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Riskumäki M, Tessas I, Ottman N, Suomalainen A, Werner P, Karisola P, Lauerma A, Ruokolainen L, Karkman A, Wisgrill L, Sinkko H, Lehtimäki J, Alenius H, Fyhrquist N. Interplay between skin microbiota and immunity in atopic individuals. Allergy 2021; 76:1280-1284. [PMID: 33480030 DOI: 10.1111/all.14744] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/18/2020] [Accepted: 01/18/2021] [Indexed: 12/21/2022]
Affiliation(s)
- Matilda Riskumäki
- Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
- Department of Bacteriology and Immunology Medicum University of Helsinki Helsinki Finland
| | - Ioannis Tessas
- Skin and Allergy Hospital Helsinki University Hospital Helsinki Finland
| | - Noora Ottman
- Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
| | - Alina Suomalainen
- Department of Bacteriology and Immunology Medicum University of Helsinki Helsinki Finland
| | - Paulina Werner
- Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
| | - Piia Karisola
- Department of Bacteriology and Immunology Medicum University of Helsinki Helsinki Finland
| | - Antti Lauerma
- Skin and Allergy Hospital Helsinki University Hospital Helsinki Finland
| | | | - Antti Karkman
- Department of Microbiology University of Helsinki Helsinki Finland
- Helsinki Institute of Sustainability Science (HELSUS) University of Helsinki Helsinki Finland
| | - Lukas Wisgrill
- Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
- Division of Neonatology Pediatric Intensive Care and Neuropediatrics Comprehensive Center for Pediatrics Medical University of Vienna Vienna Austria
| | - Hanna Sinkko
- Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
- Department of Bacteriology and Immunology Medicum University of Helsinki Helsinki Finland
| | | | - Harri Alenius
- Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
- Department of Bacteriology and Immunology Medicum University of Helsinki Helsinki Finland
| | - Nanna Fyhrquist
- Institute of Environmental Medicine Karolinska Institutet Stockholm Sweden
- Department of Bacteriology and Immunology Medicum University of Helsinki Helsinki Finland
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Karisola P, Suomalainen A, Fortino V, Ottman N, Vendelin J, Wolff HJ, Ruokolainen L, Greco D, Fyhrquist N, Alenius H. Tape-stripping alters the microbe-host correlations in mouse skin. Allergy 2019; 74:617-621. [PMID: 30372529 DOI: 10.1111/all.13653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Piia Karisola
- Department of Bacteriology and Immunology; University of Helsinki; Helsinki Finland
| | - Alina Suomalainen
- Department of Bacteriology and Immunology; University of Helsinki; Helsinki Finland
| | - Vittorio Fortino
- Institute of Biomedicine; University of Eastern Finland; Kuopio Finland
- Institute of Biotechnology; University of Helsinki; Helsinki Finland
- Institute of Biosciences and Medical Technologies; BioMediTech; University of Tampere; Tampere Finland
| | - Noora Ottman
- Institute of Environmental Medicine; Karolinska Institutet; Stockholm Sweden
| | | | | | | | - Dario Greco
- Institute of Biotechnology; University of Helsinki; Helsinki Finland
- Institute of Biosciences and Medical Technologies; BioMediTech; University of Tampere; Tampere Finland
- Faculty of Medicine and Life Sciences; University of Tampere; Tampere Finland
| | - Nanna Fyhrquist
- Department of Bacteriology and Immunology; University of Helsinki; Helsinki Finland
- Institute of Environmental Medicine; Karolinska Institutet; Stockholm Sweden
| | - Harri Alenius
- Department of Bacteriology and Immunology; University of Helsinki; Helsinki Finland
- Institute of Environmental Medicine; Karolinska Institutet; Stockholm Sweden
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Berkhout WER, Suomalainen A, Brüllmann D, Jacobs R, Horner K, Stamatakis HC. Justification and good practice in using handheld portable dental X-ray equipment: a position paper prepared by the European Academy of DentoMaxilloFacial Radiology (EADMFR). Dentomaxillofac Radiol 2015; 44:20140343. [PMID: 25710118 DOI: 10.1259/dmfr.20140343] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Handheld portable X-ray devices are increasingly used for intraoral radiography. This development introduces new challenges to staff and patient safety, for which new or revised risk assessments must be made and acted upon prior to use. Major issues might be: difficulties in using rectangular collimation with beam aiming devices, more complex matching of exposure settings to the X-ray receptor used (e.g. longer exposure times), movements owing to the units' weight, protection of the operator and third persons, and the use in uncontrolled environments. These problems may result in violation of the "as low as reasonably achievable'', that is, ALARA principle by an increase in (re)exposures compared with the other available intraoral X-ray devices. Hence, the use of handheld portable X-ray devices should be considered only after careful and documented evaluation (which might be performed based on medical physics support), when there is evidence that handheld operation has benefits over traditional modalities and when no new risks to the operators and/or third parties are caused. It is expected that the use of handheld portable X-ray devices will be very exceptional, and for justified situations only. Special attention should be drawn to beam-aiming devices, rectangular collimation, the section of the X-ray receptor, focus-skin distance, and backscatter shielding, and that the unit delivers reproducible dose over the full set of environmental conditions (e.g. battery status and temperature).
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Affiliation(s)
- W E R Berkhout
- 1 Department of Oral Radiology, Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, Netherlands
| | - A Suomalainen
- 2 Department of Radiology, HUS Medical Imaging Center, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - D Brüllmann
- 3 Department of Oral Surgery, University Medical Center, Mainz, Germany
| | - R Jacobs
- 4 Oral Imaging Center, OMFS-IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, University of Leuven, Leuven, Belgium
| | - K Horner
- 5 School of Dentistry, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - H C Stamatakis
- 6 Department of Orthodontics, University Medical Center of Groningen, Groningen, Netherlands
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Carroll CJ, Brilhante V, Suomalainen A. Next-generation sequencing for mitochondrial disorders. Br J Pharmacol 2014; 171:1837-53. [PMID: 24138576 DOI: 10.1111/bph.12469] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2013] [Revised: 10/03/2013] [Accepted: 10/13/2013] [Indexed: 12/30/2022] Open
Abstract
A great deal of our understanding of mitochondrial function has come from studies of inherited mitochondrial diseases, but still majority of the patients lack molecular diagnosis. Furthermore, effective treatments for mitochondrial disorders do not exist. Development of therapies has been complicated by the fact that the diseases are extremely heterogeneous, and collecting large enough cohorts of similarly affected individuals to assess new therapies properly has been difficult. Next-generation sequencing technologies have in the last few years been shown to be an effective method for the genetic diagnosis of inherited mitochondrial diseases. Here we review the strategies and findings from studies applying next-generation sequencing methods for the genetic diagnosis of mitochondrial disorders. Detailed knowledge of molecular causes also enables collection of homogenous cohorts of patients for therapy trials, and therefore boosts development of intervention.
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Affiliation(s)
- C J Carroll
- Research Programs Unit, Molecular Neurology, Biomedicum-Helsinki, University of Helsinki, Helsinki, Finland
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Fyhrquist N, Ruokolainen L, Suomalainen A, Lehtimäki S, Veckman V, Vendelin J, Karisola P, Lehto M, Savinko T, Jarva H, Kosunen TU, Corander J, Auvinen P, Paulin L, von Hertzen L, Laatikainen T, Mäkelä M, Haahtela T, Greco D, Hanski I, Alenius H. Acinetobacter species in the skin microbiota protect against allergic sensitization and inflammation. J Allergy Clin Immunol 2014; 134:1301-1309.e11. [PMID: 25262465 DOI: 10.1016/j.jaci.2014.07.059] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 07/01/2014] [Accepted: 07/07/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND The human commensal microbiota interacts in a complex manner with the immune system, and the outcome of these interactions might depend on the immune status of the subject. OBJECTIVE Previous studies have suggested a strong allergy-protective effect for Gammaproteobacteria. Here we analyze the skin microbiota, allergic sensitization (atopy), and immune function in a cohort of adolescents, as well as the influence of Acinetobacter species on immune responses in vitro and in vivo. METHODS The skin microbiota of the study subjects was identified by using 16S rRNA sequencing. PBMCs were analyzed for baseline and allergen-stimulated mRNA expression. In in vitro assays human monocyte-derived dendritic cells and primary keratinocytes were incubated with Acinetobacter lwoffii. Finally, in in vivo experiments mice were injected intradermally with A lwoffii during the sensitization phase of the asthma protocol, followed by readout of inflammatory parameters. RESULTS In healthy subjects, but not in atopic ones, the relative abundance of Acinetobacter species was associated with the expression of anti-inflammatory molecules by PBMCs. Moreover, healthy subjects exhibited a robust balance between anti-inflammatory and TH1/TH2 gene expression, which was related to the composition of the skin microbiota. In cell assays and in a mouse model, Acinetobacter species induced strong TH1 and anti-inflammatory responses by immune cells and skin cells and protected against allergic sensitization and lung inflammation through the skin. CONCLUSION These results support the hypothesis that skin commensals play an important role in tuning the balance of TH1, TH2, and anti-inflammatory responses to environmental allergens.
