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Bustad HJ, Kallio JP, Vorland M, Fiorentino V, Sandberg S, Schmitt C, Aarsand AK, Martinez A. Acute Intermittent Porphyria: An Overview of Therapy Developments and Future Perspectives Focusing on Stabilisation of HMBS and Proteostasis Regulators. Int J Mol Sci 2021; 22:E675. [PMID: 33445488 PMCID: PMC7827610 DOI: 10.3390/ijms22020675] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/21/2022] Open
Abstract
Acute intermittent porphyria (AIP) is an autosomal dominant inherited disease with low clinical penetrance, caused by mutations in the hydroxymethylbilane synthase (HMBS) gene, which encodes the third enzyme in the haem biosynthesis pathway. In susceptible HMBS mutation carriers, triggering factors such as hormonal changes and commonly used drugs induce an overproduction and accumulation of toxic haem precursors in the liver. Clinically, this presents as acute attacks characterised by severe abdominal pain and a wide array of neurological and psychiatric symptoms, and, in the long-term setting, the development of primary liver cancer, hypertension and kidney failure. Treatment options are few, and therapies preventing the development of symptomatic disease and long-term complications are non-existent. Here, we provide an overview of the disorder and treatments already in use in clinical practice, in addition to other therapies under development or in the pipeline. We also introduce the pathomechanistic effects of HMBS mutations, and present and discuss emerging therapeutic options based on HMBS stabilisation and the regulation of proteostasis. These are novel mechanistic therapeutic approaches with the potential of prophylactic correction of the disease by totally or partially recovering the enzyme functionality. The present scenario appears promising for upcoming patient-tailored interventions in AIP.
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Affiliation(s)
- Helene J. Bustad
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; (H.J.B.); (J.P.K.)
| | - Juha P. Kallio
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; (H.J.B.); (J.P.K.)
| | - Marta Vorland
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, 5021 Bergen, Norway; (M.V.); (S.S.)
| | - Valeria Fiorentino
- INSERM U1149, Center for Research on Inflammation (CRI), Université de Paris, 75018 Paris, France; (V.F.); (C.S.)
| | - Sverre Sandberg
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, 5021 Bergen, Norway; (M.V.); (S.S.)
- Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, 5009 Bergen, Norway
| | - Caroline Schmitt
- INSERM U1149, Center for Research on Inflammation (CRI), Université de Paris, 75018 Paris, France; (V.F.); (C.S.)
- Assistance Publique Hôpitaux de Paris (AP-HP), Centre Français des Porphyries, Hôpital Louis Mourier, 92700 Colombes, France
| | - Aasne K. Aarsand
- Norwegian Porphyria Centre (NAPOS), Department for Medical Biochemistry and Pharmacology, Haukeland University Hospital, 5021 Bergen, Norway; (M.V.); (S.S.)
- Norwegian Organization for Quality Improvement of Laboratory Examinations (Noklus), Haraldsplass Deaconess Hospital, 5009 Bergen, Norway
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; (H.J.B.); (J.P.K.)
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Granata F, Mendez M, Brancaleoni V, Castelbon FJ, Graziadei G, Ventura P, Di Pierro E. Molecular characterization, by digital PCR analysis of four HMBS gene mutations affecting the ubiquitous isoform of Porphobilinogen Deaminase (PBGD) in patients with Acute Intermittent Porphyria (AIP). Mol Genet Metab 2018; 125:295-301. [PMID: 30201327 DOI: 10.1016/j.ymgme.2018.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/03/2018] [Accepted: 09/03/2018] [Indexed: 12/12/2022]
Abstract
Genetic variants in promoters and alternative-splicing lesions require to be experimentally tested in order to validate them as causatives of a disease. The digital PCR (dPCR) approach, which is an alternative to the classical qPCR, is an innovative and a more sensitive method for the detection and quantification of nucleic acids. In the present study, we identified four HMBS gene mutations affecting the ubiquitous isoform of porphobilinogen deaminase (PBGD) and established a dPCR protocol which would be able to detect the different transcripts of this gene. With the application of this method, we were able to characterize the functional roles of these four genetic variants, demonstrating that all these mutations were causatives of the non-erythroid variant of the acute intermittent porphyria (AIP) disease.
