1
|
Vinciguerra C, Iacono S, Bevilacqua L, Landolfi A, Piscosquito G, Ginanneschi F, Schirò G, Di Stefano V, Brighina F, Barone P, Balistreri CR. Sex differences in neuromuscular disorders. Mech Ageing Dev 2023; 211:111793. [PMID: 36806604 DOI: 10.1016/j.mad.2023.111793] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/13/2023] [Accepted: 02/16/2023] [Indexed: 02/19/2023]
Abstract
The prevalence, onset, pathophysiology, and clinical course of many neuromuscular disorders (NMDs) may significantly differ between males and females. Some NMDs are more frequently observed in females, and characterized to show a higher grade of severity during or after the pregnancy. Meanwhile, others tend to have an earlier onset in males and exhibit a more variable progression. Prevalently, sex differences in NMDs have a familiar character given from genetic inheritance. However, they may also influence clinical presentation and disease severity of acquired NMD forms, and are represented by both hormonal and genetic factors. Consequently, to shed light on the distinctive role of biological factors in the different clinical phenotypes, we summarize in this review the sex related differences and their distinctive biological roles emerging from the current literature in both acquired and inherited NMDs.
Collapse
Affiliation(s)
- Claudia Vinciguerra
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy.
| | - Salvatore Iacono
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Liliana Bevilacqua
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Annamaria Landolfi
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Giuseppe Piscosquito
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Federica Ginanneschi
- Department of Medical, Surgical and Neurological Sciences, University of Siena, 53100 Siena, Italy
| | - Giuseppe Schirò
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Vincenzo Di Stefano
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Filippo Brighina
- Neurology Unit, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Paolo Barone
- Neurology Unit, Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, 84131 Salerno, Italy
| | - Carmela Rita Balistreri
- Cellular and Molecular Laboratory, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, 90134 Palermo
| |
Collapse
|
2
|
Morales F, Corrales E, Vásquez M, Zhang B, Fernández H, Alvarado F, Cortés S, Santamaría-Ulloa C, Initiative-Mmdbdi MMDBD, Krahe R, Monckton DG. Individual-specific levels of CTG•CAG somatic instability are shared across multiple tissues in myotonic dystrophy type 1. Hum Mol Genet 2023; 32:621-631. [PMID: 36099027 DOI: 10.1093/hmg/ddac231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/16/2022] [Accepted: 09/09/2022] [Indexed: 02/07/2023] Open
Abstract
Myotonic dystrophy type 1 is a complex disease caused by a genetically unstable CTG repeat expansion in the 3'-untranslated region of the DMPK gene. Age-dependent, tissue-specific somatic instability has confounded genotype-phenotype associations, but growing evidence suggests that it also contributes directly toward disease progression. Using a well-characterized clinical cohort of DM1 patients from Costa Rica, we quantified somatic instability in blood, buccal cells, skin and skeletal muscle. Whilst skeletal muscle showed the largest expansions, modal allele lengths in skin were also very large and frequently exceeded 2000 CTG repeats. Similarly, the degree of somatic expansion in blood, muscle and skin were associated with each other. Notably, we found that the degree of somatic expansion in skin was highly predictive of that in skeletal muscle. More importantly, we established that individuals whose repeat expanded more rapidly than expected in one tissue (after correction for progenitor allele length and age) also expanded more rapidly than expected in other tissues. We also provide evidence suggesting that individuals in whom the repeat expanded more rapidly than expected in skeletal muscle have an earlier age at onset than expected (after correction for the progenitor allele length). Pyrosequencing analyses of the genomic DNA flanking the CTG repeat revealed that the degree of methylation in muscle was well predicted by the muscle modal allele length and age, but that neither methylation of the flanking DNA nor levels of DMPK sense and anti-sense transcripts could obviously explain individual- or tissue-specific patterns of somatic instability.
Collapse
Affiliation(s)
- Fernando Morales
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José 2060, Costa Rica
| | - Eyleen Corrales
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José 2060, Costa Rica
| | - Melissa Vásquez
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José 2060, Costa Rica
| | - Baili Zhang
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030-4009, USA
| | - Huberth Fernández
- Hospital Calderón Guardia/Escuela de Medicina, Universidad de Costa Rica, San José 2060, Costa Rica
| | - Fernando Alvarado
- Hospital Calderón Guardia/Escuela de Medicina, Universidad de Costa Rica, San José 2060, Costa Rica
| | - Sergio Cortés
- Hospital Calderón Guardia/Escuela de Medicina, Universidad de Costa Rica, San José 2060, Costa Rica
| | | | | | - Ralf Krahe
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030-4009, USA
| | - Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| |
Collapse
|
3
|
Tieleman AA, Damen MJ, Verrips A, Roelofs M, Kamsteeg EJ, Voermans NC. Child Neurology: Maternal Transmission of Congenital Myotonic Dystrophy Type 2: Case Report. Neurology 2022; 99:1112-1114. [PMID: 36180234 DOI: 10.1212/wnl.0000000000201427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 09/02/2022] [Indexed: 11/15/2022] Open
Abstract
Congenital manifestations in Myotonic Dystrophy type 2 (DM2) point to anticipation and have only rarely been described. We report a three-generation family with genetically confirmed DM2. The youngest family member presented with unilateral congenital pes planovalgus and equinus. Genetic analysis in four family members showed a CCTG repeat expansion in the CNBP gene. We highlight the association between foot deformities and congenital DM2. Remarkably, the transmission to the congenital form of DM2 has been exclusively maternal so far. If this association is confirmed in other families, clinical practice and genetic counseling in DM2 families need to be adapted.
Collapse
Affiliation(s)
- Alide A Tieleman
- From the Department of Neurology (A.A.T., M.J.D., N.C.V.), Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen; Department of Neurology (A.V.), Canisius Wilhelmina Hospital, Nijmegen; Basalt Medical Rehabilitation Center (M.R.), the Hague; and Department of Genetics (E.-J.K.), Radboud University Medical Center, Nijmegen, the Netherlands.
| | - Manon J Damen
- From the Department of Neurology (A.A.T., M.J.D., N.C.V.), Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen; Department of Neurology (A.V.), Canisius Wilhelmina Hospital, Nijmegen; Basalt Medical Rehabilitation Center (M.R.), the Hague; and Department of Genetics (E.-J.K.), Radboud University Medical Center, Nijmegen, the Netherlands
| | - Aad Verrips
- From the Department of Neurology (A.A.T., M.J.D., N.C.V.), Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen; Department of Neurology (A.V.), Canisius Wilhelmina Hospital, Nijmegen; Basalt Medical Rehabilitation Center (M.R.), the Hague; and Department of Genetics (E.-J.K.), Radboud University Medical Center, Nijmegen, the Netherlands
| | - Monique Roelofs
- From the Department of Neurology (A.A.T., M.J.D., N.C.V.), Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen; Department of Neurology (A.V.), Canisius Wilhelmina Hospital, Nijmegen; Basalt Medical Rehabilitation Center (M.R.), the Hague; and Department of Genetics (E.-J.K.), Radboud University Medical Center, Nijmegen, the Netherlands
| | - Erik-Jan Kamsteeg
- From the Department of Neurology (A.A.T., M.J.D., N.C.V.), Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen; Department of Neurology (A.V.), Canisius Wilhelmina Hospital, Nijmegen; Basalt Medical Rehabilitation Center (M.R.), the Hague; and Department of Genetics (E.-J.K.), Radboud University Medical Center, Nijmegen, the Netherlands
| | - Nicol C Voermans
- From the Department of Neurology (A.A.T., M.J.D., N.C.V.), Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen; Department of Neurology (A.V.), Canisius Wilhelmina Hospital, Nijmegen; Basalt Medical Rehabilitation Center (M.R.), the Hague; and Department of Genetics (E.-J.K.), Radboud University Medical Center, Nijmegen, the Netherlands
| |
Collapse
|
4
|
Baud A, Derbis M, Tutak K, Sobczak K. Partners in crime: Proteins implicated in
RNA
repeat expansion diseases. WIRES RNA 2022; 13:e1709. [PMID: 35229468 PMCID: PMC9539487 DOI: 10.1002/wrna.1709] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Anna Baud
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Magdalena Derbis
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Katarzyna Tutak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Krzysztof Sobczak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| |
Collapse
|
5
|
Barbé L, Finkbeiner S. Genetic and Epigenetic Interplay Define Disease Onset and Severity in Repeat Diseases. Front Aging Neurosci 2022; 14:750629. [PMID: 35592702 PMCID: PMC9110800 DOI: 10.3389/fnagi.2022.750629] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
Repeat diseases, such as fragile X syndrome, myotonic dystrophy, Friedreich ataxia, Huntington disease, spinocerebellar ataxias, and some forms of amyotrophic lateral sclerosis, are caused by repetitive DNA sequences that are expanded in affected individuals. The age at which an individual begins to experience symptoms, and the severity of disease, are partially determined by the size of the repeat. However, the epigenetic state of the area in and around the repeat also plays an important role in determining the age of disease onset and the rate of disease progression. Many repeat diseases share a common epigenetic pattern of increased methylation at CpG islands near the repeat region. CpG islands are CG-rich sequences that are tightly regulated by methylation and are often found at gene enhancer or insulator elements in the genome. Methylation of CpG islands can inhibit binding of the transcriptional regulator CTCF, resulting in a closed chromatin state and gene down regulation. The downregulation of these genes leads to some disease-specific symptoms. Additionally, a genetic and epigenetic interplay is suggested by an effect of methylation on repeat instability, a hallmark of large repeat expansions that leads to increasing disease severity in successive generations. In this review, we will discuss the common epigenetic patterns shared across repeat diseases, how the genetics and epigenetics interact, and how this could be involved in disease manifestation. We also discuss the currently available stem cell and mouse models, which frequently do not recapitulate epigenetic patterns observed in human disease, and propose alternative strategies to study the role of epigenetics in repeat diseases.