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Affiliation(s)
- Nanna Fyhrquist
- Unit of Systems Toxicology, Finnish Institute of Occupational Health, Helsinki, Finland
| | - Lasse Ruokolainen
- Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Alina Suomalainen
- Unit of Systems Toxicology, Finnish Institute of Occupational Health, Helsinki, Finland
| | - Sari Lehtimäki
- Molecular Immunology Group, Turku Centre for Biotechnology, Turku, Finland
| | - Ville Veckman
- Unit of Systems Toxicology, Finnish Institute of Occupational Health, Helsinki, Finland
| | - Johanna Vendelin
- Unit of Systems Toxicology, Finnish Institute of Occupational Health, Helsinki, Finland
| | - Piia Karisola
- Unit of Systems Toxicology, Finnish Institute of Occupational Health, Helsinki, Finland
| | - Maili Lehto
- Unit of Systems Toxicology, Finnish Institute of Occupational Health, Helsinki, Finland
| | - Terhi Savinko
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Hanna Jarva
- Haartman Institute, Department of Bacteriology and Immunology and Research Programs Unit, Immunobiology, University of Helsinki, and Helsinki University Central Hospital Laboratory (HUSLAB), Helsinki, Finland
| | - Timo U Kosunen
- Haartman Institute, Department of Bacteriology and Immunology and Research Programs Unit, Immunobiology, University of Helsinki, and Helsinki University Central Hospital Laboratory (HUSLAB), Helsinki, Finland
| | - Jukka Corander
- Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
| | - Petri Auvinen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Lars Paulin
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Leena von Hertzen
- Allergy Department, Skin and Allergy Hospital, Helsinki University Hospital, Helsinki, Finland
| | - Tiina Laatikainen
- Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland; Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland
| | - Mika Mäkelä
- Allergy Department, Skin and Allergy Hospital, Helsinki University Hospital, Helsinki, Finland
| | - Tari Haahtela
- Allergy Department, Skin and Allergy Hospital, Helsinki University Hospital, Helsinki, Finland
| | - Dario Greco
- Unit of Systems Toxicology, Finnish Institute of Occupational Health, Helsinki, Finland
| | - Ilkka Hanski
- Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Harri Alenius
- Unit of Systems Toxicology, Finnish Institute of Occupational Health, Helsinki, Finland.
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Heinonen S, Saarinen L, Naukkarinen J, Rodríguez A, Frühbeck G, Hakkarainen A, Lundbom J, Lundbom N, Vuolteenaho K, Moilanen E, Arner P, Hautaniemi S, Suomalainen A, Kaprio J, Rissanen A, Pietiläinen KH. Adipocyte morphology and implications for metabolic derangements in acquired obesity. Int J Obes (Lond) 2014; 38:1423-31. [PMID: 24549139 DOI: 10.1038/ijo.2014.31] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 01/23/2014] [Accepted: 01/27/2014] [Indexed: 11/09/2022]
Abstract
BACKGROUND Adipocyte size and number have been suggested to predict the development of metabolic complications in obesity. However, the genetic and environmental determinants behind this phenomenon remain unclear. METHODS We studied this question in rare-weight discordant (intra-pair difference (Δ) body mass index (BMI) 3-10 kg m(-2), n=15) and concordant (ΔBMI 0-2 kg m(-)(2), n=5) young adult (22-35 years) monozygotic twin pairs identified from 10 birth cohorts of Finnish twins (n=5 500 pairs). Subcutaneous abdominal adipocyte size from surgical biopsies was measured under a light microscope. Adipocyte number was calculated from cell size and total body fat (D × A). RESULTS The concordant pairs were remarkably similar for adipocyte size and number (intra-class correlations 0.91-0.92, P<0.01), suggesting a strong genetic control of these measures. In the discordant pairs, the obese co-twins (BMI 30.6 ± 0.9 kg m(-2)) had significantly larger adipocytes (volume 547 ± 59 pl), than the lean co-twins (24.9 ± 0.9 kg m(-)(2); 356 ± 34 pl, P<0.001). In 8/15 pairs, the obese co-twins had less adipocytes than their co-twins. These hypoplastic obese twins had significantly higher liver fat (spectroscopy), homeostatic model assessment-index, C-reactive protein and low-density lipoprotein cholesterol than their lean co-twins. Hyperplastic obesity was observed in the rest (7/15) of the pairs, obese and lean co-twins having similar metabolic measures. In all pairs, Δadipocyte volume correlated positively and Δcell number correlated negatively with Δhomeostatic model assessment-index and Δlow-density lipoprotein, independent of Δbody fat. Transcripts most significantly correlating with Δadipocyte volume were related to a reduced mitochondrial function, membrane modifications, to DNA damage and cell death. CONCLUSIONS Together, hypertrophy and hypoplasia in acquired obesity are related to metabolic dysfunction, possibly through disturbances in mitochondrial function and increased cell death within the adipose tissue.
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Affiliation(s)
- S Heinonen
- Obesity Research Unit, Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland
| | - L Saarinen
- Research Programs Unit, Genome-Scale Biology and Institute of Biomedicine, Biochemistry and Developmental Biology, Helsinki, Finland
| | - J Naukkarinen
- 1] Obesity Research Unit, Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland [2] FIMM, Institute for Molecular Medicine, University of Helsinki, Helsinki, Finland
| | - A Rodríguez
- Metabolic Research Laboratory, Clinica Universidad de Navarra, & CIBERobn, Instituto de Salud Carlos III, Pamplona, Spain
| | - G Frühbeck
- Metabolic Research Laboratory, Clinica Universidad de Navarra, & CIBERobn, Instituto de Salud Carlos III, Pamplona, Spain
| | - A Hakkarainen
- Helsinki Medical Imaging Center, University of Helsinki, Helsinki, Finland
| | - J Lundbom
- Helsinki Medical Imaging Center, University of Helsinki, Helsinki, Finland
| | - N Lundbom
- Helsinki Medical Imaging Center, University of Helsinki, Helsinki, Finland
| | - K Vuolteenaho
- The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
| | - E Moilanen
- The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, Tampere, Finland
| | - P Arner
- Lipid Laboratory, Department of Medicine, Karolinska University Hospital Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - S Hautaniemi
- Research Programs Unit, Genome-Scale Biology and Institute of Biomedicine, Biochemistry and Developmental Biology, Helsinki, Finland
| | - A Suomalainen
- Research Program of Molecular Neurology and Department of Neurology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - J Kaprio
- 1] FIMM, Institute for Molecular Medicine, University of Helsinki, Helsinki, Finland [2] Finnish Twin Cohort Study, Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki Finland [3] National Institute for Health and Welfare, Department of Mental Health and Substance Abuse Services, Helsinki, Finland
| | - A Rissanen
- Department of Psychiatry, Helsinki University Central Hospital, Helsinki, Finland
| | - K H Pietiläinen
- 1] Obesity Research Unit, Research Programs Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland [2] FIMM, Institute for Molecular Medicine, University of Helsinki, Helsinki, Finland [3] Department of Medicine, Division of Endocrinology, Helsinki University Central Hospital, Helsinki, Finland
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Naukkarinen J, Heinonen S, Hakkarainen A, Lundbom J, Vuolteenaho K, Saarinen L, Hautaniemi S, Rodriguez A, Frühbeck G, Pajunen P, Hyötyläinen T, Orešič M, Moilanen E, Suomalainen A, Lundbom N, Kaprio J, Rissanen A, Pietiläinen KH. Characterising metabolically healthy obesity in weight-discordant monozygotic twins. Diabetologia 2014; 57:167-76. [PMID: 24100782 DOI: 10.1007/s00125-013-3066-y] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Accepted: 09/04/2013] [Indexed: 12/30/2022]
Abstract
AIMS/HYPOTHESIS Not all obese individuals display the metabolic disturbances commonly associated with excess fat accumulation. Mechanisms maintaining this 'metabolically healthy obesity' (MHO) are as yet unknown. We aimed to study different fat depots and transcriptional pathways in subcutaneous adipose tissue (SAT) as related to the MHO phenomenon. METHODS Sixteen rare young adult obesity-discordant monozygotic (MZ) twin pairs (intra-pair difference (∆) in BMI ≥ 3 kg/m(2)), aged 22.8-35.8 years, were examined for detailed characteristics of metabolic health (subcutaneous, intra-abdominal and liver fat [magnetic resonance imaging/spectroscopy]), OGTT, lipids, adipokines and C-reactive protein (CRP). Affymetrix U133 Plus 2.0 chips were used to analyse transcriptomics pathways related to mitochondrial function and inflammation in SAT. RESULTS Based on liver fat accumulation, two metabolically different subgroups emerged. In half (8/16) of the pairs (∆weight 17.1 ± 2.0 kg), the obese co-twin had significantly higher liver fat (∆718%), 78% increase in AUC insulin during OGTT and CRP, significantly more disturbance in the lipid profile and greater tendency for hypertension compared with the lean co-twin. In these obese co-twins, SAT expression of mitochondrial oxidative phosphorylation, branched-chain amino acid catabolism, fatty acid oxidation and adipocyte differentiation pathways were downregulated and chronic inflammation upregulated. In the other eight pairs (∆weight 17.4 ± 2.8 kg), the obese co-twin did not differ from the non-obese co-twin in liver fat (∆8%), insulin sensitivity, CRP, lipids, blood pressure or SAT transcriptomics. CONCLUSIONS/INTERPRETATION Our results suggest that maintenance of high mitochondrial transcription and lack of inflammation in SAT are associated with low liver fat and MHO.