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Affiliation(s)
- Francesca Granata
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, U.O.C. Medicina Generale, Milano, Italy
| | - Manuel Mendez
- Instituto de Investigación, Hospital 12 de Octubre, Madrid, Spain
| | - Valentina Brancaleoni
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, U.O.C. Medicina Generale, Milano, Italy
| | | | - Giovanna Graziadei
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, U.O.C. Medicina Generale, Milano, Italy
| | - Paolo Ventura
- Division of Internal Medicine 2 - Centre for Porphyrias, Dept. of Medical and Surgical Sciences for Children and Adults, University of Modena and Reggio Emilia, Policlinico Hospital, Modena, Italy
| | - Elena Di Pierro
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, U.O.C. Medicina Generale, Milano, Italy.
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Li Y, Qu H, Wang H, Deng H, Liu Z. Novel A219P mutation of hydroxymethylbilane synthase identified in a Chinese woman with acute intermittent porphyria and syndrome of inappropriate antidiuretic hormone. Ann Hum Genet 2015; 79:310-2. [PMID: 25787008 DOI: 10.1111/ahg.12107] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 12/11/2014] [Indexed: 11/30/2022]
Abstract
Acute intermittent porphyria (AIP) is an autosomal dominant metabolic disorder caused by deficiency of the heme biosynthetic enzyme hydroxymethylbilane synthase (approved gene symbol HMBS), also known as porphobilinogen deaminase (PBGD). AIP is characterised by intermittent attacks of abdominal pain, vomiting, and neurological complaints. The highly variable symptomatic presentation of AIP causes confusion with other diseases and results in a high misdiagnosis rate (68% in China) and delayed effective treatments. Based on biochemical and genetic analysis of two Chinese families, a new and a previously reported HMBS mutation were identified in patients with AIP and syndrome of inappropriate antidiuretic hormone (SIADH). The novel HMBS mutation is the 655G>C point mutation (A219P). In addition, the 973C>T point mutation (R325X), which had been previously reported in two Danish families, was identified.
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Affiliation(s)
- Yingjie Li
- Department of Endocrinology, the First Affiliated Hospital of Chongqing Medical University
| | - Hua Qu
- Department of Endocrinology, the First Affiliated Hospital of Chongqing Medical University
| | - Hang Wang
- Department of Endocrinology, the First Affiliated Hospital of Chongqing Medical University
| | - Huacong Deng
- Department of Endocrinology, the First Affiliated Hospital of Chongqing Medical University
| | - Ziyan Liu
- Clinical Laboratory, Guiyang Provincial People's Hospital, 55002, Guiyang, Guizhou Province, China
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Ribeiro GS, Marchiori PE, Hirata MH, Rebecchi I, Ozaki AN, Nagai MA, Santos MLD, Oliveira RAG, Barretto OCDO. A novel 3-base deletion (IVS3+2_4delTGG) of the hydroxymethylbilane synthase gene in a Brazilian patient with acute intermittent porphyria. Genet Mol Biol 2007. [DOI: 10.1590/s1415-47572007000600003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Grünberg-Etkovitz N, Greenbaum L, Grinblat B, Malik Z. Proteasomal degradation regulates expression of porphobilinogen deaminase (PBGD) mutants of acute intermittent porphyria. Biochim Biophys Acta Mol Basis Dis 2006; 1762:819-27. [PMID: 16935474 DOI: 10.1016/j.bbadis.2006.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 07/02/2006] [Accepted: 07/12/2006] [Indexed: 01/29/2023]
Abstract
Acute intermittent porphyria (AIP) is a neuropathic disease caused by a dominant inherited deficiency in porphobilinogen deaminase (PBGD). We investigated the expression and the degradation of the human PBGD-mutations G748A, G748C and 887insA following transfection into human SH-SY5Y neuroblastoma cells. Mutant proteins exhibited reduced protein expression compared to transfected wild-type (wt) PBGD as revealed by Western blotting. The transcription levels assessed by real-time PCR of these mutant species were identical to those of the wild type. Immuno-fluorescence microscopy revealed reduced cellular distribution of the mutated PBGDs in the cytosol and the nucleus in comparison to the wild-type PBGD. Enhanced cellular accumulation of the mutated and wild-type PBGDs was detected following inhibition of the