Collapse
Affiliation(s)
- Lise Barbé
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, CA, United States
- Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
| | - Steve Finkbeiner
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, CA, United States
- Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
- *Correspondence: Steve Finkbeiner,
| |
Collapse
|
6
|
Kong HE, Pollack BP. Cutaneous findings in myotonic dystrophy. JAAD Int 2022; 7:7-12. [PMID: 35243403 PMCID: PMC8867117 DOI: 10.1016/j.jdin.2021.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2021] [Indexed: 11/06/2022] Open
Abstract
Myotonic dystrophy types 1 and 2 are a group of complex genetic disorders resulting from the expansion of (CTG)n nucleotide repeats in the DMPK gene. In addition to the hallmark manifestations of myotonia and skeletal muscle atrophy, myotonic dystrophy also affects a myriad of other organs including the heart, lungs, as well as the skin. The most common cutaneous manifestations of myotonic dystrophy are early male frontal alopecia and adult-onset pilomatricomas. Myotonic dystrophy also increases the risk of developing malignant skin diseases such as basal cell carcinoma and melanoma. To aid in the diagnosis and treatment of myotonic dystrophy related skin conditions, it is important for the dermatologist to become cognizant of the common and rare cutaneous manifestations of this genetic disorder. We performed a PubMed search using the key terms “myotonic dystrophy” AND “cutaneous” OR “skin” OR “dermatologic” AND “manifestation” OR “finding.” The resulting publications were manually reviewed for additional relevant publications, and subsequent additional searches were performed as needed, especially regarding the molecular mechanisms of pathogenesis. In this review, we aim to provide an overview of myotonic dystrophy types 1 and 2 and summarize their cutaneous manifestations as well as potential mechanisms of pathogenesis.
Collapse
Affiliation(s)
- Ha Eun Kong
- Department of Dermatology, Emory University School of Medicine, Atlanta, Georgia
| | - Brian P Pollack
- Atlanta VA Health System, Decatur, Georgia.,Department of Dermatology, Emory University School of Medicine, Atlanta, Georgia.,Department of Pathology, Emory University School of Medicine, Atlanta, Georgia.,Winship Cancer Institute of Emory University School of Medicine, Atlanta, Georgia
| |
Collapse
|
7
|
Gall-Duncan T, Sato N, Yuen RKC, Pearson CE. Advancing genomic technologies and clinical awareness accelerates discovery of disease-associated tandem repeat sequences. Genome Res 2022; 32:1-27. [PMID: 34965938 PMCID: PMC8744678 DOI: 10.1101/gr.269530.120] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 11/29/2021] [Indexed: 11/25/2022]
Abstract
Expansions of gene-specific DNA tandem repeats (TRs), first described in 1991 as a disease-causing mutation in humans, are now known to cause >60 phenotypes, not just disease, and not only in humans. TRs are a common form of genetic variation with biological consequences, observed, so far, in humans, dogs, plants, oysters, and yeast. Repeat diseases show atypical clinical features, genetic anticipation, and multiple and partially penetrant phenotypes among family members. Discovery of disease-causing repeat expansion loci accelerated through technological advances in DNA sequencing and computational analyses. Between 2019 and 2021, 17 new disease-causing TR expansions were reported, totaling 63 TR loci (>69 diseases), with a likelihood of more discoveries, and in more organisms. Recent and historical lessons reveal that properly assessed clinical presentations, coupled with genetic and biological awareness, can guide discovery of disease-causing unstable TRs. We highlight critical but underrecognized aspects of TR mutations. Repeat motifs may not be present in current reference genomes but will be in forthcoming gapless long-read references. Repeat motif size can be a single nucleotide to kilobases/unit. At a given locus, repeat motif sequence purity can vary with consequence. Pathogenic repeats can be "insertions" within nonpathogenic TRs. Expansions, contractions, and somatic length variations of TRs can have clinical/biological consequences. TR instabilities occur in humans and other organisms. TRs can be epigenetically modified and/or chromosomal fragile sites. We discuss the expanding field of disease-associated TR instabilities, highlighting prospects, clinical and genetic clues, tools, and challenges for further discoveries of disease-causing TR instabilities and understanding their biological and pathological impacts-a vista that is about to expand.
Collapse
Affiliation(s)
- Terence Gall-Duncan
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Nozomu Sato
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
| | - Ryan K C Yuen
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Christopher E Pearson
- Program of Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| |
Collapse
|
8
|
Abstract
At fifteen different genomic locations, the expansion of a CAG/CTG repeat causes a neurodegenerative or neuromuscular disease, the most common being Huntington's disease and myotonic dystrophy type 1. These disorders are characterized by germline and somatic instability of the causative CAG/CTG repeat mutations. Repeat lengthening, or expansion, in the germline leads to an earlier age of onset or more severe symptoms in the next generation. In somatic cells, repeat expansion is thought to precipitate the rate of disease. The mechanisms underlying repeat instability are not well understood. Here we review the mammalian model systems that have been used to study CAG/CTG repeat instability, and the modifiers identified in these systems. Mouse models have demonstrated prominent roles for proteins in the mismatch repair pathway as critical drivers of CAG/CTG instability, which is also suggested by recent genome-wide association studies in humans. We draw attention to a network of connections between modifiers identified across several systems that might indicate pathway crosstalk in the context of repeat instability, and which could provide hypotheses for further validation or discovery. Overall, the data indicate that repeat dynamics might be modulated by altering the levels of DNA metabolic proteins, their regulation, their interaction with chromatin, or by direct perturbation of the repeat tract. Applying novel methodologies and technologies to this exciting area of research will be needed to gain deeper mechanistic insight that can be harnessed for therapies aimed at preventing repeat expansion or promoting repeat contraction.
Collapse
Affiliation(s)
- Vanessa C. Wheeler
- Molecular Neurogenetics Unit, Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA,Department of Neurology, Harvard Medical School, Boston, MA, USA,Correspondence to: Vanessa C. Wheeler, Center for Genomic Medicine, Massachusetts Hospital, Boston MAA 02115, USA. E-mail: . and Vincent Dion, UK Dementia Research Institute at Cardiff University, Hadyn Ellis Building, Maindy Road, CF24 4HQ Cardiff, UK. E-mail:
| | - Vincent Dion
- UK Dementia Research Institute at Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, UK,Correspondence to: Vanessa C. Wheeler, Center for Genomic Medicine, Massachusetts Hospital, Boston MAA 02115, USA. E-mail: . and Vincent Dion, UK Dementia Research Institute at Cardiff University, Hadyn Ellis Building, Maindy Road, CF24 4HQ Cardiff, UK. E-mail:
| |
Collapse
|
9
|
Morales F, Vásquez M, Corrales E, Vindas-Smith R, Santamaría-Ulloa C, Zhang B, Sirito M, Estecio MR, Krahe R, Monckton DG. Longitudinal increases in somatic mosaicism of the expanded CTG repeat in myotonic dystrophy type 1 are associated with variation in age-at-onset. Hum Mol Genet 2021; 29:2496-2507. [PMID: 32601694 DOI: 10.1093/hmg/ddaa123] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 04/13/2020] [Accepted: 06/16/2020] [Indexed: 12/26/2022] Open
Abstract
In myotonic dystrophy type 1 (DM1), somatic mosaicism of the (CTG)n repeat expansion is age-dependent, tissue-specific and expansion-biased. These features contribute toward variation in disease severity and confound genotype-to-phenotype analyses. To investigate how the (CTG)n repeat expansion changes over time, we collected three longitudinal blood DNA samples separated by 8-15 years and used small pool and single-molecule PCR in 43 DM1 patients. We used the lower boundary of the allele length distribution as the best estimate for the inherited progenitor allele length (ePAL), which is itself the best predictor of disease severity. Although in most patients the lower boundary of the allele length distribution was conserved over time, in many this estimate also increased with age, suggesting samples for research studies and clinical trials should be obtained as early as possible. As expected, the modal allele length increased over time, driven primarily by ePAL, age-at-sampling and the time interval. As expected, small expansions <100 repeats did not expand as rapidly as larger alleles. However, the rate of expansion of very large alleles was not obviously proportionally higher. This may, at least in part, be a result of the allele length-dependent increase in large contractions that we also observed. We also determined that individual-specific variation in the increase of modal allele length over time not accounted for by ePAL, age-at-sampling and time was inversely associated with individual-specific variation in age-at-onset not accounted for by ePAL, further highlighting somatic expansion as a therapeutic target in DM1.
Collapse
Affiliation(s)
- Fernando Morales
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, Costa Rica
| | - Melissa Vásquez
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, Costa Rica
| | - Eyleen Corrales
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, Costa Rica
| | - Rebeca Vindas-Smith
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, Costa Rica
| | | | - Baili Zhang
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Mario Sirito
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Marcos R Estecio
- Department of Epigenetics & Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ralf Krahe
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| |
Collapse
|
10
|
Morales F, Corrales E, Zhang B, Vásquez M, Santamaría-Ulloa C, Quesada H, Sirito M, Estecio MR, Monckton DG, Krahe R. Myotonic dystrophy type 1 (DM1) clinical sub-types and CTCF site methylation status flanking the CTG expansion are mutant allele length-dependent. Hum Mol Genet 2021; 31:262-274. [PMID: 34432028 DOI: 10.1093/hmg/ddab243] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/15/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a complex disease with a wide spectrum of symptoms. The exact relationship between mutant CTG repeat expansion size and clinical outcome remains unclear. DM1 congenital patients (CDM) inherit the largest expanded alleles, which are associated with abnormal and increased DNA methylation flanking the CTG repeat. However, DNA methylation at the DMPK locus remains understudied. Its relationship to DM1 clinical subtypes, expansion size and age-at-onset is not yet completely understood. Using pyrosequencing-based methylation analysis on 225 blood DNA samples from Costa Rican DM1 patients, we determined that the size of the estimated progenitor allele length (ePAL) is not only a good discriminator between CDM and non-CDM cases (with an estimated threshold at 653 CTG repeats), but also for all DM1 clinical subtypes. Secondly, increased methylation at both CTCF sites upstream and downstream of the expansion was almost exclusively present in CDM cases. Thirdly, levels of abnormal methylation were associated with clinical subtype, age and ePAL, with strong correlations between these variables. Fourthly, both ePAL and the intergenerational expansion size were significantly associated with methylation status. Finally, methylation status was associated with ePAL and maternal inheritance, with almost exclusively maternal transmission of CDM. In conclusion, increased DNA methylation at the CTCF sites flanking the DM1 expansion could be linked to ePAL, and both increased methylation and the ePAL could be considered biomarkers for the CDM phenotype.