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Affiliation(s)
- J Naukkarinen
- Obesity Research Unit, Research Programs Unit, Diabetes and Obesity, University of Helsinki, Biomedicum Helsinki, C424b, PO Box 63, Helsinki, Finland, 00014
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Hero M, Suomalainen A, Hagström J, Stoor P, Kontio R, Alapulli H, Arte S, Toiviainen-Salo S, Lahdenne P, Mäkitie O. Anti-tumor necrosis factor treatment in cherubism--clinical, radiological and histological findings in two children. Bone 2013; 52:347-53. [PMID: 23069372 DOI: 10.1016/j.bone.2012.10.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 10/03/2012] [Accepted: 10/04/2012] [Indexed: 11/27/2022]
Abstract
Cherubism is a rare and disfiguring genetic disorder with excessive bone resorption and multilocular lesions in the mandible and/or maxilla. The disease-causing gain-of-function mutations in the SH3-binding protein 2 (SH3BP2) gene result in increased myeloid cell responses to macrophage colony stimulating factor and RANK ligand, formation of hyperactive osteoclasts (giant cells), and hyper-reactive macrophages that produce excessive amounts of the inflammatory cytokine tumor necrosis factor α (TNF-α). Recent findings in the cherubism mouse model suggest that TNF-α plays a major role in disease pathogenesis and that removal of TNF-α prevents development of the bone phenotype. We treated two children with cherubism with the TNF-α antagonist adalimumab for approximately 2.5 years and collected extensive clinical, radiological and histological follow-up data during the treatment. Histologically the treatment resulted in a significant reduction in the number of multinucleated giant cells and TNF-α staining positivity in both patients. As evaluated by computed tomography and magnetic resonance imaging, the lesions in Patient 1 showed either moderate enlargement (mandibular symphysis) or remained stable (mandibular rami and body, the maxilla). In Patient 2, the lesions in mandibular symphysis showed enlargement during the first 8 months of treatment, and thereafter the lesions remained unchanged. Bone formation and resorption markers remained unaffected. The treatment was well tolerated. Based on our findings, TNF-α antagonist may decrease the formation of pathogenic giant cells, but does not result in lesion regression or prevent lesion expansion in active cherubism. TNF-α modulator treatment thus does not appear to provide sufficient amelioration for patients suffering from cherubism.
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Affiliation(s)
- M Hero
- Childrens' Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland.
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Abstract
An otherwise healthy 56-year-old Caucasian female was referred to the radiology department because of an ulceration of her palatal mucosa. Clinically the lesion was suspected to be malignant and a multislice CT examination of the head and neck region was performed. This revealed an ulcer-like cavity with no tumour-like contrast enhancement. No relevant bone changes or suspicious lymph nodes of the neck were detected. Based on the multislice CT findings, necrotizing sialometaplasia was suspected and the diagnosis was verified histopathologically. This report describes the CT findings of necrotizing sialometaplasia at the ulceration stage.
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Affiliation(s)
- A Suomalainen
- Department of Radiology, Helsinki University Central Hospital, Finland.
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Robciuc M, Naukkarinen J, Tyynismaa H, Raivio T, Ortega-Alonso A, Suomalainen A, Kaprio J, Rissanen A, Jauhiainen M, Ehnholm C, Pietiläinen K. 155 SERUM LEVELS OF ANGIOPOIETIN-LIKE PROTEIN 4 (ANGPTL4) ARE INVERSELY CORRELATED WITH OBESITY IN HEALTHY YOUNG ADULT TWINS. ATHEROSCLEROSIS SUPP 2011. [DOI: 10.1016/s1567-5688(11)70156-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Isohanni P, Hakonen AH, Euro L, Paetau I, Linnankivi T, Liukkonen E, Wallden T, Luostarinen L, Valanne L, Paetau A, Uusimaa J, Lönnqvist T, Suomalainen A, Pihko H. POLG1 manifestations in childhood. Neurology 2011; 76:811-5. [PMID: 21357833 DOI: 10.1212/wnl.0b013e31820e7b25] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Mitochondrial DNA polymerase γ (POLG1) mutations in children often manifest as Alpers syndrome, whereas in adults, a common manifestation is mitochondrial recessive ataxia syndrome (MIRAS) with severe epilepsy. Because some patients with MIRAS have presented with ataxia or epilepsy already in childhood, we searched for POLG1 mutations in neurologic manifestations in childhood. METHODS We investigated POLG1 in 136 children, all clinically suspected to have mitochondrial disease, with one or more of the following: ataxia, axonal neuropathy, severe epilepsy without known epilepsy syndrome, epileptic encephalopathy, encephalohepatopathy, or neuropathologically verified Alpers syndrome. RESULTS Seven patients had POLG1 mutations, and all of them had severe encephalopathy with intractable epilepsy. Four patients had died after exposure to sodium valproate. Brain MRI showed parieto-occipital or thalamic hyperintense lesions, white matter abnormality, and atrophy. Muscle histology and mitochondrial biochemistry results were normal in all. CONCLUSIONS POLG1 analysis should belong to the first-line DNA diagnostic tests for children with an encephalitis-like presentation evolving into epileptic encephalopathy with liver involvement (Alpers syndrome), even if brain MRI and morphology, respiratory chain activities, and the amount of mitochondrial DNA in the skeletal muscle are normal. POLG1 analysis should precede valproate therapy in pediatric patients with a typical phenotype. However, POLG1 is not a common cause of isolated epilepsy or ataxia in childhood.
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Affiliation(s)
- P Isohanni
- University of Helsinki, Helsinki, Finland.
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Affiliation(s)
- T Lönnqvist
- Division of Child Neurology, Department of Neurology, Helsinki University Central Hospital, Helsinki Medical Imaging Center, University of Helsinki, PO Box 280, FIN-00029 HUCH, Finland.
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Suomalainen A, Kiljunen T, Käser Y, Peltola J, Kortesniemi M. Dosimetry and image quality of four dental cone beam computed tomography scanners compared with multislice computed tomography scanners. Dentomaxillofac Radiol 2009; 38:367-78. [PMID: 19700530 DOI: 10.1259/dmfr/15779208] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES The aim of this study was to evaluate the radiation dose and image quality of four dental cone beam CT (CBCT) scanners, and to compare them with those of two multislice CT (MSCT) scanners. METHODS Tissue doses were measured using a tissue-equivalent anthropomorphic RANDO Head Phantom((R)) with thermoluminescence dosemeters (TLD). An RSVP Head Phantom(TM) with a specially designed cylindrical insert was used for comparison of image quality and absorbed dose. Image quality was evaluated in the form of contrast-to-noise ratio (CNR) and modulation transfer function (MTF). RESULTS Using standard imaging parameters, the effective doses varied between 14 microSv and 269 microSv (International Commission on Radiation Protection (ICRP) 1990) and 27 microSv and 674 microSv (ICRP 2008) with the CBCT scanners, and between 350 microSv and 742 microSv (ICRP 1990) and 685 microSv and 1410 microSv (ICRP 2008) with the MSCT scanners. The CNR of the CBCT and MSCT scanners were 8.2-18.8 and 13.6-20.7, respectively. Low-dose MSCT protocols provided CNRs comparable with those from CBCT scanners. The 10% MTF of the CBCT scanners varied between 0.1 mm(-1) and 0.8 mm(-1), and was 0.5 mm(-1) for all the MSCT protocols examined. CONCLUSIONS CBCT scanners provide adequate image quality for dentomaxillofacial examinations while delivering considerably smaller effective doses to the patient. Large variations in patient dose and image quality emphasize the importance of optimizing imaging parameters in both CBCT and MSCT examinations.