proteasome by the inhibitors CLBL and hemin. Elevated expression of wt and mutated PBGD protein levels was either achieved by hemin or heme-arginate treatment. On the other hand, enhanced PBGD degradation was achieved by lead poisoning of ALAD in the SH-SY5Y cells concomitant with acceleration of proteasomal activity, most probably by ALAD participation in proteasomal regulation [G.G. Guo, M. Gu, J.D. Etlinger, 240-kDa proteasome inhibitor (CF-2) is identical to delta-aminolevulinic acid dehydratase. J Biol Chem 1994; 269:12399-402.] Our results suggest that the difference in expression between the wild-type and mutant proteins appears to be regulated on the level of protein degradation. In conclusion, we demonstrate that the PBGD cellular pool is controlled by the proteasome activity, which in turn is down regulated by hemin or up-regulated by Pb-ALAD.
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To-Figueras J, Badenas C, Carrera C, Muñoz C, Milá M, Lecha M, Herrero C. Genetic and biochemical characterization of 16 acute intermittent porphyria cases with a high prevalence of the R173W mutation. J Inherit Metab Dis 2006; 29:580-5. [PMID: 16817012 DOI: 10.1007/s10545-006-0344-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Accepted: 05/15/2006] [Indexed: 11/28/2022]
Abstract
Acute intermittent porphyria (AIP) is a metabolic disease with a variable prevalence among different countries. In some areas of southern Europe it remains to be fully evaluated. We undertook a genetic and biochemical study of 16 unrelated Spanish AIP patients and relatives. The genetic analyses showed they harboured the following mutations in the porphobilinogen deaminase gene: R173W, G111R, L278P, L238P, R116W, R26C, 340insT, 730delCT, 691del30bp, and IVS14+1g>a. The mutation R173W was found in 6 patients (37.5%), including the only patients of our series with >3 recurrent porphyria attacks. While in clinical remission, all AIP patients exhibited sustained increased excretion of porphyrins and precursors. PBG excretion showed a high between-subject variation and was not related to erythrocyte PBG deaminase activity. The study of family members allowed the identification of 22 asymptomatic AIP carriers. These included 8 persons harbouring the R173W mutation belonging to four different families. Six of these latent AIP subjects showed increased PBG elimination, and in two the urinary levels were >10-fold the normal limit. These results reinforce the hypothesis that the R173W mutation may have a high biochemical and clinical penetrance among AIP patients.
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Affiliation(s)
- J To-Figueras
- Biochemistry and Molecular Genetics Unit, Dermatology Unit, Hospital Clínic i Provincial, IDIBAPS, University of Barcelona, Barcelona, Spain.
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Roca X, Sachidanandam R, Krainer AR. Intrinsic differences between authentic and cryptic 5' splice sites. Nucleic Acids Res 2003; 31:6321-33. [PMID: 14576320 PMCID: PMC275472 DOI: 10.1093/nar/gkg830] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2003] [Revised: 08/25/2003] [Accepted: 09/11/2003] [Indexed: 11/14/2022] Open
Abstract
Cryptic splice sites are used only when use of a natural splice site is disrupted by mutation. To determine the features that distinguish authentic from cryptic 5' splice sites (5'ss), we systematically analyzed a set of 76 cryptic 5'ss derived from 46 human genes. These cryptic 5'ss have a similar frequency distribution in exons and introns, and are usually located close to the authentic 5'ss. Statistical analysis of the strengths of the 5'ss using the Shapiro and Senapathy matrix revealed that authentic 5'ss have significantly higher score values than cryptic 5'ss, which in turn have higher values than the mutant ones. beta-Globin provides an interesting exception to this rule, so we chose it for detailed experimental analysis in vitro. We found that the sequences of the beta-globin authentic and cryptic 5'ss, but not their surrounding context, determine the correct 5'ss choice, although their respective scores do not reflect this functional difference. Our analysis provides a statistical basis to explain the competitive advantage of authentic over cryptic 5'ss in most cases, and should facilitate the development of tools to reliably predict the effect of disease-associated 5'ss-disrupting mutations at the mRNA level.