Collapse
Affiliation(s)
- Fernando Morales
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, 2060, Costa Rica
| | - Eyleen Corrales
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, 2060, Costa Rica
| | - Baili Zhang
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA
| | - Melissa Vásquez
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, 2060, Costa Rica
| | - Carolina Santamaría-Ulloa
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, 2060, Costa Rica
| | - Hazel Quesada
- Instituto de Investigaciones en Salud (INISA), Universidad de Costa Rica, San José, 2060, Costa Rica
| | - Mario Sirito
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA
| | - Marcos R Estecio
- Department of Epigenetics & Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA.,Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA
| | - Darren G Monckton
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Ralf Krahe
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA.,Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Houston, Texas, 77030-4009, USA
| |
Collapse
|
11
|
Abstract
OBJECTIVE This study explored mental rotation (MR) performance in patients with myotonic dystrophy 1 (DM1), an inherited neuromuscular disorder dominated by muscular symptoms, including muscle weakness and myotonia. The aim of the study was twofold: to gain new insights into the neurocognitive mechanisms of MR and to better clarify the cognitive profile of DM1 patients. To address these aims, we used MR tasks involving kinds of stimuli that varied for the extent to which they emphasized motor simulation and activation of body representations (body parts) versus visuospatial imagery (abstract objects). We hypothesized that, if peripheral sensorimotor feedback system plays a pivotal role in modulating MR performance, then DM1 patients would exhibit more difficulties in mentally rotating hand stimuli than abstract objects. METHOD Twenty-four DM1 patients and twenty-four age- and education-matched control subjects were enrolled in the study and were required to perform two computerized MR tasks involving pictures of hands and abstract objects. RESULTS The analysis of accuracy showed that patients had impaired MR performance when the angular disparities between the stimuli were higher. Notably, as compared to controls, patients showed slower responses when the stimuli were hands, whereas no significant differences when stimuli were objects. CONCLUSION The findings are coherent with the embodied cognition view, indicating a tight relation between body- and motor-related processes and MR. They suggest that peripheral, muscular, abnormalities in DM1 lead to alterations in manipulation of motor representations, which in turn affect MR, especially when body parts are to mentally rotate.
Collapse
|
12
|
Joosten IBT, Hellebrekers DMEI, de Greef BTA, Smeets HJM, de Die-Smulders CEM, Faber CG, Gerrits MM. Parental repeat length instability in myotonic dystrophy type 1 pre- and protomutations. Eur J Hum Genet 2020; 28:956-962. [PMID: 32203199 DOI: 10.1038/s41431-020-0601-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 02/14/2020] [Accepted: 02/25/2020] [Indexed: 01/03/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1) is caused by a CTG trinucleotide repeat expansion on chromosome 19q13.3. While DM1 premutation (36-50 repeats) and protomutation (51-80 repeats) allele carriers are mostly asymptomatic, offspring is at risk of inheriting expanded, symptom-associated, (CTG)n repeats of n > 80. In this study we aimed to evaluate the intergenerational instability of DM1 pre- and protomutation alleles, focussing on the influence of parental gender. One hundred and forty-six parent-child pairs (34 parental premutations, 112 protomutations) were retrospectively selected from the DM1 patient cohort of the Maastricht University Medical Center+. CTG repeat size of parents and children was determined by (triplet-primed) PCR followed by fragment length analysis and Southern blot analysis. Fifty-eight out of eighty-one (71.6%) paternal transmissions led to a (CTG)n repeat of n > 80 in offspring, compared with 15 out of 65 (23.1%) maternal transmissions (p < 0.001). Repeat length instability occurred for paternal (CTG)n repeats of n ≥ 45, while maternal instability did not occur until (CTG)n repeats reached a length of n ≥ 71. Transmission of premutations caused (CTG)n repeats of n > 80 in offspring only when paternally transmitted (two cases), while protomutations caused (CTG)n repeats of n > 80 in offspring in 71 cases, of which 56 (78.9%) were paternally transmitted. In conclusion, our data show that paternally transmitted pre- and protomutations were more unstable than maternally transmitted pre- and protomutations. For genetic counseling, this implies that males with a small DMPK mutation have a higher risk of symptomatic offspring compared with females. Consequently, we suggest addressing sex-dependent factors in genetic counseling of small-sized CTG repeat carriers.
Collapse
Affiliation(s)
- Isis B T Joosten
- Department of Neurology, Maastricht University Medical Center+, Maastricht, The Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Debby M E I Hellebrekers
- Department of Clinical Genetics, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Bianca T A de Greef
- Department of Neurology, Maastricht University Medical Center+, Maastricht, The Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Clinical Epidemiology and Medical Technology Assessment, Maastricht University Medical Center+, Maastricht, The Netherlands
| | - Hubert J M Smeets
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands.,Department of Genetics and Cell Biology, Clinical Genomics Unit, Maastricht University, Maastricht, The Netherlands.,School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
| | | | - Catharina G Faber
- Department of Neurology, Maastricht University Medical Center+, Maastricht, The Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Monique M Gerrits
- Department of Clinical Genetics, Maastricht University Medical Center+, Maastricht, The Netherlands.
| |
Collapse
|
13
|
Cumming SA, Jimenez-Moreno C, Okkersen K, Wenninger S, Daidj F, Hogarth F, Littleford R, Gorman G, Bassez G, Schoser B, Lochmüller H, van Engelen BGM, Monckton DG. Genetic determinants of disease severity in the myotonic dystrophy type 1 OPTIMISTIC cohort. Neurology 2019; 93:e995-e1009. [PMID: 31395669 PMCID: PMC6745735 DOI: 10.1212/wnl.0000000000008056] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 04/10/2019] [Indexed: 01/11/2023] Open
Abstract
Objective To evaluate the role of genetic variation at the DMPK locus on symptomatic diversity in 250 adult, ambulant patients with myotonic dystrophy type 1 (DM1) recruited to the Observational Prolonged Trial in Myotonic Dystrophy Type 1 to Improve Quality of Life—Standards, a Target Identification Collaboration (OPTIMISTIC) clinical trial. Methods We used small pool PCR to correct age at sampling biases and estimate the progenitor allele CTG repeat length and somatic mutational dynamics, and AciI digests and repeat primed PCR to test for the presence of variant repeats. Results We confirmed disease severity is driven by progenitor allele length, is further modified by age, and, in some cases, sex, and that patients in whom the CTG repeat expands more rapidly in the soma develop symptoms earlier than predicted. We revealed a key role for variant repeats in reducing disease severity and quantified their role in delaying age at onset by approximately 13.2 years (95% confidence interval 5.7–20.7, 2-tailed t test t = −3.7, p = 0.0019). Conclusions Careful characterization of the DMPK CTG repeat to define progenitor allele length and presence of variant repeats has increased utility in understanding clinical variability in a trial cohort and provides a genetic route for defining disease-specific outcome measures, and the basis of treatment response and stratification in DM1 trials.
Collapse
Affiliation(s)
- Sarah A Cumming
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Cecilia Jimenez-Moreno
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Kees Okkersen
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Stephan Wenninger
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Ferroudja Daidj
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Fiona Hogarth
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Roberta Littleford
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Gráinne Gorman
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Guillaume Bassez
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Benedikt Schoser
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Hanns Lochmüller
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Baziel G M van Engelen
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK
| | - Darren G Monckton
- From the Institute of Molecular, Cell and Systems Biology (S.A.C., D.G.M.), University of Glasgow; Institute of Genetic Medicine (C.J.-M., H.L.) and Institute of Neurosciences (G.G.), Newcastle University, Newcastle upon Tyne, UK; Department of Neurology (K.O., B.G.M.v.E.), Donders Institute for Brain Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (S.W., B.S.), Friedrich-Baur-Institute, Ludwig-Maximilians-Universität München, Munich, Germany; Neuromuscular Reference Centre (F.D., G.B.), Assistance Publique-Hôpitaux de Paris, France; and Tayside Clinical Trials Unit (F.H., R.L.), The University of Dundee, UK.
| | | |
Collapse
|
14
|
Analysis of mutational dynamics at the DMPK (CTG)n locus identifies saliva as a suitable DNA sample source for genetic analysis in myotonic dystrophy type 1. PLoS One 2019; 14:e0216407. [PMID: 31048891 PMCID: PMC6497304 DOI: 10.1371/journal.pone.0216407] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 04/21/2019] [Indexed: 12/12/2022] Open
Abstract
Genotype-to-phenotype correlation studies in myotonic dystrophy type 1 (DM1) have been confounded by the age-dependent, tissue-specific and expansion-biased features of somatic mosaicism of the expanded CTG repeat. Previously, we showed that by controlling for the confounding effects of somatic instability to estimate the progenitor allele CTG length in blood DNA, age at onset correlations could be significantly improved. To determine the suitability of saliva DNA as a source for genotyping, we used small pool-PCR to perform a detailed quantitative study of the somatic mutational dynamics of the CTG repeat in saliva and blood DNA from 40 DM1 patients. Notably, the modal allele length in saliva was only moderately higher in saliva and not as large as previously observed in most other tissues. The lower boundary of the allele distribution was also slightly higher in saliva than it was in blood DNA. However, the progenitor allele length estimated in blood explained more of the variation in age at onset than that estimated from saliva. Interestingly, although the modal allele length was slightly higher in saliva, the overall degree of somatic variation was typically lower than in blood DNA, revealing new insights into the tissue-specific dynamics of somatic mosaicism. These data indicate that saliva constitutes an accessible, non-invasive and suitable DNA sample source for performing genetic studies in DM1.
Collapse
|
15
|
Abstract
Repeat expansions in the promoter region of C9orf72 are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and related disorders of the ALS/frontotemporal lobar degeneration (FTLD) spectrum. Remarkable clinical heterogeneity among patients with a repeat expansion has been observed, and genetic anticipation over different generations has been suggested. Genetic factors modifying the clinical phenotype have been proposed, including genetic variation in other known disease genes, the genomic context of the C9orf72 repeat, and expanded repeat size, which has been estimated between 45 and several thousand units. The role of variability in normal and expanded repeat sizes for disease risk and clinical phenotype is under debate. Different pathogenic mechanisms have been proposed, including loss of function, RNA toxicity, and dipeptide repeat (DPR) protein toxicity resulting from abnormal translation of the expanded repeat, but the major mechanism is yet unclear.