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Affiliation(s)
- A Suomalainen
- Department of Radiology, Helsinki University Central Hospital, Helsinki, Finland.
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Isohanni P, Linnankivi T, Buzkova J, Lonnqvist T, Pihko H, Valanne L, Tienari PJ, Elovaara I, Pirttila T, Reunanen M, Koivisto K, Marjavaara S, Suomalainen A. DARS2 mutations in mitochondrial leucoencephalopathy and multiple sclerosis. J Med Genet 2009; 47:66-70. [DOI: 10.1136/jmg.2009.068221] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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16
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Peltonen LI, Aarnisalo AA, Käser Y, Kortesniemi MK, Robinson S, Suomalainen A, Jero J. Cone-beam computed tomography: a new method for imaging of the temporal bone. Acta Radiol 2009; 50:543-8. [PMID: 19353342 DOI: 10.1080/02841850902839700] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND Clinical cone-beam computed tomography (CBCT), used in diagnostics of dental and maxillofacial radiology for almost 10 years, allows three-dimensional (3D) imaging of a focused area, with reasonable radiation dose. PURPOSE To clarify the applicability of CBCT in imaging of the temporal bone. MATERIAL AND METHODS We imaged cadaver temporal bones, one non-operated and five postmortem operated, with CBCT to evaluate the accuracy of this method in showing clinically important landmarks and the positions of middle-ear implants. In addition, to clarify the imaging protocols for the best possible result, we conducted a contrast-to-noise ratio (CNR) analysis by imaging a specially built phantom insert with different protocols. RESULTS For all the temporal bones, image quality was good and of diagnostic value, and the surgical landmarks as well as positions and details of the implants could be accurately observed. Based on measurements conducted with the phantom, the best possible clarity of the images with the machine used (3D Accuitomo; Morita Co., Kyoto, Japan) was achieved with a tube voltage of 80 kVp and a current of 4 mA. CONCLUSION Cone-beam CT is a promising new method for otologic imaging, based on its accuracy and relatively low radiation exposure per investigation.
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Affiliation(s)
- L. I. Peltonen
- Department of Otorhinolaryngology, Helsinki University Central Hospital, Helsinki, Finland
| | - A. A. Aarnisalo
- Department of Otorhinolaryngology, Helsinki University Central Hospital, Helsinki, Finland
| | - Y. Käser
- HUS Helsinki Medical Imaging Center, University of Helsinki, Helsinki, Finland
- Department of Radiology, Helsinki University Central Hospital, Helsinki, Finland
| | - M. K. Kortesniemi
- HUS Helsinki Medical Imaging Center, University of Helsinki, Helsinki, Finland
- Department of Radiology, Helsinki University Central Hospital, Helsinki, Finland
| | - S. Robinson
- Department of Radiology, Helsinki University Central Hospital, Helsinki, Finland
- Diagnose Zentrum Urania, Vienna, Austria
| | - A. Suomalainen
- Department of Radiology, Helsinki University Central Hospital, Helsinki, Finland
| | - J. Jero
- Department of Otorhinolaryngology, Helsinki University Central Hospital, Helsinki, Finland
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17
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18
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Hakonen AH, Goffart S, Marjavaara S, Paetau A, Cooper H, Mattila K, Lampinen M, Sajantila A, Lonnqvist T, Spelbrink JN, Suomalainen A. Infantile-onset spinocerebellar ataxia and mitochondrial recessive ataxia syndrome are associated with neuronal complex I defect and mtDNA depletion. Hum Mol Genet 2008; 17:3822-35. [DOI: 10.1093/hmg/ddn280] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Suomalainen A, Vehmas T, Kortesniemi M, Robinson S, Peltola J. Accuracy of linear measurements using dental cone beam and conventional multislice computed tomography. Dentomaxillofac Radiol 2008; 37:10-7. [PMID: 18195249 DOI: 10.1259/dmfr/14140281] [Citation(s) in RCA: 150] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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20
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Luoma PT, Eerola J, Ahola S, Hakonen AH, Hellström O, Kivistö KT, Tienari PJ, Suomalainen A. Mitochondrial DNA polymerase gamma variants in idiopathic sporadic Parkinson disease. Neurology 2007; 69:1152-9. [PMID: 17846414 DOI: 10.1212/01.wnl.0000276955.23735.eb] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Dysfunction of mitochondrial DNA polymerase gamma (POLG) has been recently recognized as an important cause of inherited neurodegenerative diseases. We have reported dominant and recessive inheritance of parkinsonism, mitochondrial myopathy, and premature amenorrhea in five ethnically distinct families with POLG1 mutations. This prompted us to carry out a detailed analysis of the coding region and intron-exon boundaries of POLG1 in Finnish patients with idiopathic sporadic Parkinson disease (PD) and in nonparkinsonian controls. METHODS The coding region of POLG1 was analyzed in 140 Finnish patients with PD and their 127 spouses as age- and ethnically matched controls. Further, we analyzed the intragenic CAG-repeat region of POLG1 in 126 additional patients with nonparkinsonian neurologic disorders and in 516 Finnish population controls. RESULTS We found clustering of rare variants of the POLG1 CAG-repeat, encoding a polyglutamine tract, in Finnish patients with idiopathic PD as compared to their spouses (p = 0.003; OR 3.01, 95% CI 1.35 to 6.71), population controls (p = 0.001; OR 2.45, 95% CI 1.45 to 4.14), and patients with nonparkinsonian neurologic disorders (p = 0.05, OR 1.98, 95% CI 0.97 to 4.05). We found several amino acid substitutions, none of them associating with PD. These included a previously parkinsonism-associated POLG variant Y831C, found in one patient with PD, but also in five controls, suggesting that it is a neutral amino acid polymorphism. CONCLUSIONS Our results suggest that POLG polyglutamine tract variants should be considered as a predisposing genetic factor in idiopathic sporadic Parkinson disease.
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Affiliation(s)
- P T Luoma
- Research Program of Molecular Neurology, Biomedicum-Helsinki, Helsinki University, Helsinki, Finland
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21
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Isohanni P, Götz A, Marjavaara S, Paetau A, Herva R, Suomalainen A, Pihko H. M.P.1.10 Mitochondrial myopathy caused by thymidine kinase 2 (TK2) mutation mimics congenital muscular dystrophy. Neuromuscul Disord 2007. [DOI: 10.1016/j.nmd.2007.06.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
Mitochondrial recessive ataxia syndrome (MIRAS) is a common cause of autosomal recessive juvenile- or adult-onset ataxia, at least in Scandinavia. MIRAS patients are homozygous or compound heterozygous for POLG mutations W748S and A467T. Because many first-degree relatives of MIRAS patients in the studied families have reported neurological symptoms and some recent studies have suggested dominant negative effect of these mutations, a careful family study of heterozygotes was needed. We investigated all available members of the original large MIRAS family with W748S mutation. Neurological symptoms and signs were present in a number of carriers, but clearly defined neurological diseases did not segregate consistently with the mutation. Sensory polyneuropathy as a subclinical finding was observed in the majority of carriers examined. By positron emission tomography, cerebral glucose metabolism was moderately reduced in two out of four heterozygotes compared with severe reduction in one MIRAS patient. In conclusion, W748S heterozygotes showed no clinically manifesting phenotype.
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Affiliation(s)
- M Rantamäki
- Department of Physical Medicine and Rehabilitation, Seinäjoki Central Hospital, Seinäjoki, Finland.
