet.115.228130] [Citation(s) in RCA: 141] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 11/20/2015] [Indexed: 01/10/2023] Open
Abstract
Protoporphyrin IX (PPIX) is ubiquitously present in all living cells in small amounts as a precursor of heme. PPIX has some biologic functions of its own, and PPIX-based strategies have been used for cancer diagnosis and treatment (the good). PPIX serves as the substrate for ferrochelatase, the final enzyme in heme biosynthesis, and its homeostasis is tightly regulated during heme synthesis. Accumulation of PPIX in human porphyrias can cause skin photosensitivity, biliary stones, hepatobiliary damage, and even liver failure (the bad and the ugly). In this work, we review the mechanisms that are associated with the broad aspects of PPIX. Because PPIX is a hydrophobic molecule, its disposition is by hepatic rather than renal excretion. Large amounts of PPIX are toxic to the liver and can cause cholestatic liver injury. Application of PPIX in cancer diagnosis and treatment is based on its photodynamic effects.
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Affiliation(s)
- Madhav Sachar
- Department of Pharmaceutical Sciences, Center for Pharmacogenetics, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania (M.S., X.M.); and Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, Texas (K.E.A.)
| | - Karl E Anderson
- Department of Pharmaceutical Sciences, Center for Pharmacogenetics, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania (M.S., X.M.); and Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, Texas (K.E.A.)
| | - Xiaochao Ma
- Department of Pharmaceutical Sciences, Center for Pharmacogenetics, School of Pharmacy, University of Pittsburgh, Pittsburgh, Pennsylvania (M.S., X.M.); and Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, Texas (K.E.A.)
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27
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Mizawa M, Makino T, Nakano H, Sawamura D, Shimizu T. Incomplete erythropoietic protoporphyria caused by a splice site modulator homozygous IVS3-48C polymorphism in the ferrochelatase gene. Br J Dermatol 2015; 174:172-5. [PMID: 26280465 DOI: 10.1111/bjd.14078] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/21/2015] [Indexed: 11/29/2022]
Abstract
Erythropoietic protoporphyria (EPP) is an inherited cutaneous porphyria caused by both the partial deficiency of ferrochelatase (FECH) and the existence of cytosine at IVS3-48 in trans to a mutated FECH allele. However, physicians occasionally encounter patients with EPP with a mild phenotype associated with a slight increase in the erythrocyte-free protoporphyrin concentration and no FECH gene mutations. In this study, genetic analyses were performed on three patients with a mild phenotype of EPP, with photosensitivity, slightly increased erythrocyte-free protoporphyrin concentrations and only a few fluorocytes in the peripheral blood. After obtaining the patients' and their parents' informed consent, a direct sequence analysis of the FECH gene and a restriction fragment length polymorphism analysis were performed on samples from the patients. The FECH gene mutation was not detected in the direct sequence analyses in any of the patients. However, all three patients had the homozygous IVS3-48C polymorphism. These findings suggest that homozygous IVS3-48C polymorphism of the FECH gene is associated with a slight elevation of the protoporphyrin level in erythrocytes, resulting in a mild EPP phenotype.