Collapse
|
16
|
Abstract
More than 40 diseases, most of which primarily affect the nervous system, are caused by expansions of simple sequence repeats dispersed throughout the human genome. Expanded trinucleotide repeat diseases were discovered first and remain the most frequent. More recently tetra-, penta-, hexa-, and even dodeca-nucleotide repeat expansions have been identified as the cause of human disease, including some of the most common genetic disorders seen by neurologists. Repeat expansion diseases include both causes of myotonic dystrophy (DM1 and DM2), the most common genetic cause of amyotrophic lateral sclerosis/frontotemporal dementia (C9ORF72), Huntington disease, and eight other polyglutamine disorders, including the most common forms of dominantly inherited ataxia, the most common recessive ataxia (Friedreich ataxia), and the most common heritable mental retardation (fragile X syndrome). Here I review distinctive features of this group of diseases that stem from the unusual, dynamic nature of the underlying mutations. These features include marked clinical heterogeneity and the phenomenon of clinical anticipation. I then discuss the diverse molecular mechanisms driving disease pathogenesis, which vary depending on the repeat sequence, size, and location within the disease gene, and whether the repeat is translated into protein. I conclude with a brief clinical and genetic description of individual repeat expansion diseases that are most relevant to neurologists.
Collapse
|
17
|
Barbé L, Lanni S, López-Castel A, Franck S, Spits C, Keymolen K, Seneca S, Tomé S, Miron I, Letourneau J, Liang M, Choufani S, Weksberg R, Wilson MD, Sedlacek Z, Gagnon C, Musova Z, Chitayat D, Shannon P, Mathieu J, Sermon K, Pearson CE. CpG Methylation, a Parent-of-Origin Effect for Maternal-Biased Transmission of Congenital Myotonic Dystrophy. Am J Hum Genet 2017; 100:488-505. [PMID: 28257691 PMCID: PMC5339342 DOI: 10.1016/j.ajhg.2017.01.033] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/26/2017] [Indexed: 12/13/2022] Open
Abstract
CTG repeat expansions in DMPK cause myotonic dystrophy (DM1) with a continuum of severity and ages of onset. Congenital DM1 (CDM1), the most severe form, presents distinct clinical features, large expansions, and almost exclusive maternal transmission. The correlation between CDM1 and expansion size is not absolute, suggesting contributions of other factors. We determined CpG methylation flanking the CTG repeat in 79 blood samples from 20 CDM1-affected individuals; 21, 27, and 11 individuals with DM1 but not CDM1 (henceforth non-CDM1) with maternal, paternal, and unknown inheritance; and collections of maternally and paternally derived chorionic villus samples (7 CVSs) and human embryonic stem cells (4 hESCs). All but two CDM1-affected individuals showed high levels of methylation upstream and downstream of the repeat, greater than non-CDM1 individuals (p = 7.04958 × 10−12). Most non-CDM1 individuals were devoid of methylation, where one in six showed downstream methylation. Only two non-CDM1 individuals showed upstream methylation, and these were maternally derived childhood onset, suggesting a continuum of methylation with age of onset. Only maternally derived hESCs and CVSs showed upstream methylation. In contrast, paternally derived samples (27 blood samples, 3 CVSs, and 2 hESCs) never showed upstream methylation. CTG tract length did not strictly correlate with CDM1 or methylation. Thus, methylation patterns flanking the CTG repeat are stronger indicators of CDM1 than repeat size. Spermatogonia with upstream methylation may not survive due to methylation-induced reduced expression of the adjacent SIX5, thereby protecting DM1-affected fathers from having CDM1-affected children. Thus, DMPK methylation may account for the maternal bias for CDM1 transmission, larger maternal CTG expansions, age of onset, and clinical continuum, and may serve as a diagnostic indicator.
Collapse
|
18
|
Dogan C, De Antonio M, Hamroun D, Varet H, Fabbro M, Rougier F, Amarof K, Arne Bes MC, Bedat-Millet AL, Behin A, Bellance R, Bouhour F, Boutte C, Boyer F, Campana-Salort E, Chapon F, Cintas P, Desnuelle C, Deschamps R, Drouin-Garraud V, Ferrer X, Gervais-Bernard H, Ghorab K, Laforet P, Magot A, Magy L, Menard D, Minot MC, Nadaj-Pakleza A, Pellieux S, Pereon Y, Preudhomme M, Pouget J, Sacconi S, Sole G, Stojkovich T, Tiffreau V, Urtizberea A, Vial C, Zagnoli F, Caranhac G, Bourlier C, Riviere G, Geille A, Gherardi RK, Eymard B, Puymirat J, Katsahian S, Bassez G. Gender as a Modifying Factor Influencing Myotonic Dystrophy Type 1 Phenotype Severity and Mortality: A Nationwide Multiple Databases Cross-Sectional Observational Study. PLoS One 2016; 11:e0148264. [PMID: 26849574 PMCID: PMC4744025 DOI: 10.1371/journal.pone.0148264] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 01/16/2016] [Indexed: 01/06/2023] Open
Abstract
Background Myotonic Dystrophy type 1 (DM1) is one of the most heterogeneous hereditary disease in terms of age of onset, clinical manifestations, and severity, challenging both medical management and clinical trials. The CTG expansion size is the main factor determining the age of onset although no factor can finely predict phenotype and prognosis. Differences between males and females have not been specifically reported. Our aim is to study gender impact on DM1 phenotype and severity. Methods We first performed cross-sectional analysis of main multiorgan clinical parameters in 1409 adult DM1 patients (>18y) from the DM-Scope nationwide registry and observed different patterns in males and females. Then, we assessed gender impact on social and economic domains using the AFM-Téléthon DM1 survey (n = 970), and morbidity and mortality using the French National Health Service Database (n = 3301). Results Men more frequently had (1) severe muscular disability with marked myotonia, muscle weakness, cardiac, and respiratory involvement; (2) developmental abnormalities with facial dysmorphism and cognitive impairment inferred from low educational levels and work in specialized environments; and (3) lonely life. Alternatively, women more frequently had cataracts, dysphagia, digestive tract dysfunction, incontinence, thyroid disorder and obesity. Most differences were out of proportion to those observed in the general population. Compared to women, males were more affected in their social and economic life. In addition, they were more frequently hospitalized for cardiac problems, and had a higher mortality rate. Conclusion Gender is a previously unrecognized factor influencing DM1 clinical profile and severity of the disease, with worse socio-economic consequences of the disease and higher morbidity and mortality in males. Gender should be considered in the design of both stratified medical management and clinical trials.
Collapse
Affiliation(s)
- Celine Dogan
- Neuromuscular Reference Center, GH Henri Mondor, AP-HP, Créteil, France, INSERM U955, UPEC university, Créteil, France
| | - Marie De Antonio
- Neuromuscular Reference Center, GH Henri Mondor, AP-HP, Créteil, France, INSERM U955, UPEC university, Créteil, France
- INSERM U1138, Centre de recherche des cordeliers, Paris Descartes university, UPMC university, Paris, France
| | - Dalil Hamroun
- Direction de la Recherche et de l'Innovation, CHU Montpellier, Montpellier, France
| | - Hugo Varet
- Neuromuscular Reference Center, GH Henri Mondor, AP-HP, Créteil, France, INSERM U955, UPEC university, Créteil, France
| | - Marianne Fabbro
- Neuromuscular Reference Center, GH Henri Mondor, AP-HP, Créteil, France, INSERM U955, UPEC university, Créteil, France
| | - Felix Rougier
- Neuromuscular Reference Center, GH Henri Mondor, AP-HP, Créteil, France, INSERM U955, UPEC university, Créteil, France
| | - Khadija Amarof
- Neuromuscular Reference Center, CHU Fort-de-France, Fort de France, France
| | | | | | - Anthony Behin
- Neuromuscular Reference Center, GH Pitié-Salpêtrière, AP-HP, Paris, France
| | - Remi Bellance
- Neuromuscular Reference Center, CHU Fort-de-France, Fort de France, France
| | | | - Celia Boutte
- Neuromuscular Reference Center, CHU Grenoble, Grenoble, France
| | - François Boyer
- Neuromuscular Reference Center, CHU Reims, Reims, France
| | | | | | - Pascal Cintas
- Neuromuscular Reference Center, CHU Toulouse, Toulouse, France
| | | | - Romain Deschamps
- Neuromuscular Reference Center, CHU Fort-de-France, Fort de France, France
| | | | - Xavier Ferrer
- Neuromuscular Reference Center, CHU Bordeaux, Bordeaux, France
| | | | - Karima Ghorab
- Neuromuscular Reference Center, CHU Limoges, Limoges, France
| | - Pascal Laforet
- Neuromuscular Reference Center, GH Pitié-Salpêtrière, AP-HP, Paris, France
| | - Armelle Magot
- Neuromuscular Reference Center, CHU Nantes, Nantes, France
| | - Laurent Magy
- Neuromuscular Reference Center, CHU Limoges, Limoges, France
| | | | | | | | | | - Yann Pereon
- Neuromuscular Reference Center, CHU Nantes, Nantes, France
| | | | - Jean Pouget
- Neuromuscular Reference Center, GH Timone, AP-HM, Marseille, France
| | | | - Guilhem Sole
- Neuromuscular Reference Center, CHU Bordeaux, Bordeaux, France
| | - Tanya Stojkovich
- Neuromuscular Reference Center, GH Pitié-Salpêtrière, AP-HP, Paris, France
| | | | - Andoni Urtizberea
- Neuromuscular Reference Center, Hôpital Marin, AP-HP, Hendaye, France
| | | | - Fabien Zagnoli
- Neuromuscular Competence Center, HIA Clermont-Tonnerre, Brest, France
| | | | | | | | - Alain Geille
- CoPil, DM1 patients group, AFM-Téléthon, Evry, France
| | - Romain K. Gherardi
- Neuromuscular Reference Center, GH Henri Mondor, AP-HP, Créteil, France, INSERM U955, UPEC university, Créteil, France
| | - Bruno Eymard
- Neuromuscular Reference Center, GH Pitié-Salpêtrière, AP-HP, Paris, France
| | - Jack Puymirat
- Human Genetic Research Unit, CHU Laval, Quebec, Canada
| | - Sandrine Katsahian
- INSERM U1138, Centre de recherche des cordeliers, Paris Descartes university, UPMC university, Paris, France
| | - Guillaume Bassez
- Neuromuscular Reference Center, GH Henri Mondor, AP-HP, Créteil, France, INSERM U955, UPEC university, Créteil, France
- * E-mail:
| |
Collapse
|
19
|
Koutsoulidou A, Kyriakides TC, Papadimas GK, Christou Y, Kararizou E, Papanicolaou EZ, Phylactou LA. Elevated Muscle-Specific miRNAs in Serum of Myotonic Dystrophy Patients Relate to Muscle Disease Progress. PLoS One 2015; 10:e0125341. [PMID: 25915631 PMCID: PMC4411125 DOI: 10.1371/journal.pone.0125341] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/13/2015] [Indexed: 01/24/2023] Open
Abstract
The discovery of reliable and sensitive blood biomarkers is useful for the diagnosis, monitoring and potential future therapy of diseases. Recently, microRNAs (miRNAs) have been identified in blood circulation and might have the potential to be used as biomarkers for several diseases and clinical conditions. Myotonic Dystrophy type 1 (DM1) is the most common form of adult-onset muscular dystrophy primarily characterized by muscle myotonia, weakness and atrophy. Previous studies have shown an association between miRNAs and DM1 in muscle tissue and, recently, in plasma. The aim of this study was to detect and assess muscle-specific miRNAs as potential biomarkers of DM1 muscle wasting, an important parameter in the disease’s natural history. Disease stable or progressive DM1 patients with muscle weakness and wasting were recruited and enrolled in the study. RNA isolated from participants’ serum was used to assess miRNA levels. Results suggest that the levels of muscle-specific miRNAs are correlated with the progression of muscle wasting and weakness observed in the DM1 patients. Specifically, miR-1, miR-133a, miR133b and miR-206 serum levels were found elevated in DM1 patients with progressive muscle wasting compared to disease stable DM1 patients. Based on these results, we propose that muscle-specific miRNAs might be useful molecular biomarkers for monitoring the progress of muscle atrophy in DM1 patients.