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23
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Hakonen AH, Isohanni P, Paetau A, Herva R, Suomalainen A, Lonnqvist T. Recessive Twinkle mutations in early onset encephalopathy with mtDNA depletion. Brain 2007; 130:3032-40. [DOI: 10.1093/brain/awm242] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Peltonen LI, Aarnisalo AA, Kortesniemi MK, Suomalainen A, Jero J, Robinson S. Limited cone-beam computed tomography imaging of the middle ear: a comparison with multislice helical computed tomography. Acta Radiol 2007; 48:207-12. [PMID: 17354143 DOI: 10.1080/02841850601080465] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To determine the applicability of cone-beam computed tomography (CBCT) in otological imaging, and to compare its accuracy with the routinely used multislice helical CT (MSCT) for imaging of the middle- and inner-ear areas. MATERIAL AND METHODS Thirteen unoperated human cadaver temporal bones were imaged with CBCT and MSCT. Sixteen landmarks of the middle and adjacent inner ear were evaluated and compared for their conspicuity according to a modified Likert scale. Total scores and scores for subgroups including landmarks of specific clinical interest were also compared. RESULTS No significant differences were found between the imaging techniques or subgroups when scores of individual structures were compared. While the middle ear itself was visible in all cases with CBCT, parts of the inner ear were "cut off" in four cases due to the limited field of view. For the same reason, the evaluation of the whole mastoid was not possible with CBCT. The cochlear and vestibular aqueducts were not visualized in either CT techniques. The contrast-to-noise ratio was more than 50% lower in CBCT than in MSCT, but still adequate for diagnostic task. CONCLUSION CBCT proved to be at least as accurate as routinely used MSCT in revealing the clinically and surgically important middle-ear structures. The results show that high-quality imaging of the middle ear is possible with the current CBCT device.
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Affiliation(s)
- L I Peltonen
- Department of Otorhinolaryngology, Helsinki University Central Hospital, Helsinki, Finland
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25
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Rostedt Punga A, Ahlqvist K, Bartoccioni E, Scuderi F, Marino M, Suomalainen A, Kalimo H, Stålberg EV. Neurophysiological and mitochondrial abnormalities in MuSK antibody seropositive myasthenia gravis compared to other immunological subtypes. Clin Neurophysiol 2006; 117:1434-43. [PMID: 16737845 DOI: 10.1016/j.clinph.2006.03.028] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 03/21/2006] [Accepted: 03/30/2006] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To compare the electrophysiological and histopathological features of immunological myasthenia gravis (MG) subtypes. METHODS Fifty MG patients underwent clinical examination, MuSK-Ab and AChR-Ab analysis. The majority underwent quantitative and single-fiber electromyography (QEMG, SFEMG), repetitive nerve stimulation and deltoid muscle biopsy. From muscle specimens with histological mitochondrial dysfunction, we amplified mitochondrial DNA (mtDNA). In specimens with mtDNA deletions, the nuclear gene POLG1 was sequenced. RESULTS Five AChR-Ab seropositive [AChR(+)] and 5 seronegative [AChR(-)] patients were MuSK-Ab seropositive [MuSK(+)]. Five of 7 neurophysiologically examined MuSK(+) patients (71%) had proximal myopathic pattern, compared to 7 of 31 MuSK(-)/AChR(+) patients (23%) (P=0.012). SFEMG was abnormal in all examined MuSK(+) patients. All 7 biopsied MuSK(+) and 32 MuSK(-) patients (89%) had cytochrome c oxidase (COX) negative fibers. Three of five MuSK(+) and 13 of 20 MuSK(-) patients analyzed had multiple mtDNA deletions but no POLG1 mutations. CONCLUSIONS Similar degree of SFEMG abnormalities was present in proximal muscles among MuSK(+) and AChR(+) patients. Proximal myopathy was over-represented in MuSK(+) patients; however, both MuSK(+) and MuSK(-) patients had mild myopathy with frequent mitochondrial abnormalities. SIGNIFICANCE The weakness in MuSK(+) patients is most likely due to disturbed neuromuscular transmission. The frequently encountered mitochondrial dysfunction in MG warrants further study.
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Affiliation(s)
- A Rostedt Punga
- Department of Clinical Neurophysiology, University Hospital, S-75185 Uppsala, Sweden.
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26
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Van Goethem G, Luoma P, Rantamäki M, Al Memar A, Kaakkola S, Hackman P, Krahe R, Löfgren A, Martin JJ, De Jonghe P, Suomalainen A, Udd B, Van Broeckhoven C. POLG mutations in neurodegenerative disorders with ataxia but no muscle involvement. Neurology 2005; 63:1251-7. [PMID: 15477547 DOI: 10.1212/01.wnl.0000140494.58732.83] [Citation(s) in RCA: 200] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
OBJECTIVE To identify POLG mutations in patients with sensory ataxia and CNS features. METHODS The authors characterized clinical, laboratory, and molecular genetic features in eight patients from five European families. The authors conducted sequencing of coding exons of POLG, C10orf2 (Twinkle), and ANT1 and analyzed muscle mitochondrial DNA (mtDNA), including Southern blot analysis and long-range PCR. RESULTS Ataxia occurred in combination with various CNS features, including myoclonus, epilepsy, cognitive decline, nystagmus, dysarthria, thalamic and cerebellar white matter lesions on MRI, and neuronal loss in discrete gray nuclei on autopsy. Gastrointestinal dysmotility, weight loss, cardiomyopathy, and valproate-induced hepatotoxicity occurred less frequently. Two patients died without preceding signs of progressive external ophthalmoplegia. In muscle, typical findings of mitochondrial disease, such as ragged red fibers and Southern blot mtDNA abnormalities, were absent. POLG mutations were present in eight patients, including two isolated cases, and one Finnish and two unrelated Belgian families contained in total six patients. All POLG mutations were recessive, occurring in a homozygous state in seven patients and in a compound heterozygous state in one patient. The novel W748S mutation was identified in five patients from three unrelated families. CONCLUSIONS The clinical spectrum of recessive POLG mutations is expanded by sensory ataxic neuropathy, combined with variable features of involvement of CNS and other organs. Progressive external ophthalmoplegia, myopathy, ragged red fibers, and Southern blot abnormalities of muscle mitochondrial DNA also are not mandatory features associated with POLG mutations.
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Affiliation(s)
- G Van Goethem
- Division of Neurology and the Neuromuscular Reference Center, University Hospital, Antwerpen, Belgium.
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27
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Suomalainen A, Salo A, Robinson S. The 3DX multi-image micro-CT device in clinical dental practice. Int J Oral Maxillofac Surg 2005. [DOI: 10.1016/s0901-5027(05)81394-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kiechl S, Horváth R, Luoma P, Kiechl-Kohlendorfer U, Wallacher-Scholz B, Stucka R, Thaler C, Wanschitz J, Suomalainen A, Jaksch M, Willeit J. Two families with autosomal dominant progressive external ophthalmoplegia. J Neurol Neurosurg Psychiatry 2004; 75:1125-8. [PMID: 15258213 PMCID: PMC1739155 DOI: 10.1136/jnnp.2003.025890] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES We report here the clinical and genetic features of two new families with autosomal dominant progressive external ophthalmoplegia (adPEO). PATIENTS AND METHODS The examination of index patients included a detailed clinical characterisation, histological analysis of muscle biopsy specimens, and genetic testing of mitochondrial and nuclear DNA extracted from muscle and leucocytes. RESULTS Index patients in both families presented with PEO and developed other clinical disease manifestations, such as myopathy and cardiomyopathy (patient 1) and axonal neuropathy, diabetes mellitus, hearing loss, and myopathy (patient 2), later in the course of illness. Both patients had ragged red fibres on muscle histology. Southern blot of mtDNA from muscle of patient 2 showed multiple deletions. In this case, a novel heterozygous missense mutation F485L was identified in the nuclear encoded putative mitochondrial helicase Twinkle. The mutation co-segregated with the clinical phenotype in the family and was not detected in 150 control chromosomes. In the other index patient, sequencing of ANT1, C10orf2 (encoding for Twinkle), and POLG1 did not reveal pathogenic mutations. CONCLUSIONS Our cases illustrate the clinical variability of adPEO, add a novel pathogenic mutation in Twinkle (F485L) to the growing list of genetic abnormalities in adPEO, and reinforce the relevance of other yet unidentified genes in mtDNA maintenance and pathogenesis of adPEO.
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Affiliation(s)
- S Kiechl
- Department of Neurology, University Hospital Innsbruck, Austria.