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Affiliation(s)
- M Mizawa
- Department of Dermatology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama, 930-0194, Japan
| | - T Makino
- Department of Dermatology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama, 930-0194, Japan
| | - H Nakano
- Department of Dermatology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, 036-8562, Japan
| | - D Sawamura
- Department of Dermatology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, 036-8562, Japan
| | - T Shimizu
- Department of Dermatology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama, 930-0194, Japan
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Minder EI, Schneider-Yin X. Afamelanotide (CUV1647) in dermal phototoxicity of erythropoietic protoporphyria. Expert Rev Clin Pharmacol 2014; 8:43-53. [DOI: 10.1586/17512433.2014.956089] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Singal AK, Parker C, Bowden C, Thapar M, Liu L, McGuire BM. Liver transplantation in the management of porphyria. Hepatology 2014; 60:1082-9. [PMID: 24700519 PMCID: PMC4498564 DOI: 10.1002/hep.27086] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 02/17/2014] [Indexed: 12/20/2022]
Abstract
UNLABELLED Porphyrias are a group of eight metabolic disorders, each resulting from a mutation that affects an enzyme of the heme biosynthetic pathway. Porphyrias are classified as hepatic or erythropoietic, depending upon the site where the gene defect is predominantly expressed. Clinical phenotypes are classified as follows: (1) acute porphyrias with neurovisceral symptoms: acute intermittent porphyria; delta amino-levulinic acid hydratase deficiency porphyria; hereditary coproporphyria; and variegate porphyria and (2) cutaneous porphyrias with skin blistering and photosensitivity: porphyria cutanea tarda; congenital erythropoietic porphyria; hepatoerythropoietic porphyria and both erythropoietic protoporphyrias: autosomal dominant and X-linked. Liver transplantation (LT) may be needed for recurrent and/or life-threatening acute attack in acute intermittent porphyria or acute liver failure or end-stage chronic liver disease in erythropoietic protoporphyria. LT in acute intermittent porphyria is curative. Erythropoietic protoporphyria patients needing LT should be considered for bone marrow transplantation to achieve cure. CONCLUSION This article provides an overview of porphyria with diagnostic approaches and management strategies for specific porphyrias and recommendations for LT with indications, pretransplant evaluation, and posttransplant management.
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Affiliation(s)
- Ashwani K. Singal
- the Division of Gastroenterology and Hepatology, University of Alabama (UAB), Birmingham, AL
| | - Charles Parker
- Division of Hematology, University of Utah, Salt Lake City, UT
| | | | - Manish Thapar
- Division of Gastroenterology and Hepatology, Drexel University, Philadelphia, PA
| | - Lawrence Liu
- Division of Gastroenterology and Hepatology, Mount Sinai School of Medicine, New York, NY
| | - Brendan M. McGuire
- the Division of Gastroenterology and Hepatology, University of Alabama (UAB), Birmingham, AL
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Oustric V, Manceau H, Ducamp S, Soaid R, Karim Z, Schmitt C, Mirmiran A, Peoc'h K, Grandchamp B, Beaumont C, Lyoumi S, Moreau-Gaudry F, Guyonnet-Dupérat V, de Verneuil H, Marie J, Puy H, Deybach JC, Gouya L. Antisense oligonucleotide-based therapy in human erythropoietic protoporphyria. Am J Hum Genet 2014; 94:611-7. [PMID: 24680888 PMCID: PMC3980518 DOI: 10.1016/j.ajhg.2014.02.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 02/18/2014] [Indexed: 01/05/2023] Open
Abstract
In 90% of people with erythropoietic protoporphyria (EPP), the disease results from the inheritance of a common hypomorphic FECH allele, encoding ferrochelatase, in trans to a private deleterious FECH mutation. The activity of the resulting FECH enzyme falls below the critical threshold of 35%, leading to the accumulation of free protoporphyrin IX (PPIX) in bone marrow erythroblasts and in red cells. The mechanism of low expression involves a biallelic polymorphism (c.315-48T>C) localized in intron 3. The 315-48C allele increases usage of the 3' cryptic splice site between exons 3 and 4, resulting in the transcription of an unstable mRNA with a premature stop codon, reducing the abundance of wild-type FECH mRNA, and finally reducing FECH activity. Through a candidate-sequence approach and an antisense-oligonucleotide-tiling method, we identified a sequence that, when targeted by an antisense oligonucleotide (ASO-V1), prevented usage of the cryptic splice site. In lymphoblastoid cell lines derived from symptomatic EPP subjects, transfection of ASO-V1 reduced the usage of the cryptic splice site and efficiently redirected the splicing of intron 3 toward the physiological acceptor site, thereby increasing the amount of functional FECH mRNA. Moreover, the administration of ASO-V1 into developing human erythroblasts from an overtly EPP subject markedly increased the production of WT FECH mRNA and reduced the accumulation of PPIX to a level similar to that measured in asymptomatic EPP subjects. Thus, EPP is a paradigmatic Mendelian disease in which the in vivo correction of a common single splicing defect would improve the condition of most affected individuals.