Collapse
Affiliation(s)
- Andrie Koutsoulidou
- Department of Molecular Genetics, Function & Therapy, Cyprus Institute of Neurology & Genetics, P.O. Box 2346, 1683 Nicosia, Cyprus
| | - Tassos C. Kyriakides
- Yale Center for Analytical Sciences,Yale School of Public Health, 300 George Street, Suite 555, New Haven, CT 06520, United States of America
| | - George K. Papadimas
- Department of Neurology, Eginitio hospital, Medical School of Athens, 74 Vasilissis Sofias, 11528, Athens, Greece
| | - Yiolanda Christou
- Neurology Clinic D, Cyprus Institute of Neurology & Genetics, P.O. Box 2346, 1683 Nicosia, Cyprus
| | - Evangelia Kararizou
- Department of Neurology, Eginitio hospital, Medical School of Athens, 74 Vasilissis Sofias, 11528, Athens, Greece
| | - Eleni Zamba Papanicolaou
- Neurology Clinic D, Cyprus Institute of Neurology & Genetics, P.O. Box 2346, 1683 Nicosia, Cyprus
| | - Leonidas A. Phylactou
- Department of Molecular Genetics, Function & Therapy, Cyprus Institute of Neurology & Genetics, P.O. Box 2346, 1683 Nicosia, Cyprus
- * E-mail:
| |
Collapse
|
20
|
Efficient and Highly Sensitive Screen for Myotonic Dystrophy Type 1 Using a One-Step Triplet-Primed PCR and Melting Curve Assay. J Mol Diagn 2015; 17:128-35. [DOI: 10.1016/j.jmoldx.2014.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 10/15/2014] [Accepted: 10/22/2014] [Indexed: 01/22/2023] Open
|
21
|
Parental age effects, but no evidence for an intrauterine effect in the transmission of myotonic dystrophy type 1. Eur J Hum Genet 2014; 23:646-53. [PMID: 25052313 DOI: 10.1038/ejhg.2014.138] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 06/02/2014] [Accepted: 06/18/2014] [Indexed: 12/27/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is caused by the expansion of an unstable CTG repeat (g.17294_17296(45_1000)) with more repeats associated with increased disease severity and reduced age at onset. Expanded disease-associated alleles are highly unstable in both the germline and soma. Germline instability is expansion biased, providing a molecular explanation for anticipation. Somatic instability is expansion biased, size- and age-dependent, features that have compromised genotype-phenotype correlations and intergenerational studies. We corrected these confounding factors by estimating the progenitor allele length in 54 father-offspring and 52 mother-offspring pairs in Costa Rican DM1 families. Not surprisingly, we found major parental allele length effects on the size of the allele transmitted, the magnitude of the intergenerational length change, the age at onset in the next generation and the degree of anticipation in both male and female transmissions. We also detected, for the first time, an age-of-parent effect for both male and female transmission. Interestingly, we found no evidence for an intrauterine effect in the transmission of congenital DM1, suggesting previous reports may have been an artefact of age-dependent somatic instability and sampling bias. These data provide new insights into the germline dynamics of the CTG repeat and opportunities for providing additional advice and more accurate risk assessments to prospective parents in DM1 families.
Collapse
|
22
|
Higham CF, Monckton DG. Modelling and inference reveal nonlinear length-dependent suppression of somatic instability for small disease associated alleles in myotonic dystrophy type 1 and Huntington disease. J R Soc Interface 2013; 10:20130605. [PMID: 24047873 DOI: 10.1098/rsif.2013.0605] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
More than 20 human genetic diseases are associated with inheriting an unstable expanded DNA simple sequence tandem repeat, for example, CTG (cytosine-thymine-guanine) repeats in myotonic dystrophy type 1 (DM1) and CAG (cytosine-adenine-guanine) repeats in Huntington disease (HD). These sequences mutate by changing the number of repeats not just between generations, but also during the lifetime of affected individuals. Levels of somatic instability contribute to disease onset and progression but as changes are tissue-specific, age- and repeat length-dependent, interpretation of the level of somatic instability in an individual is confounded by these considerations. Mathematical models, fitted to CTG repeat length distributions derived from blood DNA, from a large cohort of DM1-affected or at risk individuals, have recently been used to quantify inherited repeat lengths and mutation rates. Taking into account age, the estimated mutation rates are lower than predicted among individuals with small alleles (inherited repeat lengths less than 100 CTGs), suggesting that these rates may be suppressed at the lower end of the disease-causing range. In this study, we propose that a length-specific effect operates within this range and tested this hypothesis using a model comparison approach. To calibrate the extended model, we used data derived from blood DNA from DM1 individuals and, for the first time, buccal DNA from HD individuals. In a novel application of this extended model, we identified individuals whose effective repeat length, with regards to somatic instability, is less than their actual repeat length. A plausible explanation for this distinction is that the expanded repeat tract is compromised by interruptions or other unusual features. We quantified effective length for a large cohort of DM1 individuals and showed that effective length better predicts age of onset than inherited repeat length, thus improving the genotype-phenotype correlation. Under the extended model, we removed some of the bias in mutation rates making them less length-dependent. Consequently, rates adjusted in this way will be better suited as quantitative traits to investigate cis- or trans-acting modifiers of somatic mosaicism, disease onset and progression.
Collapse
Affiliation(s)
- Catherine F Higham
- School of Mathematics and Statistics, College of Science and Engineering, University of Glasgow, Glasgow G12 8QQ, UK.
| | | |
Collapse
|
23
|
Panaite PA, Kuntzer T, Gourdon G, Barakat-Walter I. Respiratory failure in a mouse model of myotonic dystrophy does not correlate with the CTG repeat length. Respir Physiol Neurobiol 2013; 189:22-6. [PMID: 23811192 DOI: 10.1016/j.resp.2013.06.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 06/20/2013] [Accepted: 06/20/2013] [Indexed: 01/03/2023]
Abstract
Myotonic dystrophy (DM1) is a multisystemic disease caused by an expansion of CTG repeats in the region of DMPK, the gene encoding DM protein kinase. The severity of muscle disability in DM1 correlates with the size of CTG expansion. As respiratory failure is one of the main causes of death in DM1, we investigated the correlation between respiratory impairment and size of the (CTG)n repeat in DM1 animal models. Using pressure plethysmography the respiratory function was assessed in control and transgenic mice carrying either 600 (DM600) or >1300 CTG repeats (DMSXL). The statistical analysis of respiratory parameters revealed that both DM1 transgenic mice sub-lines show respiratory impairment compared to control mice. In addition, there is no significant difference in breathing functions between the DM600 and DMSXL mice. In conclusion, these results indicate that respiratory impairment is present in both transgenic mice sub-lines, but the severity of respiratory failure is not related to the size of the (CTG)n expansion.
Collapse
|
24
|
Santoro M, Masciullo M, Pietrobono R, Conte G, Modoni A, Bianchi MLE, Rizzo V, Pomponi MG, Tasca G, Neri G, Silvestri G. Molecular, clinical, and muscle studies in myotonic dystrophy type 1 (DM1) associated with novel variant CCG expansions. J Neurol 2012; 260:1245-57. [PMID: 23263591 DOI: 10.1007/s00415-012-6779-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 11/22/2012] [Accepted: 11/28/2012] [Indexed: 12/15/2022]
Abstract
We assessed clinical, molecular and muscle histopathological features in five unrelated Italian DM1 patients carrying novel variant pathological expansions containing CCG interruptions within the 3'-end of the CTG array at the DMPK locus, detected by bidirectional triplet primed PCR (TP-PCR) and sequencing. Three patients had a negative DM1 testing by routine long-range PCR; the other two patients were identified among 100 unrelated DM1 cases and re-evaluated to estimate the prevalence of variant expansions. The overall prevalence was 4.8 % in our study cohort. There were no major clinical differences between variant and non-variant DM1 patients, except for cognitive involvement. Muscle RNA-FISH, immunofluorescence for MBNL1 and RT-PCR analysis documented the presence of ribonuclear inclusions, their co-localization with MBNL1, and an aberrant splicing pattern involved in DM1 pathogenesis, without any obvious differences between variant and non-variant DM1 patients. Therefore, this study shows that the CCG interruptions at the 3'-end of expanded DMPK alleles do not produce qualitative effects on the RNA-mediated toxic gain-of-function in DM1 muscle tissues. Finally, our results support the conclusion that different patterns of CCG interruptions within the CTG array could modulate the DM1 clinical phenotype, variably affecting the mutational dynamics of the variant repeat.