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Affiliation(s)
- Xavier Roca
- Cold Spring Harbor Laboratory, PO Box 100, Cold Spring Harbor, NY 11724, USA
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Kauppinen R, von und zu Fraunberg M. Molecular and Biochemical Studies of Acute Intermittent Porphyria in 196 Patients and Their Families. Clin Chem 2002. [DOI: 10.1093/clinchem/48.11.1891] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Abstract
Background: Acute intermittent porphyria (AIP) is a metabolic disease with clinical manifestations that mimic other abdominal, neurologic, or mental crises. We studied the diagnostic accuracy of current laboratory tests during an acute attack and in remission.
Methods: Since 1966, we have studied all known Finnish AIP patients (n = 196) and their families (n = 45) and identified the porphobilinogen deaminase (PBGD) mutation in each family. Diagnoses or exclusions of AIP were based on clinical data (including family history), biochemical tests, and in 239 cases, mutation testing. We retrospectively evaluated the diagnostic accuracy of erythrocyte PBGD activity, urinary excretion of porphobilinogen (PBG) and δ-aminolevulinic acid, and urinary and fecal excretion of porphyrins in these patients.
Results: Measurement of urinary PBG identified all 35 AIP patients studied during an acute attack. The mean excretion of PBG was 50-fold above the reference interval, although the intraindividual increases were modest (1.6- to 4.0-fold). In the mutation-screened population, urinary PBG analysis identified only 85% of 81 AIP patients studied during remission, but by ROC curve analysis it was nonetheless the best of the biochemical tests. It was increased ≤2-fold in 29% of healthy relatives. Erythrocyte PBGD activity was decreased in only 84% of AIP patients, with results within the reference interval mainly in the variant form of AIP; it was decreased in 23% of healthy relatives.
Conclusions: Measurement of urinary PBG is the best biochemical test for AIP, although it is unspecific and does not distinguish AIP from other acute porphyrias. Because the acute increase in PBG is often modest, the medical history, signs, and symptoms must be evaluated carefully during an acute attack. In addition, because biochemical analyses often remain indeterminate in remission, mutation analysis is needed to exclude or confirm the diagnosis of AIP.
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Affiliation(s)
- Raili Kauppinen
- Department of Medicine, Division of Endocrinology, University Hospital of Helsinki, 00029 HUS Helsinki, Finland
| | - Mikael von und zu Fraunberg
- Department of Medicine, Division of Endocrinology, University Hospital of Helsinki, 00029 HUS Helsinki, Finland
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Floderus Y, Shoolingin-Jordan PM, Harper P. Acute intermittent porphyria in Sweden. Molecular, functional and clinical consequences of some new mutations found in the porphobilinogen deaminase gene. Clin Genet 2002; 62:288-97. [PMID: 12372055 DOI: 10.1034/j.1399-0004.2002.620406.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Acute intermittent porphyria (AIP) is an autosomal dominant disorder caused by a partial deficit of porphobilinogen deaminase (PBGD), the third of eight enzymes in the haem biosynthetic pathway. The overt disease is characterized by neuropsychiatric symptoms that are often triggered by exogenous factors such as certain drugs, stress, and alcohol. The aim of this work has been to identify the underlying genetic defect in each AIP-affected family in order to provide early counselling to assist in the avoidance of precipitating factors. The prevalence of AIP in Sweden is in the order of 1:10 000. The major mutation in Sweden, W198X, is due to a founder effect in the northern part of the country. This mutation, together with a further 11 mutations, have been reported previously. The present communication encompasses the great majority of AIP kindreds in Sweden and includes a further 27 mutations within the PBGD gene. This includes 14 completely new mutations, as well as 11 known mutations detected for the first time in Sweden. The majority of the mutations are located in exons 10 and 12 with fewer in exon 7. The clinical and biochemical outcomes in some patients are described. We also use the three-dimensional structure of the porphobilinogen deaminase enzyme to predict the possible molecular and functional consequences of the new Swedish missense and nonsense mutations.