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Affiliation(s)
- Vincent Oustric
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France
| | - Hana Manceau
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France
| | - Sarah Ducamp
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France
| | - Rima Soaid
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France
| | - Zoubida Karim
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France; Université Paris Diderot, F-75018 Paris, France
| | - Caroline Schmitt
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France; Université Paris Diderot, F-75018 Paris, France; Assistance Publique-Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier, 178 Rue des Renouillers, F-92701 Colombes, France
| | - Arienne Mirmiran
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France
| | - Katell Peoc'h
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France
| | - Bernard Grandchamp
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France; Université Paris Diderot, F-75018 Paris, France; Assistance Publique-Hôpitaux de Paris, Laboratoire de Biochimie Hormonale et Génétique, Hôpital Bichat, F-75018 Paris, France
| | - Carole Beaumont
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France; Université Paris Diderot, F-75018 Paris, France
| | - Said Lyoumi
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France; Université de Versailles Saint Quentin en Yvelines, F-78035 Versailles, France
| | - François Moreau-Gaudry
- Institut National de la Santé et de la Recherche Médicale, U1035, Biothérapies des Maladies Génétiques et Cancers, Laboratoire d'Excellence du Globule Rouge, F-33000 Bordeaux, France; Université Bordeaux Segalen, F-33000 Bordeaux, France
| | - Véronique Guyonnet-Dupérat
- Institut National de la Santé et de la Recherche Médicale, U1035, Biothérapies des Maladies Génétiques et Cancers, Laboratoire d'Excellence du Globule Rouge, F-33000 Bordeaux, France; Université Bordeaux Segalen, F-33000 Bordeaux, France
| | - Hubert de Verneuil
- Institut National de la Santé et de la Recherche Médicale, U1035, Biothérapies des Maladies Génétiques et Cancers, Laboratoire d'Excellence du Globule Rouge, F-33000 Bordeaux, France; Université Bordeaux Segalen, F-33000 Bordeaux, France
| | - Joëlle Marie
- Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, UPR 3404, Avenue de Terrasse, 91198 Gif-sur-Yvette, Université Paris-Sud, 91400 Orsay, France
| | - Herve Puy
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France; Université Paris Diderot, F-75018 Paris, France; Assistance Publique-Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier, 178 Rue des Renouillers, F-92701 Colombes, France; Assistance Publique-Hôpitaux de Paris, Laboratoire de Biochimie Hormonale et Génétique, Hôpital Bichat, F-75018 Paris, France
| | - Jean-Charles Deybach
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France; Université Paris Diderot, F-75018 Paris, France; Assistance Publique-Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier, 178 Rue des Renouillers, F-92701 Colombes, France; Assistance Publique-Hôpitaux de Paris, Laboratoire de Biochimie Hormonale et Génétique, Hôpital Bichat, F-75018 Paris, France.
| | - Laurent Gouya
- Institut National de la Santé et de la Recherche Médicale, U1149, Centre de Recherches sur l'Inflammation, F-75018 Paris, France; Assistance Publique-Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier, 178 Rue des Renouillers, F-92701 Colombes, France; Université de Versailles Saint Quentin en Yvelines, F-78035 Versailles, France; Assistance Publique-Hôpitaux de Paris, Laboratoire de Biochimie Hormonale et Génétique, Hôpital Ambroise Paré, F-92100 Boulogne Billancourt, France; Laboratory of Excellence GR-Ex, 75000 Paris, France
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Cooper DN, Krawczak M, Polychronakos C, Tyler-Smith C, Kehrer-Sawatzki H. Where genotype is not predictive of phenotype: towards an understanding of the molecular basis of reduced penetrance in human inherited disease. Hum Genet 2013; 132:1077-130. [PMID: 23820649 PMCID: PMC3778950 DOI: 10.1007/s00439-013-1331-2] [Citation(s) in RCA: 423] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 06/15/2013] [Indexed: 02/06/2023]
Abstract
Some individuals with a particular disease-causing mutation or genotype fail to express most if not all features of the disease in question, a phenomenon that is known as 'reduced (or incomplete) penetrance'. Reduced penetrance is not uncommon; indeed, there are many known examples of 'disease-causing mutations' that fail to cause disease in at least a proportion of the individuals who carry them. Reduced penetrance may therefore explain not only why genetic diseases are occasionally transmitted through unaffected parents, but also why healthy individuals can harbour quite large numbers of potentially disadvantageous variants in their genomes without suffering any obvious ill effects. Reduced penetrance can be a function of the specific mutation(s) involved or of allele dosage. It may also result from differential allelic expression, copy number variation or the modulating influence of additional genetic variants in cis or in trans. The penetrance of some pathogenic genotypes is known to be age- and/or sex-dependent. Variable penetrance may also reflect the action of unlinked modifier genes, epigenetic changes or environmental factors. At least in some cases, complete penetrance appears to require the presence of one or more genetic variants at other loci. In this review, we summarize the evidence for reduced penetrance being a widespread phenomenon in human genetics and explore some of the molecular mechanisms that may help to explain this enigmatic characteristic of human inherited disease.