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29
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Affiliation(s)
- A Suomalainen
- Department of Human Molecular Genetics, National Public Health Institute, Helsinki, Finland
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30
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Abstract
Diseases caused by nuclear genes that affect mitochondrial DNA (mtDNA) stability are an interesting group of mitochondrial disorders, involving both cellular genomes. In these disorders, a primary nuclear gene defect causes secondary mtDNA loss or deletion formation, which leads to tissue dysfunction. Therefore, the diseases clinically resemble those caused by mtDNA mutations, but follow a Mendelian inheritance pattern. Several clinical entities associated with multiple mtDNA deletions have been characterized, the most frequently described being autosomal dominant progressive external ophthalmoplegia (adPEO). MtDNA depletion syndrome (MDS) is a severe disease of childhood, in which tissue-specific loss of mtDNA is seen. Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) patients may have multiple mtDNA deletions and/or mtDNA depletion. Recent reports of thymidine phosphorylase mutations in MNGIE and adenine nucleotide translocator mutations in adPEO have given new insights into the mechanisms of mtDNA maintenance in mammals. The common mechanism underlying both of these gene defects could be disturbed mitochondrial nucleoside pools, the building blocks of mtDNA. Future studies on MNGIE and adPEO pathogenesis, and identification of additional gene defects in adPEO and MDS will provide further understanding about the mammalian mtDNA maintenance and the crosstalk between the nuclear and mitochondrial genomes.
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Affiliation(s)
- A Suomalainen
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
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Löfberg M, Lindholm H, Näveri H, Majander A, Suomalainen A, Paetau A, Sovijärvi A, Härkönen M, Somer H. ATP, phosphocreatine and lactate in exercising muscle in mitochondrial disease and McArdle's disease. Neuromuscul Disord 2001; 11:370-5. [PMID: 11369188 DOI: 10.1016/s0960-8966(00)00205-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We studied exercise-induced changes in the adenosine triphosphate (ATP), phosphocreatine (PCr), and lactate levels in the skeletal muscle of mitochondrial patients and patients with McArdle's disease. Needle muscle biopsy specimens for biochemical measurement were obtained before and immediately after maximal short-term bicycle exercise test from 12 patients suffering from autosomal dominant and recessive forms of progressive external ophthalmoplegia and multiple deletions of mitochondrial DNA (adPEO, arPEO, respectively), five patients with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) 3243 A-->G point mutation, and four patients with McArdle's disease. Muscle ATP and PCr levels at rest or after exercise did not differ significantly from those of the controls in any patient group. In patients with mitochondrial disease, muscle lactate tended to be lower at rest and increase more during exercise than in controls, the most remarkable rise being measured in patients with adPEO with generalized muscle symptoms and in patients with MELAS point mutation. In McArdle patients, the muscle lactate level decreased during exercise. No correlation was found between the muscle ATP and PCr levels and the respiratory chain enzyme activity.
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Affiliation(s)
- M Löfberg
- Institute of Neurosciences, Department of Neurology, Helsinki University Hospital, 00029 HUS, Helsinki, Finland.
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Spelbrink JN, Li FY, Tiranti V, Nikali K, Yuan QP, Tariq M, Wanrooij S, Garrido N, Comi G, Morandi L, Santoro L, Toscano A, Fabrizi GM, Somer H, Croxen R, Beeson D, Poulton J, Suomalainen A, Jacobs HT, Zeviani M, Larsson C. Human mitochondrial DNA deletions associated with mutations in the gene encoding Twinkle, a phage T7 gene 4-like protein localized in mitochondria. Nat Genet 2001; 28:223-31. [PMID: 11431692 DOI: 10.1038/90058] [Citation(s) in RCA: 597] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The gene products involved in mammalian mitochondrial DNA (mtDNA) maintenance and organization remain largely unknown. We report here a novel mitochondrial protein, Twinkle, with structural similarity to phage T7 gene 4 primase/helicase and other hexameric ring helicases. Twinkle colocalizes with mtDNA in mitochondrial nucleoids. Screening of the gene encoding Twinkle in individuals with autosomal dominant progressive external ophthalmoplegia (adPEO), associated with multiple mtDNA deletions, identified 11 different coding-region mutations co-segregating with the disorder in 12 adPEO pedigrees of various ethnic origins. The mutations cluster in a region of the protein proposed to be involved in subunit interactions. The function of Twinkle is inferred to be critical for lifetime maintenance of human mtDNA integrity.
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Affiliation(s)
- J N Spelbrink
- Institute of Medical Technology & Tampere University Hospital, Tampere, Finland.
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Li FY, Nikali K, Gregan J, Leibiger I, Leibiger B, Schweyen R, Larsson C, Suomalainen A. Characterization of a novel human putative mitochondrial transporter homologous to the yeast mitochondrial RNA splicing proteins 3 and 4. FEBS Lett 2001; 494:79-84. [PMID: 11297739 DOI: 10.1016/s0014-5793(01)02319-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We report here a novel human gene, hMRS3/4, encoding a putative mitochondrial transporter structurally and functionally homologous to the yeast mitochondrial RNA splicing proteins 3 and 4. These proteins belong to the family of mitochondrial carrier proteins (MCF) and are likely to function as solute carriers. hMRS3/4 spans approximately 10 kb of genomic DNA on chromosome 10q24 and consists of four exons that encode a 364-aa protein with six transmembrane domains. A putative splice variant, encoding a 177-aa protein with three transmembrane domains, was also identified. hMRS3/4 has a well-conserved signature sequence of MCF and is targeted into the mitochondria. When expressed in yeast, hMRS3/4 efficiently restores the mitochondrial functions in mrs3(o)mrs4(o) knock-out mutants. Ubiquitous expression in human tissues and a well-conserved structure and function suggest an important role for hMRS3/4 in human cells.
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Affiliation(s)
- F Y Li
- Department of Molecular Medicine, CMM, Karolinska Hospital, Stockholm, Sweden.
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Rahman S, Poulton J, Marchington D, Suomalainen A. Decrease of 3243 A-->G mtDNA mutation from blood in MELAS syndrome: a longitudinal study. Am J Hum Genet 2001; 68:238-40. [PMID: 11085913 PMCID: PMC1234919 DOI: 10.1086/316930] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2000] [Accepted: 11/06/2000] [Indexed: 12/25/2022] Open
Abstract
It is widely held that changes in the distribution of mutant mtDNAs underlie the progressive nature of mtDNA diseases, but there are few data documenting such changes. We compared the levels of 3243 A-->G mutant mtDNA in blood at birth from Guthrie cards and at the time of diagnosis in a blood DNA sample from patients with mitochondrial encephalopathy, lactic acidosis, and strokelike episodes (MELAS) syndrome. Paired blood DNA samples separated by 9-19 years were obtained from six patients with MELAS. Quantification of mutant load, by means of a solid-phase minisequencing technique, demonstrated a decline (range 12%-29%) in the proportion of mutant mtDNA in all cases (P=.0015, paired t-test). These results suggest that mutant mtDNA is slowly selected from rapidly dividing blood cells in MELAS.
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Affiliation(s)
- S Rahman
- Metabolic Unit, Institute of Child Health, London, United Kingdom
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35
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Kaukonen J, Juselius JK, Tiranti V, Kyttälä A, Zeviani M, Comi GP, Keränen S, Peltonen L, Suomalainen A. Role of adenine nucleotide translocator 1 in mtDNA maintenance. Science 2000; 289:782-5. [PMID: 10926541 DOI: 10.1126/science.289.5480.782] [Citation(s) in RCA: 415] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Autosomal dominant progressive external ophthalmoplegia is a rare human disease that shows a Mendelian inheritance pattern, but is characterized by large-scale mitochondrial DNA (mtDNA) deletions. We have identified two heterozygous missense mutations in the nuclear gene encoding the heart/skeletal muscle isoform of the adenine nucleotide translocator (ANT1) in five families and one sporadic patient. The familial mutation substitutes a proline for a highly conserved alanine at position 114 in the ANT1 protein. The analogous mutation in yeast caused a respiratory defect. These results indicate that ANT has a role in mtDNA maintenance and that a mitochondrial disease can be caused by a dominant mechanism.