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Affiliation(s)
- Y Floderus
- Porphyria Centre Sweden, Huddinge University Hospital, Stockholm, Sweden
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Cartegni L, Chew SL, Krainer AR. Listening to silence and understanding nonsense: exonic mutations that affect splicing. Nat Rev Genet 2002; 3:285-98. [PMID: 11967553 DOI: 10.1038/nrg775] [Citation(s) in RCA: 1591] [Impact Index Per Article: 72.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Point mutations in the coding regions of genes are commonly assumed to exert their effects by altering single amino acids in the encoded proteins. However, there is increasing evidence that many human disease genes harbour exonic mutations that affect pre-mRNA splicing. Nonsense, missense and even translationally silent mutations can inactivate genes by inducing the splicing machinery to skip the mutant exons. Similarly, coding-region single-nucleotide polymorphisms might cause phenotypic variability by influencing splicing accuracy or efficiency. As the splicing mechanisms that depend on exonic signals are elucidated, new therapeutic approaches to treating certain genetic diseases can begin to be explored.
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Affiliation(s)
- Luca Cartegni
- Cold Spring Harbor Laboratory, PO Box 100, Cold Spring Harbor, New York 11724, USA
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11
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Abstract
A population of about 5 million at the northern corner of Europe is unlikely to arouse the attention of the human genetics community, unless it offers something useful for others to learn. A combination of coincidences has finally made this population one that, out of proportion for its size, has by example shaped research in human disease genetics. This chapter summarizes advances made in medical genetics that are based on research facilitated by Finland's population structure. The annotation of the human genome for its polymorphism and involvement in disease is not over; it is, therefore, of interest to assess whether genetic studies in populations such as the Finnish might help in the remaining tasks.
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Affiliation(s)
- J Kere
- Finnish Genome Center, University of Helsinki, Helsinki 00014, Finland.
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Cappellini MD, Martinez di Montemuros F, Di Pierro E, Fiorelli G. Hematologically important mutations: acute intermittent porphyria. Blood Cells Mol Dis 2002; 28:5-12. [PMID: 11814306 DOI: 10.1006/bcmd.2001.0478] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Maria Domenica Cappellini
- Centro Anemie Congenite, Ospedale Maggiore Policlinico IRCCS, Dipartimento di Medicina Interna, University of Milan, Milan, Italy.
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Jørgensen PE, Erlandsen EJ, Poulsen SS, Markussen S, Koch C, Brock A. Activity and immunohistochemical localization of porphobilinogen deaminase in rat tissues. Scand J Clin Lab Invest 2000; 60:635-41. [PMID: 11202056 DOI: 10.1080/003655100448392] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Porphobilinogen deaminase (PBGD) is an enzyme involved in the synthesis of heme. Acute intermittent porphyria (AIP) is an inherited disease resulting from a reduced activity of PBGD. The symptoms seem to be due to a neurological dysfunction. Attacks of AIP are often provoked by conditions where the PBGD activity becomes insufficient as a result of an increased synthesis of heme in the liver. How this affects the nervous tissue is still unknown. It may well be that a reduced activity of PBGD in other tissues than the liver is of importance too. The aim of the present study was to examine the activity and the immunohistochemical localization of PBGD in the following tissues of wistar female rats: brain, heart, submandibular gland, liver, kidney, pancreas, ovary, stomach, duodenum, jejunum, ileum, colon and musculature. The PBGD activity varied considerably among the tissues. It was highest in the liver, 14 pkat/g, and lowest in the jejunum, 0.7 pkat/g. The immunohistochemical localization of PBGD was studied by antibodies raised against a 40 amino acid synthetic peptide that corresponds to a segment in the C-terminal part of PBGD. The study demonstrated that the PBGD immunoreactivity was not evenly distributed among the various cell types in a given tissue. Immunohistochemical reactions were pronounced in Kupffer cells in the liver, in smooth muscle cells of arteries and arterioles, in distal and collecting tubules in the kidney, in nerve axons in the brain and in ganglionic cells in the intestine. Especially, the immunohistochemical reaction in nerve cells is notable considering the nervous dysfunction in AIP.