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Affiliation(s)
- David N. Cooper
- Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, CF14 4XN UK
| | - Michael Krawczak
- Institute of Medical Informatics and Statistics, Christian-Albrechts University, 24105 Kiel, Germany
| | | | - Chris Tyler-Smith
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
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32
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Balwani M, Doheny D, Bishop DF, Nazarenko I, Yasuda M, Dailey HA, Anderson KE, Bissell DM, Bloomer J, Bonkovsky HL, Phillips JD, Liu L, Desnick RJ. Loss-of-function ferrochelatase and gain-of-function erythroid-specific 5-aminolevulinate synthase mutations causing erythropoietic protoporphyria and x-linked protoporphyria in North American patients reveal novel mutations and a high prevalence of X-linked protoporphyria. Mol Med 2013; 19:26-35. [PMID: 23364466 DOI: 10.2119/molmed.2012.00340] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 01/23/2013] [Indexed: 01/08/2023] Open
Abstract
Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are inborn errors of heme biosynthesis with the same phenotype but resulting from autosomal recessive loss-of-function mutations in the ferrochelatase (FECH) gene and gain-of-function mutations in the X-linked erythroid-specific 5-aminolevulinate synthase (ALAS2) gene, respectively. The EPP phenotype is characterized by acute, painful, cutaneous photosensitivity and elevated erythrocyte protoporphyrin levels. We report the FECH and ALAS2 mutations in 155 unrelated North American patients with the EPP phenotype. FECH sequencing and dosage analyses identified 140 patients with EPP: 134 with one loss-of-function allele and the common IVS3-48T>C low expression allele, three with two loss-of-function mutations and three with one loss-of-function mutation and two low expression alleles. There were 48 previously reported and 23 novel FECH mutations. The remaining 15 probands had ALAS2 gain-of-function mutations causing XLP: 13 with the previously reported deletion, c.1706_1709delAGTG, and two with novel mutations, c.1734delG and c.1642C>T(p.Q548X). Notably, XLP represented ~10% of EPP phenotype patients in North America, two to five times more than in Western Europe. XLP males had twofold higher erythrocyte protoporphyrin levels than EPP patients, predisposing to more severe photosensitivity and liver disease. Identification of XLP patients permits accurate diagnosis and counseling of at-risk relatives and asymptomatic heterozygotes.
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Affiliation(s)
- Manisha Balwani
- Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, NY 10029, USA
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Darwich E, Herrero C. New Developments in Erythropoietic Porphyrias. ACTAS DERMO-SIFILIOGRAFICAS 2013. [DOI: 10.1016/j.adengl.2011.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Darwich E, Herrero C. New developments in erythropoietic porphyrias. ACTAS DERMO-SIFILIOGRAFICAS 2012; 104:212-9. [PMID: 22766189 DOI: 10.1016/j.ad.2011.12.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/28/2011] [Accepted: 12/27/2011] [Indexed: 11/24/2022] Open
Abstract
In recent years, important advances have been made in our understanding of the genetics of porphyrias, particularly with respect to erythropoietic protoporphyria (EPP) and congenital erythropoietic porphyria (CEP), 2 forms of erythropoietic porphyria no longer considered to be monogenic. The identification of mutations in genes not previously associated with these disorders as causative factors or modulators of severity has helped to explain the presence of genotypic and phenotypic differences between patients carrying the same mutations. These advances have also led to the identification of causative genetic defects in patients who, based on molecular studies, had no mutations in the uroporphyrinogen III synthase gene UROS (in CEP) or in the ferrochelatase gene FECH (in EPP). Better understanding and characterization of the genetics of porphyrias will allow us to determine genotypic and phenotypic correlations and improve the molecular classification of these diseases, which will have both practical and prognostic implications.