Collapse
|
25
|
Panaite PA, Kuntzer T, Gourdon G, Lobrinus JA, Barakat-Walter I. Functional and histopathological identification of the respiratory failure in a DMSXL transgenic mouse model of myotonic dystrophy. Dis Model Mech 2012. [PMID: 23180777 PMCID: PMC3634646 DOI: 10.1242/dmm.010512] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Acute and chronic respiratory failure is one of the major and potentially life-threatening features in individuals with myotonic dystrophy type 1 (DM1). Despite several clinical demonstrations showing respiratory problems in DM1 patients, the mechanisms are still not completely understood. This study was designed to investigate whether the DMSXL transgenic mouse model for DM1 exhibits respiratory disorders and, if so, to identify the pathological changes underlying these respiratory problems. Using pressure plethysmography, we assessed the breathing function in control mice and DMSXL mice generated after large expansions of the CTG repeat in successive generations of DM1 transgenic mice. Statistical analysis of breathing function measurements revealed a significant decrease in the most relevant respiratory parameters in DMSXL mice, indicating impaired respiratory function. Histological and morphometric analysis showed pathological changes in diaphragmatic muscle of DMSXL mice, characterized by an increase in the percentage of type I muscle fibers, the presence of central nuclei, partial denervation of end-plates (EPs) and a significant reduction in their size, shape complexity and density of acetylcholine receptors, all of which reflect a possible breakdown in communication between the diaphragmatic muscles fibers and the nerve terminals. Diaphragm muscle abnormalities were accompanied by an accumulation of mutant DMPK RNA foci in muscle fiber nuclei. Moreover, in DMSXL mice, the unmyelinated phrenic afferents are significantly lower. Also in these mice, significant neuronopathy was not detected in either cervical phrenic motor neurons or brainstem respiratory neurons. Because EPs are involved in the transmission of action potentials and the unmyelinated phrenic afferents exert a modulating influence on the respiratory drive, the pathological alterations affecting these structures might underlie the respiratory impairment detected in DMSXL mice. Understanding mechanisms of respiratory deficiency should guide pharmaceutical and clinical research towards better therapy for the respiratory deficits associated with DM1.
Collapse
|
26
|
Tabebordbar M, Wang ET, Wagers AJ. Skeletal muscle degenerative diseases and strategies for therapeutic muscle repair. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2012; 8:441-75. [PMID: 23121053 DOI: 10.1146/annurev-pathol-011811-132450] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Skeletal muscle is a highly specialized, postmitotic tissue that must withstand chronic mechanical and physiological stress throughout life to maintain proper contractile function. Muscle damage or disease leads to progressive weakness and disability, and manifests in more than 100 different human disorders. Current therapies to treat muscle degenerative diseases are limited mostly to the amelioration of symptoms, although promising new therapeutic directions are emerging. In this review, we discuss the pathological basis for the most common muscle degenerative diseases and highlight new and encouraging experimental and clinical opportunities to prevent or reverse these afflictions.
Collapse
Affiliation(s)
- Mohammadsharif Tabebordbar
- Department of Stem Cell and Regenerative Biology, Harvard University and Harvard Stem Cell Institute, Cambridge, MA 02138, USA.
| | | | | |
Collapse
|
27
|
Miró J, Gertz KJ, Carter GT, Jensen MP. Chronic pain in neuromuscular disease: pain site and intensity differentially impacts function. Phys Med Rehabil Clin N Am 2012; 23:895-902. [PMID: 23137744 DOI: 10.1016/j.pmr.2012.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The importance of pain extent (ie, number of body areas with pain) and pain site as factors contributing to dysfunction in persons with chronic, slowly progressive neuromuscular disease (NMD), remains poorly understood. This article discusses the importance of assessing pain site in addition to global pain intensity in patients with chronic, slowly progressive NMD. The importance of addressing pain at multiple sites will have a major impact on future studies assessing interventions to treat pain in this patient population.
Collapse
Affiliation(s)
- Jordi Miró
- Unit for the Study and Treatment of Pain-ALGOS, Centre de Recerca en Avaluació i Mesura del Comportament, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Catalonia, Spain
| | | | | | | |
Collapse
|
28
|
Best practice guidelines and recommendations on the molecular diagnosis of myotonic dystrophy types 1 and 2. Eur J Hum Genet 2012; 20:1203-8. [PMID: 22643181 PMCID: PMC3499739 DOI: 10.1038/ejhg.2012.108] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Myotonic dystrophy is an autosomal dominant, multisystem disorder that is characterized by myotonic myopathy. The symptoms and severity of myotonic dystrophy type l (DM1) ranges from severe and congenital forms, which frequently result in death because of respiratory deficiency, through to late-onset baldness and cataract. In adult patients, cardiac conduction abnormalities may occur and cause a shorter life span. In subsequent generations, the symptoms in DM1 may present at an earlier age and have a more severe course (anticipation). In myotonic dystrophy type 2 (DM2), no anticipation is described, but cardiac conduction abnormalities as in DM1 are observed and patients with DM2 additionally have muscle pain and stiffness. Both DM1 and DM2 are caused by unstable DNA repeats in untranslated regions of different genes: A (CTG)n repeat in the 3'-UTR of the DMPK gene and a (CCTG)n repeat in intron 1 of the CNBP (formerly ZNF9) gene, respectively. The length of the (CTG)n repeat expansion in DM1 correlates with disease severity and age of onset. Nevertheless, these repeat sizes have limited predictive values on individual bases. Because of the disease characteristics in DM1 and DM2, appropriate molecular testing and reporting is very important for the optimal counseling in myotonic dystrophy. Here, we describe best practice guidelines for clinical molecular genetic analysis and reporting in DM1 and DM2, including presymptomatic and prenatal testing.
Collapse
|
29
|
Morales F, Couto JM, Higham CF, Hogg G, Cuenca P, Braida C, Wilson RH, Adam B, del Valle G, Brian R, Sittenfeld M, Ashizawa T, Wilcox A, Wilcox DE, Monckton DG. Somatic instability of the expanded CTG triplet repeat in myotonic dystrophy type 1 is a heritable quantitative trait and modifier of disease severity. Hum Mol Genet 2012; 21:3558-67. [DOI: 10.1093/hmg/dds185] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
30
|
Higham CF, Morales F, Cobbold CA, Haydon DT, Monckton DG. High levels of somatic DNA diversity at the myotonic dystrophy type 1 locus are driven by ultra-frequent expansion and contraction mutations. Hum Mol Genet 2012; 21:2450-63. [PMID: 22367968 DOI: 10.1093/hmg/dds059] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Several human genetic diseases are associated with inheriting an abnormally large unstable DNA simple sequence repeat. These sequences mutate, by changing the number of repeats, many times during the lifetime of those affected, with a bias towards expansion. These somatic changes lead not only to the presence of cells with different numbers of repeats in the same tissue, but also produce increasingly longer repeats, contributing towards the progressive nature of the symptoms. Modelling the progression of repeat length throughout the lifetime of individuals has potential for improving prognostic information as well as providing a deeper understanding of the underlying biological process. A large data set comprising blood DNA samples from individuals with one such disease, myotonic dystrophy type 1, provides an opportunity to parameterize a mathematical model for repeat length evolution that we can use to infer biological parameters of interest. We developed new mathematical models by modifying a proposed stochastic birth process to incorporate possible contraction. A hierarchical Bayesian approach was used as the basis for inference, and we estimated the distribution of mutation rates in the population. We used model comparison analysis to reveal, for the first time, that the expansion bias observed in the distributions of repeat lengths is likely to be the cumulative effect of many expansion and contraction events. We predict that mutation events can occur as frequently as every other day, which matches the timing of regular cell activities such as DNA repair and transcription but not DNA replication.