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Affiliation(s)
- P E Jørgensen
- Department of Clinical Biochemistry, Viborg-Kjellerup County Hospital, Viborg, Denmark.
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Abstract
Porphyrias are divided into erythropoietic and hepatic manifestations. Erythropoietic porphyrias are characterized by cutaneous symptoms and appear in early childhood. Erythropoietic protoporphyria is complicated by cholestatic liver cirrhosis and progressive hepatic failure in 10%, of patients. Acute hepatic porphyrias (delta-aminolaevulinic acid dehydratase deficiency porphyria, acute intermittent porphyria, hereditary coproporphyria and variegate porphyria) are characterized by variable extrahepatic gastrointestinal, neurological-psychiatric and cardiovascular manifestations requiring early diagnosis to avoid life-threatening complications. Acute hepatic porphyrias are pharmacogenetic and molecular regulatory diseases (without porphyrin accumulation) mainly induced by drugs, sex hormones, fasting or alcohol. The disease process depends on the derepression of hepatic delta-aminolaevulinic acid synthase following haem depletion. In contrast to the acute porphyrias, nonacute, chronic hepatic porphyrias such as porphyria cutanea tarda are porphyrin accumulation disorders leading to cutaneous symptoms associated with liver disease, especially caused by alcohol or viral hepatitis. Alcohol, oestrogens, haemodialysis, hepatitis C and AIDS are triggering factors. Porphyria cutanea tarda is the most common porphyria, followed by acute intermittent porphyria and erythropoietic protoporphyria. The molecular genetics of the porphyrias is very heterogenous. Nearly every family has its own mutation. The mutations identified account for the corresponding enzymatic deficiencies, which may remain clinically silent throughout life. Thus, the recognition of the overt disorder with extrahepatic manifestations depends on the demonstration of biochemical abnormalities due to these primary defects and compensatory hepatic overexpression of hepatic delta-aminolaevulinic acid synthase in the acute porphyrias. Consequently, haem precursors are synthesized in excess. The increased metabolites upstream of the enzymatic defect are excreted into urine and faeces. The diagnosis is based on their evaluation. Primary enzymatic or molecular analyses are noncontributary and may be misleading. Acute polysymptomatic exacerbations accompany a high excretory constellation of porphyrin precursors delta-aminolaevulinic acid and porphobilinogen. Homozygous or compound heterozygous variants of acute hepatic porphyrias may already manifest in childhood.
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MESH Headings
- Animals
- Humans
- Porphyria Cutanea Tarda/diagnosis
- Porphyria Cutanea Tarda/genetics
- Porphyria Cutanea Tarda/physiopathology
- Porphyria Cutanea Tarda/therapy
- Porphyria, Acute Intermittent/diagnosis
- Porphyria, Acute Intermittent/genetics
- Porphyria, Acute Intermittent/physiopathology
- Porphyria, Acute Intermittent/therapy
- Porphyria, Erythropoietic/diagnosis
- Porphyria, Erythropoietic/genetics
- Porphyria, Erythropoietic/physiopathology
- Porphyria, Erythropoietic/therapy
- Porphyrias, Hepatic/diagnosis
- Porphyrias, Hepatic/genetics
- Porphyrias, Hepatic/physiopathology
- Porphyrias, Hepatic/therapy
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Affiliation(s)
- U Gross
- Division of Clinical Biochemistry, Faculty of Medicine, Philipps University, Marburg, Germany.