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Affiliation(s)
- E Darwich
- Departamento de Dermatología, Hospital Clínic de Barcelona, IDIBAPS, Universitat de Barcelona, Spain.
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35
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Jentarra GM, Rice SG, Olfers S, Rajan C, Saffen DM, Narayanan V. Skewed allele-specific expression of the NF1 gene in normal subjects: a possible mechanism for phenotypic variability in neurofibromatosis type 1. J Child Neurol 2012; 27:695-702. [PMID: 22068829 DOI: 10.1177/0883073811423439] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neurofibromatosis type 1 is an autosomal dominant disorder characterized by neurocutaneous abnormalities, learning disabilities, and attention-deficit disorder. Neurofibromatosis type 1 symptom severity can be highly variable even within families where all affected members carry the same mutation. We hypothesized that variation in the expression of the normal NF1 allele may be a mechanism that participates in producing variable phenotypes. We performed allelic expression imbalance assays on healthy control individuals to estimate the prevalence of skewed allelic expression of the NF1 gene. Approximately 30% of individuals in our sample population showed significant skewing of allelic expression away from the expected 50:50 ratio, indicating that differential regulation of the NF1 alleles occurs in a high proportion of individuals. Differences of up to 25% in allele-specific expression of the NF1 alleles were identified. In individuals with Neurofibromatosis type 1, who carry a mutant allele (haploinsufficient), this degree of expression skewing may be sufficient to modulate the phenotype.
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Affiliation(s)
- Garilyn M Jentarra
- Neurology Research Department, Barrow Neurological Institute, Phoenix, AZ 85013, USA
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36
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Colombo F, Rossetti M, Méndez M, Martínez J, Enríquez de Salamanca R, del C. Batlle A, Parera V. Functional associations of genetic variants involved in the clinical manifestation of erythropoietic protoporphyria in the Argentinean population. J Eur Acad Dermatol Venereol 2012; 27:754-62. [DOI: 10.1111/j.1468-3083.2012.04566.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Abnormal mitoferrin-1 expression in patients with erythropoietic protoporphyria. Exp Hematol 2011; 39:784-94. [PMID: 21627978 DOI: 10.1016/j.exphem.2011.05.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 04/08/2011] [Accepted: 04/16/2011] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Most patients with erythropoietic protoporphyria have deficient ferrochelatase (FECH) activity due to changes in FECH DNA. We evaluated seven patients with erythropoietic protoporphyria phenotype in whom abnormalities of FECH DNA were not found by conventional analysis. The major focus was mitoferrin-1 (MFRN1), the mitochondrial transporter of Fe used for heme formation by FECH and for 2Fe2S cluster synthesis, which is critical to FECH activity/stability. MATERIALS AND METHODS Four patients had a deletion in ALAS2 that causes enzyme gain-of-function, resulting in increased formation of protoporphyrin; one had a heterozygous major deletion in FECH DNA. All had an abnormal transcript of MFRN1 in messenger RNA extracted from blood leukocytes and/or liver tissue. The abnormal transcript contained an insert of intron 2 that had a stop codon. The consequences of abnormal MFRN1 expression were examined using zebrafish and yeast MFRN-deficient strains and cultured lymphoblasts from the patients. RESULTS Abnormal human MFRN1 complementary DNA showed loss-of-function in zebrafish and yeast mutants, whereas normal human MFRN1 complementary DNA rescued both. Using cultured lymphoblasts, quantitative reverse transcription polymerase chain reaction showed increased formation of abnormal transcript that was accompanied by decreased formation of normal transcript and reduced FECH activity in patients compared to normal lines. A positive correlation coefficient (0.75) was found between FECH activity and normal MFRN1 messenger RNA in lymphoblasts. However, no obvious cause for increased formation of abnormal transcript was identified in MFRN1 exons and splice junctions. CONCLUSIONS Abnormal MFRN1 expression can contribute to erythropoietic protoporphyria phenotype in some patients, probably by causing a reduction in FECH activity.