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MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution
- Animals
- DNA, Mitochondrial/genetics
- DNA, Mitochondrial/metabolism
- Female
- Founder Effect
- Genes, Dominant
- Humans
- Isoenzymes/chemistry
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Italy
- Male
- Mitochondrial ADP, ATP Translocases/chemistry
- Mitochondrial ADP, ATP Translocases/genetics
- Mitochondrial ADP, ATP Translocases/metabolism
- Molecular Sequence Data
- Mutation, Missense
- Ophthalmoplegia, Chronic Progressive External/enzymology
- Ophthalmoplegia, Chronic Progressive External/genetics
- Oxygen Consumption
- Pedigree
- Point Mutation
- Saccharomyces cerevisiae/enzymology
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
- Sequence Deletion
- Transformation, Genetic
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Affiliation(s)
- J Kaukonen
- National Public Health Institute, Department of Human Molecular Genetics, Mannerheimintie 166, 00300 Helsinki, Finland
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Abstract
Reliable quantification by PCR requires careful experimental design and conditions, often involving sampling of the PCR reactions at different time points or amplifying multiple dilutions of a standard DNA. We describe here an accurate, quantitative and easily automatizable solid-phase method based on competitive PCR. The PCR products are analyzed by solid-phase mini-sequencing after capture of biotinylated PCR products in streptavidin-coated microtiter wells and single-nucleotide extension of a specific detection primer by a radioactively labelled nucleotide. The results are expressed as numeric cpm-values, and the incorporated label expresses the relative amount of sequence variants in the original template mixture. We have applied the method to determination of allele frequencies in pooled DNA samples, of mitochondrial heteroplasmy, of gene copy numbers, and to forensic DNA analysis.
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Affiliation(s)
- A Suomalainen
- Department of Medical Science, Uppsala University, Sweden
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Kaukonen J, Zeviani M, Comi GP, Piscaglia MG, Peltonen L, Suomalainen A. A third locus predisposing to multiple deletions of mtDNA in autosomal dominant progressive external ophthalmoplegia. Am J Hum Genet 1999; 65:256-61. [PMID: 10364542 PMCID: PMC1378100 DOI: 10.1086/302445] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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38
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Rovio A, Tiranti V, Bednarz AL, Suomalainen A, Spelbrink JN, Lecrenier N, Melberg A, Zeviani M, Poulton J, Foury F, Jacobs HT. Analysis of the trinucleotide CAG repeat from the human mitochondrial DNA polymerase gene in healthy and diseased individuals. Eur J Hum Genet 1999; 7:140-6. [PMID: 10196696 DOI: 10.1038/sj.ejhg.5200244] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The human nuclear gene (POLG) for the catalytic subunit of mitochondrial DNA polymerase (DNA polymerase gamma) contains a trinucleotide CAG microsatellite repeat within the coding sequence. We have investigated the frequency of different repeat-length alleles in populations of diseased and healthy individuals. The predominant allele of 10 CAG repeats was found at a very similar frequency (approximately 88%) in both Finnish and ethnically mixed population samples, with homozygosity close to the equilibrium prediction. Other alleles of between 5 and 13 repeat units were detected, but no larger, expanded alleles were found. A series of 51 British myotonic dystrophy patients showed no significant variation from controls, indicating an absence of generalised CAG repeat instability. Patients with a variety of molecular lesions in mtDNA, including sporadic, clonal deletions, maternally inherited point mutations, autosomally transmitted mtDNA depletion and autosomal dominant multiple deletions showed no differences in POLG trinucleotide repeat-length distribution from controls. These findings rule out POLG repeat expansion as a common pathogenic mechanism in disorders characterised by mitochondrial genome instability.
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Affiliation(s)
- A Rovio
- Institute of Medical Technology, University of Tampere, Finland
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39
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Suomalainen A, Syvänen AC. Quantitative analysis of human DNA sequences by PCR and solid-phase minisequencing. Methods Mol Med 1999; 26:233-244. [PMID: 21340881 DOI: 10.1385/0-89603-518-2:233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The PCR technique provides highly specific and sensitive means for analyzing nucleic acids, but it does not allow their direct quantification. This limitation originates from the fact that the efficiency of PCR depends on the amount of template sequence present in the sample, and the amplification is exponential only at low template concentrations (1). Because of this "plateau effect" of the PCR, the amount of the amplification product does not directly reflect the original amount of the template. Moreover, subtle differences in the reaction conditions, such as material from biological samples, might cause significant sample to sample variation in the final yield of the PCR product.
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Affiliation(s)
- A Suomalainen
- Department of Human Molecular Genetics, National Public Health Institute, Helsinki, Finland
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40
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Järvinen N, Mäkelä-Bengs P, Suomalainen A, Vuopala K, Herva R, Palotie A, Peltonen L. LCCS: a lethal motoneuron disease of the fetus maps to chromosome 9q34. Ann N Y Acad Sci 1998; 857:260-2. [PMID: 9917852 DOI: 10.1111/j.1749-6632.1998.tb10127.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- N Järvinen
- Department of Human Molecular Genetics, University of Helsinki, Finland.
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41
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Mäkelä-Bengs P, Järvinen N, Vuopala K, Suomalainen A, Ignatius J, Sipilä M, Herva R, Palotie A, Peltonen L. Assignment of the disease locus for lethal congenital contracture syndrome to a restricted region of chromosome 9q34, by genome scan using five affected individuals. Am J Hum Genet 1998; 63:506-16. [PMID: 9683599 PMCID: PMC1377309 DOI: 10.1086/301968] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Lethal congenital contracture syndrome (LCCS) is an autosomal recessive disease leading to death before the 32d gestational week. It is characterized by the fetal akinesia phenotype, with highly focused degeneration of motoneurons in the spinal cord as the main neuropathological finding. We report here the assignment of the LCCS locus to a defined region of chromosome 9q34, between markers D9S1825 and D9S1830. The initial genome scan was performed with the DNA samples of only five affected individuals from two unrelated LCCS families. The conventional linkage analysis performed with 20 affected individuals and their families was focused on those chromosomal regions in which the affected siblings were identical by descent in the initial scan. One core haplotype of 3 cM was observed in LCCS alleles, supporting the assumption of one major mutation underlying LCCS, and linkage disequilibrium analysis restricted the critical chromosomal region to <100 kb in the vicinity of marker D9S61. Two genes, NGAL (neutrophil gelatinase-associated lipocalin and NOTCH 1, were excluded as causative genes for LCCS
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Affiliation(s)
- P Mäkelä-Bengs
- Department of Human Molecular Genetics, National Public Health Institute, helsinki, Finland
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42
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Affiliation(s)
- A Suomalainen
- National Public Health Institute, Department of Human Molecular Genetics, Helsinki, Finland
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43
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Valanne L, Ketonen L, Majander A, Suomalainen A, Pihko H. Neuroradiologic findings in children with mitochondrial disorders. AJNR Am J Neuroradiol 1998; 19:369-77. [PMID: 9504497 PMCID: PMC8338166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE We report the neuroradiologic findings in 25 children with various mitochondrial diseases. METHODS Twenty-two children with a mitochondrial disorder had MR imaging of the brain and three children had CT studies. In all cases, the diagnosis was based on examination of muscle morphology, analysis of oxygen consumption and respiratory chain enzyme activity in isolated muscle mitochondria, and analysis of rearrangements of the mitochondrial DNA. RESULTS Fifteen patients were found to have the classical syndromes of mitochondrial diseases. Four children had Kearns-Sayre syndrome, but only one had the typical neuroradiologic findings of basal ganglia and brain stem lesions, T2 hyperintensity of the cerebral white matter, and cerebellar atrophy; the others had nonspecific or normal findings. Eight patients had Leigh syndrome, and all showed changes in the putamina. Involvement of the caudate nuclei, globus pallidi, thalami, and brain stem was common, and diffuse supratentorial white matter T2 hyperintensity was seen in two of these patients. Three patients had mitochondrial encephalopathy with lactic acidosis and strokelike episodes (MELAS), with infarctlike lesions that did not correspond to the vascular territories. Ten children with complex I or IV deficiencies and abnormal muscle morphology had nonspecific imaging findings, such as atrophy and abnormal or delayed myelination. One patient with combined complex I and IV deficiency had extensive white matter changes. None of the patients with clinical encephalopathy had normal findings. CONCLUSION MR imaging is helpful in the diagnosis of the classical mitochondrial diseases; however, nonspecific findings are common.