Collapse
Affiliation(s)
- Catherine F Higham
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
| | | | | | | | | |
Collapse
|
31
|
Garcia Planells J, Molano J, Borrego S. [Recommendations of good practices for the genetic diagnosis of myotonic dystrophy. Grupo AEGH/CIBERER]. Med Clin (Barc) 2011; 136:303-8. [PMID: 20863536 DOI: 10.1016/j.medcli.2010.04.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Revised: 04/16/2010] [Accepted: 04/20/2010] [Indexed: 10/19/2022]
|
32
|
Braida C, Stefanatos RK, Adam B, Mahajan N, Smeets HJ, Niel F, Goizet C, Arveiler B, Koenig M, Lagier-Tourenne C, Mandel JL, Faber CG, de Die-Smulders CE, Spaans F, Monckton DG. Variant CCG and GGC repeats within the CTG expansion dramatically modify mutational dynamics and likely contribute toward unusual symptoms in some myotonic dystrophy type 1 patients. Hum Mol Genet 2010; 19:1399-412. [DOI: 10.1093/hmg/ddq015] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
|
33
|
Musova Z, Mazanec R, Krepelova A, Ehler E, Vales J, Jaklova R, Prochazka T, Koukal P, Marikova T, Kraus J, Havlovicova M, Sedlacek Z. Highly unstable sequence interruptions of the CTG repeat in the myotonic dystrophy gene. Am J Med Genet A 2009; 149A:1365-74. [DOI: 10.1002/ajmg.a.32987] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
34
|
Myotonic Dystrophy Transgenic Mice Exhibit Pathologic Abnormalities in Diaphragm Neuromuscular Junctions and Phrenic Nerves. J Neuropathol Exp Neurol 2008; 67:763-72. [DOI: 10.1097/nen.0b013e318180ec64] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
35
|
Gharehbaghi-Schneli EB, Finsterei J, Korschineck I, Mamoli B, Binder BR. Genotype -phenotype correlation in myotonic dystrophy. Clin Genet 2008. [DOI: 10.1111/j.1399-0004.1998.tb02576.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
36
|
Abstract
In the past few years, a new type of genetic mutation, expansion of trinucleotide repeats, has been shown to cause neurologic disease. This new class of mutations was first identified in 1991 as the underlying genetic defect in spinal and bulbar muscular atrophy and the fragile X syndrome, and in recent years, trinucleotide repeat expansions have been found to be the causative mechanism in 10 other neurologic diseases. These mutations are produced by heritable unstable DNA and are termed "dynamic mutations" because of changes in the number of repeat units inherited from generation to generation. In the normal population, these repeat units, although polymorphic, are stably inherited. To date four types of trinucleotide repeat expansions have been identified: (1) long cytosine-guanine-guanine (CGG) repeats in the two fragile X syndromes (FRAXA and FRAXE), (2) long cytosine-thymine-guanine (CTG) repeat expansions in myotonic dystrophy, (3) long guanine-adenine-adenine repeat expansions in Friedreich's ataxia and (4) short cytosine-adenine-guanine repeat expansions (CAG) which are implicated in eight neurodegenerative disorders and are the focus of this review. Diseases that are caused by trinucleotide repeat expansions exhibit a phenomenon called anticipation that can not be explained by conventional Mendelian genetics. Anticipation is defined as increase in the severity of disease with an earlier age of onset of symptoms in successive generations. Anticipation is often influenced by the sex of the transmitting parent, and for most CAG repeat disorders, the disease is more severe when paternally transmitted. The severity and the age of onset of the disease have been correlated with the size of the repeats on mutant alleles, with the age of onset being inversely correlated with the size of the expansion. In all eight disorders caused by CAG repeat expansion, the repeat is located within the coding region of the gene involved and in all cases it is translated into a stretch of polyglutamines in the respective proteins. All the proteins are unrelated outside of the polyglutamine stretch and most are novel with exception of the androgen receptor and the voltage gated alpha 1A calcium channel, which are mutated in spinal and bulbar muscular atrophy and spinocerebellar ataxia type 6. It is intriguing that the proteins are ubiquitously expressed in both peripheral and nervous tissue but in each disorder only a select population of nerve cells are targeted for degeneration as a consequence of the expanded CAG repeat. Current thinking among scientists working on the molecular mechanisms of neurodegeneration in these diseases is that the presence of an expanded polyglutamine confers a gain of function onto the involved protein. To understand the mechanisms underlying the pathogenesis of these diseases, investigators have turned to generating transgenic mice which recapitulate some of the features of the human disease and hence are excellent model systems to study the progression of the disease in vivo.
Collapse
Affiliation(s)
- B T Koshy
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030, USA
| | | |
Collapse
|
37
|
Abstract
Steinert disease, also known as myotonic dystrophy type 1, is a muscle disease characterized by myotonia and by multiorgan damage that combines various degrees of muscle weakness, arrhythmia and/or cardiac conduction disorders, cataract, endocrine damage, sleep disorders and baldness. It is the most frequent of the adult-onset muscular dystrophies; its prevalence is estimated at 1/20,000 inhabitants. Diagnosis is confirmed by the demonstration of an abnormality at the 19q13-2 locus, with the use of molecular genetic techniques. Its transmission is autosomal dominant, and anticipation may occur, that is, disease may be more severe and occur earlier in offspring. Genetic counseling is often delicate for this condition because of the great variability of clinical expression, both within and between families. Prenatal diagnosis is proposed especially for maternal transmission because of the severity of the possible neonatal forms. Management ideally includes multidisciplinary annual follow-up. Disease course is usually slowly progressive but rapid deterioration may sometimes be observed. Life expectancy is reduced by the increased mortality associated with the pulmonary and cardiac complications.
Collapse
Affiliation(s)
- Françoise Bouhour
- Service d'ENMG et pathologies neuromusculaires, Hôpital neurologique, Bron (69), France.
| | | | | |
Collapse
|
38
|
Jung SH, Bang MS. Belated diagnosis of congenital myotonic dystrophy in a boy with cerebral palsy. Am J Phys Med Rehabil 2007; 86:161-5. [PMID: 17251698 DOI: 10.1097/phm.0b013e31802ee339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We report a boy affected by both congenital myotonic dystrophy (CDM) and cerebral palsy (CP). He was born preterm and suffered from recurrent respiratory distress and respiratory tract infections. He was diagnosed with spastic diplegic CP. During the follow-up, long faces that lacked expression with a drooping mouth, of him and his mother, led to a detailed diagnostic evaluation. His electrodiagnostic testing demonstrated myotonic discharges. Molecular genetic tests revealed that the boy had 1240 CTG repeats and that his mother had 220 repeats, which confirmed the diagnosis of maternally transmitted CDM. Considering the increased obstetric risk of myotonic dystrophy (DM1), children of mothers with DM1 are susceptible to develop disorders such as CP. Clinical suspicion of comorbid CDM should be raised in children with CP who show features suggestive of DM1.
Collapse
Affiliation(s)
- Se Hee Jung
- Department of Rehabilitation Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | | |
Collapse
|
39
|
Greenberg SA, Walsh RJ. Molecular diagnosis of inheritable neuromuscular disorders. Part II: Application of genetic testing in neuromuscular disease. Muscle Nerve 2005; 31:431-51. [PMID: 15704143 DOI: 10.1002/mus.20279] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Molecular genetic advances have led to refinements in the classification of inherited neuromuscular disease, and to methods of molecular testing useful for diagnosis and management of selected patients. Testing should be performed as targeted studies, sometimes sequentially, but not as wasteful panels of multiple genetic tests performed simultaneously. Accurate diagnosis through molecular testing is available for the vast majority of patients with inherited neuropathies, resulting from mutations in three genes (PMP22, MPZ, and GJB1); the most common types of muscular dystrophies (Duchenne and Becker, facioscapulohumeral, and myotonic dystrophies); the inherited motor neuron disorders (spinal muscular atrophy, Kennedy's disease, and SOD1 related amyotrophic lateral sclerosis); and many other neuromuscular disorders. The role of potential multiple genetic influences on the development of acquired neuromuscular diseases is an increasingly active area of research.
Collapse
Affiliation(s)
- Steven A Greenberg
- Department of Neurology, Division of Neuromuscular Disease, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, Massachusetts 02115, USA.
| | | |
Collapse
|
40
|
Jinnai K, Nishimoto K, Itoh K, Hashimoto K, Takahashi K. Association of spinal and bulbar muscular atrophy with myotonic dystrophy type 1. Muscle Nerve 2004; 29:729-33. [PMID: 15116379 DOI: 10.1002/mus.10556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A man with spinal and bulbar muscular atrophy (SBMA) had a short (CTG)n expansion in the myotonic dystrophy protein kinase gene as well as (CAG)n expansion in the androgen receptor gene in leukocytes. The patient had the characteristic clinical findings of SBMA, but none of myotonic dystrophy type 1 (DM1). All of his three children (a son and two daughters) had the DM1 phenotype with long (CTG)n expansions. The daughters also had heterozygous long (CAG)n expansions. Postmortem examination of the patient revealed the characteristic pathological changes of SBMA as well as muscle degeneration compatible with DM1. Gene analysis of the organs disclosed unstable long expansions of the (CTG)n repeats, in contrast to the stable (CAG)n expansions. We have assumed that SBMA and DM1 developed independently in our patient, but cannot exclude the possibility that interactive gene effects increased somatic instability.
Collapse
Affiliation(s)
- Kenji Jinnai
- Department of Neurology, National Hyogo-Chuo Hospital, 1314 Ohara, Sanda 669-1592, Japan.
| | | | | | | | | |
Collapse
|
41
|
Abstract
Penetrance and expressivity have been defined through clinical experience. Although penetrance is often seen as the end of the spectrum of expressivity, penetrance and expressivity are considered as distinct phenomena. A review of the known mechanisms underlying either penetrance or expressivity reveals that in most of the cases the same explanation is true for both phenomena. Some of the known mechanisms include modifier genes, the influence of the allele in trans, sex, and environmental factors. Although rapid progress has been made in understanding of the basis of incomplete penetrance and the differences of expressivity, they still remain unknown for most of the genetic disorders. In recent years, it has become evident that there is much in common between the classical Mendelian traits in which the inheritance has been seen as "simple" and most of the common diseases in which the inheritance is "complex." In both cases genetic and/or environmental factors are acting in a complex way.
Collapse
Affiliation(s)
- Joël Zlotogora
- Department of Community Genetics, Public Health Services, Ministry of Health, Israel
| |
Collapse
|
42
|
Matsuura T, Ashizawa T. Spinocerebellar ataxia type 10: a disease caused by a large ATTCT repeat expansion. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 516:79-97. [PMID: 12611436 DOI: 10.1007/978-1-4615-0117-6_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Tohru Matsuura
- Department of Neurology, Baylor College of Medicine and Veterans Affairs Medical Center, Houston, Texas 77030 USA
| | | |
Collapse
|
43
|
Arakawa K, Tomi H, Tobimatsu S, Kira JI. Middle latency auditory-evoked potentials in myotonic dystrophy: relation to the size of the CTG trinucleotide repeat and intelligent quotient. J Neurol Sci 2003; 207:31-6. [PMID: 12614928 DOI: 10.1016/s0022-510x(02)00354-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Major components of MLAEPs are thought to originate in the temporal lobe. Absence of the Pb potential has been demonstrated in MLAEPs in Alzheimer's disease and demented Parkinson's disease patients. To validate usefulness of middle latency auditory-evoked potentials (MLAEPs) in evaluating the central nervous system (CNS) involvement of myotonic dystrophy (MyD). METHODS MLAEPs were recorded in eight patients with MyD and nine normal control subjects. In the patient group, the size of the CTG triplet repeat expansion within the dystrophia myotonica protein kinase (DMPK) gene and the revised Wechsler Adult Intelligence Scale (WAIS-R) were also assessed. RESULTS The latency of the Nb potential showed a significant correlation with the size of the CTG repeat expansion (r=0.734, P=0.036). The Pb latency also tended to prolong according to CTG amplification (r=0.644, P=0.087). The amplitudes of Na and Pa significantly increased compared with those of normal control subjects (P=0.024 and 0.016, respectively). However, they did not correlate with IQ or CTG amplification. CONCLUSIONS Abnormal MLAEPs may indicate CNS involvement in MyD. Although the precise generating mechanisms of Nb are unclear, the correlation of Nb latency with CTG amplification suggests that MLAEPs can reflect the extent of genetic abnormality.