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Frank J, Poblete-Gutiérrez P. Delayed diagnosis and diminished quality of life in erythropoietic protoporphyria: results of a cross-sectional study in Sweden. J Intern Med 2011; 269:270-4. [PMID: 21332583 DOI: 10.1111/j.1365-2796.2010.02283.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tahara T, Yamamoto M, Akagi R, Harigae H, Taketani S. The low expression allele (IVS3-48C) of the ferrochelatase gene leads to low enzyme activity associated with erythropoietic protoporphyria. Int J Hematol 2010; 92:769-71. [PMID: 21132468 DOI: 10.1007/s12185-010-0725-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 11/08/2010] [Accepted: 11/09/2010] [Indexed: 11/29/2022]
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Cappellini MD, Brancaleoni V, Graziadei G, Tavazzi D, Di Pierro E. Porphyrias at a glance: diagnosis and treatment. Intern Emerg Med 2010; 5 Suppl 1:S73-80. [PMID: 20865478 DOI: 10.1007/s11739-010-0449-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Porphyrias are a group of eight rare inherited metabolic disorders of heme biosynthesis pathway. Porphyrias are still underdiagnosed, although examinations of urine and plasma are first-line tests for detecting excess of porphyrins or heme precursors in suspected patients. Diagnosis, particularly for the acute forms, is essential to avoid precipitating factors and the use of triggering drugs. Mutation screening of family members is recommended to identify presymptomatic carriers and to prevent acute attacks. The therapeutic approach should be appropriate regarding specific forms of porphyria and treatment should be started promptly.
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Affiliation(s)
- Maria Domenica Cappellini
- Dipartimento di Medicina Interna, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Università degli Studi di Milano, Via F. Sforza 35, 20122, Milan, Italy.
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Schmitt C, Ducamp S, Gouya L, Deybach JC, Puy H. [Inheritance in erythropoietic protoporphyria]. ACTA ACUST UNITED AC 2010; 58:372-80. [PMID: 20850938 DOI: 10.1016/j.patbio.2010.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 01/29/2010] [Indexed: 01/10/2023]
Abstract
Erythropoietic protoporphyria (EPP) is an inherited disorder of heme biosynthesis that results from an accumulation of protoporphyrin IX in erythroid cells, plasma, skin and liver. EPP leads to acute photosensitivity and, in about 2% of patients, liver disease. EPP is a complex syndrome in which two genes are independently involved: FECH and ALAS2. More than 96% of unrelated EPP patients have ferrochelatase (FECH) deficiency (MIM 177000). Four percent of them present with autosomal recessive inheritance with two mutated FECH alleles. In dominant cases (95%) the inheritance of a common hypomorphic IVS3-48C FECH allele trans to a deleterious FECH mutation reduces FECH activity below a critical threshold. The frequency of the IVS3-48C allele differs widely from the Japanese (45%), to Black West Africans (<1%) populations. These differences in the frequency of this single common SNP account for the prevalence of overt EPP in different countries and for the absence of EPP in Black Africans. The phylogenic origin of the IVS3-48C haplotypes strongly suggests that the IVS3-48C allele arose from a single recent mutational event that occurred 60 Kyears ago. Acquired somatic mutation of FECH secondary to myeloid disease may also exceptionally cause EPP (<1%). Finally, about 4% of unrelated EPP patients have X-linked dominant protoporphyria (XLDPP) (MIM 300752) caused by gain-of-function mutations in the ALAS2 gene leading to an increased erythroid heme biosynthesis and subsequently an accumulation of protoporphyrin without any FECH deficiency.