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Affiliation(s)
- L Valanne
- Department of Radiology, Hospital for Children and Adolescents, Helsinki, Finland
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44
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Klimek A, Suomalainen A, Bratosiewicz J, Niewinowska-Rupf K, Bogucki A, Liberski PP. A case of mitochondrial myopathy with MELAS-like features and polyneuropathy: ultrastructural and molecular studies. POL J PATHOL 1997; 48:197-200. [PMID: 9401413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- A Klimek
- Department of Neurology, Regional Copernicus Hospital, Lódź
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45
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Mustajoki S, Kauppinen R, Mustajoki P, Suomalainen A, Peltonen L. Steady-state transcript levels of the porphobilinogen deaminase gene in patients with acute intermittent porphyria. Genome Res 1997; 7:1054-60. [PMID: 9371741 DOI: 10.1101/gr.7.11.1054] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PCR-based solid-phase minisequencing method was used to analyze the steady-state mRNA levels of the porphobilinogen deaminase gene in eight patients with acute intermittent porphyria. The patients had the earlier characterized mutations 517C --> T (R173W), 518G --> A (R173Q), 673C --> G (R225G), 673C --> T (R225X), 713T --> G (L278P), and 1073delA (frame shift). All mutations, except the missense mutation 517C --> T in exon 10, affected the steady-state transcript levels of the mutant allele. The mutant mRNA levels in lymphocytes varied from 5% to 95% of the corresponding wild-type allele levels. In contrast to the CRIM-negative mutation 517C --> T, the CRIM-positive mutation in the same codon 518G --> A resulted in reduction of the steady-state transcript level of the mutant allele to 65% of that of the normal allele. The two mutations, 673C --> G or T, affecting the same nucleotide in exon 12 also differed considerably in their effect on mRNA levels: The transcript level of the allele with a missense mutation was decreased to 80% of that of the normal allele, whereas a nonsense mutation at the same position resulted in a dramatic decrease (fivefold) in the levels of the mutant transcript. Our data showed large variations between the levels of mutant transcript in AIP patients and these variations did not correlate either to CRIM class, to the location of the disease causing mutation in the PBGD gene, or to the clinical phenotype of AIP.
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Affiliation(s)
- S Mustajoki
- Department of Medicine, Division of Endocrinology, Helsinki University Central Hospital, FIN-00290 Helsinki, Finland.
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Somer H, Kaukonen J, Leinonen H, Löfberg M, Paetau A, Majander A, Suomalainen A. 1-29-13 Progressive external ophthalmoplegia associated with multiple deletions of mitochondrial DNA: A family with possible autosomal recessive inheritance. J Neurol Sci 1997. [DOI: 10.1016/s0022-510x(97)85033-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
Mitochondrial diseases are a group of disorders characterized by morphological or functional defects of the mitochondria, the organelles producing most of our cellular energy. As the only extranuclear site carrying genetic information, the mitochondria add an important chapter into the inheritance patterns of genetic diseases. Mitochondrial DNA (mtDNA) is exclusively maternally inherited in humans, but a mitochondrial disorder may follow either maternal or Mendelian inheritance, depending on the site of the primary gene defect. After the initial finding of mtDNA mutations in rare ocular myopathies in 1988, an explosion in the amount of information on mitochondrial diseases has occurred. Because the mitochondria produce energy in all the tissues, symptoms resulting from mtDNA mutations may originate from any organ system, and the clinical spectrum of mitochondrial diseases has expanded to virtually all branches of medicine. Subgroups of several common diseases, such as diabetes, deafness and inherited cardiomyopathies, have been found to be caused by mtDNA mutations, and some mtDNA defects have been suggested to modify the outcome of diseases primarily caused by other factors, such as Parkinson's or Alzheimer's disease. Although no breakthroughs in the therapeutic trials on the devastating mitochondrial diseases have so far been achieved, detection of mtDNA mutations offers an accurate diagnosis and is a prerequisite for genetic counselling, being now accessible to most clinicians.
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Affiliation(s)
- A Suomalainen
- National Public Health Institute, Department of Human Molecular Genetics, Helsinki, Finland.
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48
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Suomalainen A, Majander A, Wallin M, Setälä K, Kontula K, Leinonen H, Salmi T, Paetau A, Haltia M, Valanne L, Lonnqvist J, Peltonen L, Somer H. Autosomal dominant progressive external ophthalmoplegia with multiple deletions of mtDNA: clinical, biochemical, and molecular genetic features of the 10q-linked disease. Neurology 1997; 48:1244-53. [PMID: 9153451 DOI: 10.1212/wnl.48.5.1244] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Autosomal dominant progressive external ophthalmoplegia (adPEO) is a mitochondrial disease characterized by accumulation of multiple large deletions of mtDNA in patients' tissues. We previously showed that the disease is genetically heterogeneous by assigning two nuclear loci predisposing to mtDNA deletions: one on chromosome 10q 23.3-24.3 in a Finnish family and one on 3p 14.1-21.2 in three Italian families. To reveal any locus-specific disease features, we report here the clinical, biochemical, and molecular genetic characteristics of the 10q-linked disease in the single family reported to date. All seven patients and four asymptomatic subjects had ragged-red fibers and multiple deletions of mtDNA in their muscle. Ptosis and external ophthalmoplegia were the major clinical findings, and depression or avoidant personality traits were frequently, but not consistently, present in the subjects carrying mutant mtDNA. In six of the subjects with mutant mtDNA, the activities of the respiratory chain complexes I or IV, or both, were below or within the low normal range. Two autopsy studies revealed the characteristic distribution of mutant mtDNA in these patients: highest proportion of mutant mtDNA is found in different parts of the brain, followed by the skeletal and ocular muscle, and the heart.
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Affiliation(s)
- A Suomalainen
- Department of Human Molecular Genetics, National Public Health Institute, Helsinki, Finland
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Nikali K, Isosomppi J, Lönnqvist T, Mao JI, Suomalainen A, Peltonen L. Toward cloning of a novel ataxia gene: refined assignment and physical map of the IOSCA locus (SCA8) on 10q24. Genomics 1997; 39:185-91. [PMID: 9027505 DOI: 10.1006/geno.1996.4465] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Infantile onset spinocerebellar ataxia (IOSCA) is a progressive neurological disorder of unknown etiology. It is inherited as an autosomal recessive trait and has so far been reported in just 19 Finnish patients in 13 separate families. We have previously assigned the IOSCA locus (HGMW-approved symbol SCA8) to chromosome 10q, where no previously identified ataxia loci are located. Haplotype analysis combined with genealogical data provided evidence that all the IOSCA cases in Finland originate from a single 30- to 40-generation-old founder mutation. By analyzing extended disease haplotypes observed today, the IOSCA locus can now be restricted to a region between two adjacent microsatellites, D10S192 and D10S1265, with no genetic intermarker distance. We have constructed a detailed physical map of this 270-kb IOSCA region and cytogenetically localized it to 10q24. We have also assigned two previously known genes, PAX2 and CYP17, more precisely into this region, but the sequence analysis of coding regions of these two genes has not revealed mutations in an IOSCA patient. The obtained long-range clones will form the basis for the isolation of a novel ataxia gene.
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Affiliation(s)
- K Nikali
- Department of Human Molecular Genetics, National Public Health Institute, Helsinki, Finland.
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50
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Varilo T, Nikali K, Suomalainen A, Lönnqvist T, Peltonen L. Tracing an ancestral mutation: genealogical and haplotype analysis of the infantile onset spinocerebellar ataxia locus. Genome Res 1996; 6:870-5. [PMID: 8889554 DOI: 10.1101/gr.6.9.870] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Infantile onset spinocerebellar ataxia (IOSCA) is a progressive neurological syndrome exhibiting an autosomal recessive pattern of inheritance. The characteristic features were described in Finland in the beginning of 1990s. Having shown that IOSCA does not segregate with any of the markers linked to other hereditary ataxias and thus represents a genetically distinct disease, we assigned the locus of this new hereditary ataxia to 10q23.3-q24.1. To approximate the age of the Finnish IOSCA mutation and to investigate the possible existence of more than one mutation underlying the disease, the ancestors of 13 IOSCA families were identified by use of church records dating back to the 1500s. The IOSCA pedigrees were frequently merged, providing support for these having one common ancestor. Analysis of the extended IOSCA haplotypes exposed ancient recombination events and revealed one core haplotype of four markers on a region of approximately 2 cM, which was unequivocally present in 92% of disease chromosomes. Both genealogical and haplotype data thus suggest that a single IOSCA ancestral mutation was introduced into the Finnish population most probably approximately 30-40 generations ago before the time when the general east-west migration took place within Finland.
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Affiliation(s)
- T Varilo
- Department of Human Molecular Genetics, National Public Health Institute, Helsinki, Finland
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