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Ramdall RB, Cunha L, Astrin KH, Katz DR, Anderson KE, Glucksman M, Bottomley SS, Desnick RJ. Acute intermittent porphyria: novel missense mutations in the human hydroxymethylbilane synthase gene. Genet Med 2000; 2:290-5. [PMID: 11399210 DOI: 10.1097/00125817-200009000-00004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To identify mutations in families with acute intermittent porphyria, an autosomal dominant inborn error of metabolism that results from the half-normal activity of the third enzyme in the heme biosynthetic pathway, hydroxymethylbilane synthase. METHODS Mutations were identified by direct solid phase sequencing. RESULTS Two novel missense mutations E80G and T78P and three previously reported mutations, R173W, G111R, and the splice site lesion, IVS1+1, were detected, each in an unrelated proband. The causality of the novel missense mutations was demonstrated by expression studies. CONCLUSION These findings provide for the precise diagnosis of carriers in these families and further expand the molecular heterogeneity of AIP.
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Affiliation(s)
- R B Ramdall
- Departments of Human Genetic, Mount Sinai School of Medicine, New York, New York 10029, USA
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Acute Intermittent Porphyria: Expression of Mutant and Wild-Type Porphobilinogen Deaminase in COS-1 Cells. Mol Med 2000. [DOI: 10.1007/bf03402047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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17
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Affiliation(s)
- S E Mattern
- Mayo Medical School (SETM), and the Division of Hematology and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA
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Gross U, Puy H, Doss M, Robreau AM, Nordmann Y, Doss MO, Deybach JC. New mutations of the hydroxymethylbilane synthase gene in German patients with acute intermittent porphyria. Mol Cell Probes 1999; 13:443-7. [PMID: 10657149 DOI: 10.1006/mcpr.1999.0276] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Acute intermittent porphyria (AIP) is a low-penetrant, autosomal dominant disorder caused by decreased activity of hydroxymethylbilane synthase (HMBS; MIM 176 000), the third enzyme in the heme biosynthetic pathway. We report the first molecular analysis of HMBS gene mutations in classical AIP patients of German origin. The HMBS gene of 5 German AIP patients was analysed by DGGE-screening and direct sequencing of amplified genomic DNA. Five different mutations including four novel mutations were found. Three of them are single base substitutions that affected exon 3 (R16C), exon 10 (V202L), and intron 13 (T to A, IVS13+2) The two remaining mutations are frameshifts which produce a stop codon (del GA in exon 6 and insA in exon 14). These mutations are likely to be responsible for the decrease in HMBS activity found in both erythrocytes and non-erythroid cell lines (lymphocytes). Our results demonstrate the allelic heterogeneity of HMBS mutations in AIP patients of German origin.
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Affiliation(s)
- U Gross
- Division of Clinical Biochemistry, Faculty of Medicine, Marburg, Federal Republic of Germany.
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Petersen NE, Nissen H, Hørder M, Senz J, Jamani A, Schreiber WE. Mutation Screening by Denaturing Gradient Gel Electrophoresis in North American Patients with Acute Intermittent Porphyria. Clin Chem 1998. [DOI: 10.1093/clinchem/44.8.1766] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Niels Erik Petersen
- Department of Clinical Biochemistry and Clinical Genetics, Odense University Hospital, DK-5000 Odense C, Denmark and The Danish Centre of Porphyria
| | - Henrik Nissen
- Department of Clinical Biochemistry and Clinical Genetics, Odense University Hospital, DK-5000 Odense C, Denmark and The Danish Centre of Porphyria
| | - Mogens Hørder
- Department of Clinical Biochemistry and Clinical Genetics, Odense University Hospital, DK-5000 Odense C, Denmark and The Danish Centre of Porphyria
| | - Janine Senz
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, V6T 1W5 Canada
| | - Azim Jamani
- Division of Clinical Chemistry, Vancouver Hospital and Health Sciences Centre, Vancouver, British Columbia, V5Z 1M9 Canada
| | - William E Schreiber
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, V6T 1W5 Canada
- Division of Clinical Chemistry, Vancouver Hospital and Health Sciences Centre, Vancouver, British Columbia, V5Z 1M9 Canada
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