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Affiliation(s)
- C Schmitt
- Centre Français des Porphyries, Service de Biochimie, Hôpital Louis-Mourier, AP-HP, 178 rue des Renouillers, 92701 Colombes cedex, France
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Surin VL, Luchinina YA, Selivanova DS, Pustovoit YS, Karpova IV, Pivnik AV, Luk’ianenko AV, Kravchenko SK. Molecular genetic study of acute intermittent porphyria in Russia: Mutation analysis and functional polymorphism search in porphobilinogen deaminase gene. RUSS J GENET+ 2010. [DOI: 10.1134/s1022795410040149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
Hereditary porphyrias are a group of eight metabolic disorders of the haem biosynthesis pathway that are characterised by acute neurovisceral symptoms, skin lesions, or both. Every porphyria is caused by abnormal function of a separate enzymatic step, resulting in a specific accumulation of haem precursors. Seven porphyrias are the result of a partial enzyme deficiency, and a gain of function mechanism has been characterised in a new porphyria. Acute porphyrias present with acute attacks, typically consisting of severe abdominal pain, nausea, constipation, confusion, and seizure, and can be life-threatening. Cutaneous porphyrias present with either acute painful photosensitivity or skin fragility and blisters. Rare recessive porphyrias usually manifest in early childhood with either severe cutaneous photosensitivity and chronic haemolysis or chronic neurological symptoms with or without photosensitivity. Porphyrias are still underdiagnosed, but when they are suspected, and dependent on clinical presentation, simple first-line tests can be used to establish the diagnosis in all symptomatic patients. Diagnosis is essential to enable specific treatments to be started as soon as possible. Screening of families to identify presymptomatic carriers is crucial to decrease risk of overt disease of acute porphyrias through counselling about avoidance of potential precipitants.
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Affiliation(s)
- Hervé Puy
- Assistance Publique Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier, Colombes, France
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Shimazaki H, Arima Y, Nakano T, Murao M, Nitta Y, Harata M, Kawabe N, Hashimoto S, Nagano K, Ishikawa T, Okumura A, Hayashi K, Katano Y, Kuroda M, Yoshioka K. A case of erythropoietic protoporphyria with severe liver damage. KANZO 2010; 51:175-182. [DOI: 10.2957/kanzo.51.175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
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Posttranslational stability of the heme biosynthetic enzyme ferrochelatase is dependent on iron availability and intact iron-sulfur cluster assembly machinery. Blood 2009; 115:860-9. [PMID: 19965627 DOI: 10.1182/blood-2009-09-243105] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mammalian ferrochelatase, the terminal enzyme in the heme biosynthetic pathway, possesses an iron-sulfur [2Fe-2S] cluster that does not participate in catalysis. We investigated ferrochelatase expression in iron-deficient erythropoietic tissues of mice lacking iron regulatory protein 2, in iron-deficient murine erythroleukemia cells, and in human patients with ISCU myopathy. Ferrochelatase activity and protein levels were dramatically decreased in Irp2(-/-) spleens, whereas ferrochelatase mRNA levels were increased, demonstrating posttranscriptional regulation of ferrochelatase in vivo. Translation of ferrochelatase mRNA was unchanged in iron-depleted murine erythroleukemia cells, and the stability of mature ferrochelatase protein was also unaffected. However, the stability of newly formed ferrochelatase protein was dramatically decreased during iron deficiency. Ferrochelatase was also severely depleted in muscle biopsies and cultured myoblasts from patients with ISCU myopathy, a disease caused by deficiency of a scaffold protein required for Fe-S cluster assembly. Together, these data suggest that decreased Fe-S cluster availability because of cellular iron depletion or impaired Fe-S cluster assembly causes reduced maturation and stabilization of apo-ferrochelatase, providing a direct link between Fe-S biogenesis and completion of heme biosynthesis. We propose that decreased heme biosynthesis resulting from impaired Fe-S cluster assembly can contribute to the pathogenesis of diseases caused by defective Fe-S cluster biogenesis.