Collapse
Affiliation(s)
- Kenji Arakawa
- Department of Neurology, National Center of Neurology and Psychiatry, Tokyo, Japan.
| | | | | | | |
Collapse
|
44
|
Barber M, Eguiluz I, Plasencia W, Ramírez O. Distrofia miotónica de steinert y gestación. CLINICA E INVESTIGACION EN GINECOLOGIA Y OBSTETRICIA 2003. [DOI: 10.1016/s0210-573x(03)77257-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
45
|
Abstract
The number of neurodegenerative disorders associated with the expansion of DNA repeats, currently about 18, continues to increase as additional diseases caused by this novel type of mutation are identified. Typically, expanded repeats are biased toward further expansion upon intergenerational transmission, and disease symptoms show an earlier age of onset and greater severity as the length of the triplet repeat tract increases. Most diseases exhibit progressive neurological and/or muscular degeneration that can lead to total disability and death. As yet, no treatment exists for the genetic basis of any repeat disease. Given that the severity of these diseases is related to repeat tract length, reducing repeat lengths might delay the onset and reduce disease severity. Here, we test the hypothesis that the introduction of damage into DNA, which results in subsequent repair events, can lead to an increased rate of repeat deletion. Applying a sensitive genetic assay in Escherichia coli [Mut. Res. 502 (2002) 25], we demonstrate that certain DNA damaging agents, including EMS, ENU, UV light, and anticancer agents mitomycin C, cisplatin, and X-rays increase the rate of deletion of (CTG).(CAG) repeats in a length and orientation dependent fashion. In addition, oxidative damage to DNA also increases the deletion rate of repeats. These results suggest that a chemotherapeutic approach to the reduction in triplet repeat length may provide one possible rationale to slow, stop, or reverse the progression of these diseases.
Collapse
Affiliation(s)
- Vera I Hashem
- Laboratory of DNA Structure and Mutagenesis, Center for Genome Research, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, 2121 West Holcombe Blvd, Houston, TX 77030-3303, USA
| | | |
Collapse
|
46
|
Brisson D, Tremblay M, Prévost C, Laberge C, Puymirat J, Mathieu J. Sibship stability of genotype and phenotype in myotonic dystrophy. Clin Genet 2002; 62:220-5. [PMID: 12220437 DOI: 10.1034/j.1399-0004.2002.620306.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Myotonic dystrophy (DM1) is caused by an unstable CTG repeat expansion. Despite the evidence of birth order effect in congenital DM1, the expansion's dynamics among sibships is still unknown. The objective of this study was to determine phenotype and CTG repeat size variability in DM1 sibships, and to investigate their predictive values. We compared 86 sib pairs for CTG repeat, 61 for age at onset and 89 for DM1 phenotype. CTG repeats remained stable for 66 of the 86 sib pairs, including 25 of 27 maternal transmissions and 30 of 42 paternal transmissions. Variations of less than 10 years in the age at onset were observed in 44 of 61 sib pairs, including 16 of 18 maternal transmissions and 19 of 28 paternal transmissions. The same phenotypic severity or a variation of only one class was observed among 86 of the 89 sib pairs, including all of the 35 maternal transmissions and 30 of the 33 paternal transmissions. Birth order, intergenesic interval, oldest sib's CTG repeat or parental age and CTG repeat did not exert any significant influence. These results suggest that genotype and phenotype remained stable among sibs, although the paternal origin of the mutation seemed to reduce the predictability of the severity.
Collapse
Affiliation(s)
- D Brisson
- Community Genomic Medicine Center, University of Montreal, Chicoutimi Hospital, Québec, Canada.
| | | | | | | | | | | |
Collapse
|
47
|
Mashiach R, Rimon E, Achiron R. Tent-shaped mouth as a presenting symptom of congenital myotonic dystrophy. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2002; 20:312-313. [PMID: 12230465 DOI: 10.1046/j.1469-0705.2002.00785.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- R Mashiach
- Department of Obstetrics and Gynecology, Lis Maternity Hospital, Tel Hashomer, Israel
| | | | | |
Collapse
|
48
|
Zatz M. A biologia molecular contribuindo para a compreensão e a prevenção das doenças hereditárias. CIENCIA & SAUDE COLETIVA 2002. [DOI: 10.1590/s1413-81232002000100008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
O fim do seqüenciamento do genoma humano levanta inúmeras questões: Como o projeto genoma humano vai influenciar nossas vidas? Como a medicina tem se beneficiado do estudo dos genes? Quais são as aplicações práticas imediatas e o que se espera para o futuro? Quais são as implicações éticas? Este capítulo ilustra como as doenças genéticas têm contribuído para a compreensão do genoma humano. Ajuda-nos a entender como nossos genes funcionam quando normais e por que causam doenças quando alterados. Do ponto de vista prático, o estudo dos genes tem permitido o diagnóstico molecular para um número crescente de patologias, o que é fundamental para evitar outros exames invasivos, identificar casais em risco, e prevenir o nascimento de novos afetados. Além disso, discute-se quais são as perspectivas futuras em relação ao tratamento destas e de outras patologias genéticas incluindo a clonagem para fins terapêuticos e a utilização de células-tronco. Finalmente aborda as implicações éticas relacionadas ao uso de testes genéticos. Os benefícios de cada teste, principalmente para doenças de início tardio para as quais ainda não há tratamento, têm que ser discutidos exaustivamente com os consulentes antes de sua aplicação.
Collapse
|
49
|
Clarke NR, Kelion AD, Nixon J, Hilton-Jones D, Forfar JC. Does cytosine-thymine-guanine (CTG) expansion size predict cardiac events and electrocardiographic progression in myotonic dystrophy? HEART (BRITISH CARDIAC SOCIETY) 2001; 86:411-6. [PMID: 11559681 PMCID: PMC1729946 DOI: 10.1136/heart.86.4.411] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To assess whether the size of the cytosine-thymine-guanine (CTG) expansion mutation in myotonic dystrophy predicts progression of conduction system disease and cardiac events. DESIGN Longitudinal study involving ECG and clinical follow up over (mean (SD)) 4.8 (1.8) and 6.2 (1.9) years, respectively, of patients stratified by CTG expansion size (E0 to E4). PATIENTS 73 adult patients under annual review in a regional myotonic dystrophy clinic. Patients were grouped into E0/E1 (n = 25), E2 (n = 34), and E3/E4 (n = 14). RESULTS The proportion of patients with a QRS complex > 100 ms at baseline increased with the size of the CTG expansion (EO/E1, 4%; E2, 12%; E3/E4, 36%; p = 0.02). This trend was more pronounced at follow up (E0/E1, 4%; E2, 21%; E3/E4, 57%; p = 0.0004). The rate of widening of the QRS complex (ms/year) was similarly related to the size of the mutation (EO/E1, 0.4 (1.3); E2, 1.4 (2.5); E3/E4, 1.5 (1.6); p = 0.04). First degree atrioventricular block was present in 23% of patients at baseline and 34% at follow up, with no significant relation to expansion size. Seven patients suffered a cardiac event during follow up (sudden death in two, permanent pacemaker insertion in three, chronic atrial arrhythmia in two), of whom six were in CTG expansion group E2 or greater. Patients who experienced a cardiac event during follow up had more rapid rates of PR interval increase (9.9 (11.1) v 1.6 (2.9) ms/year; p = 0.008) and a trend to greater QRS complex widening (3.6 (4.5) v 0.9 (1.5) ms/year; p = 0.06) than those who did not. CONCLUSIONS Larger CTG expansions are associated with a higher rate of conduction disease progression and a trend to increased risk of cardiac events in myotonic dystrophy.
Collapse
Affiliation(s)
- N R Clarke
- Cardiology Department, John Radcliffe Hospital, Oxford Radcliffe NHS Trust, Oxford, UK.
| | | | | | | | | |
Collapse
|
50
|
Frisch R, Singleton KR, Moses PA, Gonzalez IL, Carango P, Marks HG, Funanage VL. Effect of triplet repeat expansion on chromatin structure and expression of DMPK and neighboring genes, SIX5 and DMWD, in myotonic dystrophy. Mol Genet Metab 2001; 74:281-91. [PMID: 11592825 DOI: 10.1006/mgme.2001.3229] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Myotonic dystrophy (DM), an autosomal dominant neuromuscular disease, is associated with expansion of a polymorphic (CTG)n repeat in the 3'-untranslated region of the DM protein kinase (DMPK) gene. The repeat expansion results in decreased levels of DMPK mRNA and protein, but the mechanism for this decreased expression is unknown. Loss of a nuclease-hypersensitive site in the region of the repeat expansion has been observed in muscle and skin fibroblasts from DM patients, indicating a change in local chromatin structure. This change in chromatin structure has been proposed as a mechanism whereby the expression of DMPK and neighboring genes, sine oculis homeobox (Drosophila) homolog 5 (SIX5) and dystrophia myotonica-containing WD repeat motif (DMWD), might be affected. We have developed a polymerase chain reaction (PCR)-based method to assay the chromatin sensitivity of the region adjacent to the repeat expansion in somatic cell hybrids carrying either normal or affected DMPK alleles and show that hybrids carrying expanded alleles exhibit decreased sensitivity to PvuII digestion in this region. Semiquantitative multiplex reverse transcriptase PCR (RT/PCR) assays of gene expression from the chromosomes carrying the expanded alleles showed marked reduction of DMPK mRNA, partial inhibition of SIX5 expression from a congenital DM chromosome, and no reduction of DMWD mRNA. Nested RT/PCR analysis of DMPK mRNA from somatic cell hybrids carrying the repeat expansions revealed that most of the DMPK transcripts expressed from the expanded alleles lacked exons 13 and 14, whereas full-length transcripts were expressed predominantly from the normal alleles. These results suggest that the CTG repeat expansion leads to a decrease in DMPK mRNA levels by affecting splicing at the 3' end of the DMPK pre-mRNA transcript.
Collapse
Affiliation(s)
- R Frisch
- Department of Medical Research, Nemours Children's Clinic, Wilmington, Delaware 19803, USA
| | | | | | | | | | | | | |
Collapse
|