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Ma J, Xiao S, An J, Wang X, Xu Q, Dong Y, Feng Y, Wang J. A novel splicing mutation and haplotype analysis of the FECH gene in a Chinese family with erythropoietic protoporphyria. J Eur Acad Dermatol Venereol 2009; 24:726-9. [DOI: 10.1111/j.1468-3083.2009.03471.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Product release rather than chelation determines metal specificity for ferrochelatase. J Mol Biol 2009; 393:308-19. [PMID: 19703464 DOI: 10.1016/j.jmb.2009.08.042] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 08/13/2009] [Accepted: 08/17/2009] [Indexed: 11/23/2022]
Abstract
Ferrochelatase (protoheme ferrolyase, E.C. 4.99.1.1) is the terminal enzyme in heme biosynthesis and catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme IX (heme). Within the past two years, X-ray crystallographic data obtained with human ferrochelatase have clearly shown that significant structural changes occur during catalysis that are predicted to facilitate metal insertion and product release. One unanswered question about ferrochelatase involves defining the mechanism whereby some metals, such as divalent Fe, Co, Ni, and Zn, can be used by the enzyme in vitro to produce the corresponding metalloporphyrins, while other metals, such as divalent Mn, Hg, Cd, or Pb, are inhibitors of the enzyme. Through the use of high-resolution X-ray crystallography along with characterization of metal species via their anomalous diffraction, the identity and position of Hg, Cd, Ni, or Mn in the center of enzyme-bound porphyrin macrocycle were determined. When Pb, Hg, Cd, or Ni was present in the macrocycle, the conserved pi helix was in the extended, partially unwound "product release" state. Interestingly, in the structure of ferrochelatase with Mn-porphyrin bound, the pi helix is not extended or unwound and is in the "substrate-bound" conformation. These findings show that at least in the cases of Mn, Pb, Cd, and Hg, metal "inhibition" of ferrochelatase is not due to the inability of the enzyme to insert the metal into the macrocycle or by binding to a second metal binding site as has been previously proposed. Rather, inhibition occurs after metal insertion and results from poor or diminished product release. Possible explanations for the lack of product release are proposed herein.
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Parera VE, Koole RH, Minderman G, Edixhoven A, Rossetti MV, Batlle A, de Rooij FWM. Novel null-allele mutations and genotype-phenotype correlation in Argentinean patients with erythropoietic protoporphyria. Mol Med 2009; 15:425-31. [PMID: 19693296 DOI: 10.2119/molmed.2009.00006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Accepted: 08/11/2009] [Indexed: 11/06/2022] Open
Abstract
Erythropoietic protoporphyria (EPP) is an inherited disorder of porphyrin metabolism in which decreased activity of ferrochelatase (FECH) leads to accumulation of protoporphyrin IX (PP IX) in red blood cells, plasma, liver, and bile, and increased PP IX excretion in feces. Clinically, EPP is characterized by photosensitivity that begins in early childhood and includes burning, swelling, itching, and painful erythema in sun-exposed areas. Chronic liver disease is an important complication in a minority of EPP patients, and in some cases liver transplantation has been performed. So far, about 110 different mutations and several polymorphisms have been characterized in the human FECH gene. The relationship between mutations, polymorphisms, and porphyria development in Argentinean patients was investigated. This is the first genetic study carried out in the Argentinean population. In five Argentinean EPP families we detected three novel mutations: a deletion (451delT) producing a stop codon located 18 codons downstream from the mutation and two splicing mutations: IVS1-2A>G leading to exon 2 skipping and IVS4-2A>G, which causes the loss of the first 48 bp of exon 5. We also found two previously described mutations: C343T and 400delA, which produce stop codons. All patients had an FECH activity 25% of normal and also had the polymorphisms -251A>G in the promoter region and IVS1-23 C>T and IVS3-48 T>C. Our findings provide supporting evidence for the concept that the inheritance of the low expression allele IVS3-48C in trans with a mutation in the FECH gene is necessary for EPP to become clinically manifest.
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Affiliation(s)
- Victoria E Parera
- Laboratory of Metabolic Diseases, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands
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Lyoumi S, Martin‐Schmitt C, Touitou Y, Puy H, Djeridane Y. Melatonin and Environmental Lighting Regulate ALA‐S Gene Expression and So Porphyrin Biosynthesis in the Rat Harderian Gland. Chronobiol Int 2009; 25:851-67. [DOI: 10.1080/07420520802548242] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Méndez M, Poblete-Gutiérrez P, Morán-Jiménez MJ, Rodriguez ME, Garrido-Astray MC, Fontanellas A, Frank J, de Salamanca R. A homozygous mutation in the ferrochelatase gene underlies erythropoietic protoporphyria associated with palmar keratoderma. Br J Dermatol 2009; 160:1330-4. [DOI: 10.1111/j.1365-2133.2009.09084.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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