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Min YG, Yoo D, Lee JY. Characteristics of very late-onset dentatorubro-pallidoluysian atrophy: the oldest onset case and review of literature. Neurol Sci 2020; 42:377-380. [PMID: 32712730 DOI: 10.1007/s10072-020-04625-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 07/21/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Young Gi Min
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea
| | - Dallah Yoo
- Department of Neurology, Kyung Hee University Hospital, Seoul, South Korea
| | - Jee-Young Lee
- Department of Neurology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul National University College of Medicine, 20 Boramae-ro 5-gil, Dongjak-gu, Seoul, 07061, South Korea.
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2
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Souza GN, Kersting N, Krum-Santos AC, Santos ASP, Furtado GV, Pacheco D, Gonçalves TA, Saute JA, Schuler-Faccini L, Mattos EP, Saraiva-Pereira ML, Jardim LB. Spinocerebellar ataxia type 3/Machado-Joseph disease: segregation patterns and factors influencing instability of expanded CAG transmissions. Clin Genet 2016; 90:134-40. [PMID: 26693702 DOI: 10.1111/cge.12719] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 12/16/2015] [Accepted: 12/17/2015] [Indexed: 11/30/2022]
Abstract
Controversies about Mendelian segregation and CAG expansion (CAGexp) instabilities during meiosis in spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) need clarification. Additional evidence about these issues was obtained from the cohort of all SCA3/MJD individuals living in South Brazil. A survey was carried out to update information registered since 2001. Deaths were checked with the Public Information System, and data was made anonymous. Anticipation and delta-CAGexp from parent-offspring pairs, and delta-CAGexp between siblings were obtained. One hundred and fifty-nine families (94% of the entire registry) were retrieved, comprising 3725 living individuals as of 2015, 625 of these being symptomatic. Minimal prevalence was 6:100,000. Carriers of a CAGexp represented 65.6% of sibs in the genotyped offspring (p < 0.001). Median instability was larger among paternal than maternal transmissions, and instabilities correlated with anticipation (r = 0.38; p = 0.001). Age of the parent correlated to delta-CAGexp among 115 direct parent-offspring CAGexp transmissions (ρ = 0.23, p = 0.014). In 98 additional kindreds, the delta-CAGexp between 269 siblings correlated with their delta-of-age (ρ = 0.27, p < 0.0001). SCA3/MJD was associated with a segregation distortion favoring the expanded allele in our cohort. Instability of expansion during meiosis was weakly influenced by the age of the transmitting parent at the time of conception.
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Affiliation(s)
- G N Souza
- Programa de Pós-Graduação em Ciências Médicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - N Kersting
- Programa de Pós-Graduação em Ciências Médicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - A C Krum-Santos
- Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - A S P Santos
- Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - G V Furtado
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Laboratório de Identificação Genética, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - D Pacheco
- Faculdade de Serviço Social, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - T A Gonçalves
- Escola de Enfermagem, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - J A Saute
- Laboratório de Identificação Genética, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - L Schuler-Faccini
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Departamento de Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Instituto de Genética Médica Populacional (INAGEMP), Porto Alegre, Brazil
| | - E P Mattos
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Laboratório de Identificação Genética, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - M L Saraiva-Pereira
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Laboratório de Identificação Genética, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Instituto de Genética Médica Populacional (INAGEMP), Porto Alegre, Brazil.,Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - L B Jardim
- Programa de Pós-Graduação em Ciências Médicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Laboratório de Identificação Genética, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Instituto de Genética Médica Populacional (INAGEMP), Porto Alegre, Brazil.,Departamento de Medicina Interna, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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3
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Byrne S, Heverin M, Bede P, Elamin M, Hardiman O. Fecundity in ALS. Amyotroph Lateral Scler Frontotemporal Degener 2014; 15:204-6. [PMID: 24479554 DOI: 10.3109/21678421.2013.865237] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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4
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Tan EC, Lai PS. Molecular diagnosis of neurogenetic disorders involving trinucleotide repeat expansions. Expert Rev Mol Diagn 2014; 5:101-9. [PMID: 15723596 DOI: 10.1586/14737159.5.1.101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
There are more than 15 known neurogenetic disorders involving trinucleotide repeat expansion. Expanded repeats range from small expansions of 20-100 copies to larger expansions of up to several thousand units. These dynamic expansions result in variability in age of onset, degree of severity and clinical presentation. Individuals carrying alleles in the intermediate range, known as premutation alleles, are often asymptomatic, but can potentially transmit a further expanded allele to his/her offspring. For autosomal dominant adult-onset disorders, carriers are asymptomatic prior to disease onset. With current molecular tools, it is now possible to determine the presence and number of expanded repeats for accurate diagnosis, presymptomatic testing and carrier status screening. This review examines some of the current approaches for molecular diagnosis and discusses the issues unique to triplet repeat diseases.
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Affiliation(s)
- Ene-Choo Tan
- DSO National Laboratories, Population Genetics Programme, Defence Medical and Environmental Research Institute, 27 Medical Drive, 117510 Singapore.
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5
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Zheng YM, Li L, Zhou LM, Le F, Cai LY, Yu P, Zhu YR, Liu XZ, Wang LY, Li LJ, Lou YY, Xu XR, Lou HY, Zhu XM, Sheng JZ, Huang HF, Jin F. Alterations in the frequency of trinucleotide repeat dynamic mutations in offspring conceived through assisted reproductive technology. Hum Reprod 2013; 28:2570-80. [PMID: 23861482 DOI: 10.1093/humrep/det294] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
STUDY QUESTION How does the frequency of trinucleotide repeat dynamic mutations in offspring conceived through assisted reproductive technology (ART) compare with the frequency of these mutations in control offspring conceived from spontaneous pregnancies? SUMMARY ANSWER There is a slight increase in dynamic mutation instability in offspring conceived through ART compared with the naturally conceived offspring. WHAT IS KNOWN ALREADY There is evidence to suggest that ART can increase the risk of birth defects and karyotypic abnormalities. However, the accumulating evidence of an association between ART and de novo genetic aberrations is controversial. STUDY DESIGN, SIZE, DURATION A prospective clinical observational study was performed on 246 families recruited from an in vitro fertilisation (IVF) centre at a tertiary-care, university-affiliated teaching hospital from 2008 to 2012. The study included 147 ART families [75 IVF and 72 intracytoplasmic sperm injection (ICSI)] in the study group and 99 natural-conception families in the control group. PARTICIPANTS, SETTING, METHODS Parental, umbilical cord and infant peripheral blood samples were collected, and the trinucleotide repeats of the ATN1, AR, ATXN1, ATXN3, Huntington, DMPK and FMR-1 genes were investigated between the generations; these genes were chosen due to their ability to undergo dynamic mutation. The frequencies and sizes of the mutational repeats, as well as the intergenerational instability, were measured. MAIN RESULTS AND THE ROLE OF CHANCE In 2466 transmissions identified in the ART offspring, 2.11% (n = 52/2466) of the alleles were unstable upon transmission, while in the control group offspring, the frequency of dynamic mutation was 0.77% (n = 10/1300); this difference was statistically significant (P < 0.01). The unstable transmission alleles were detected in 32 (2.48%) of the 1288 alleles from the IVF offspring and in 20 (1.70%) of the 1178 alleles from the ICSI offspring; both of these frequencies were significantly different from that of naturally conceived offspring (0.77%) (P < 0.01 and P < 0.05, respectively). However, there were no significant differences in the sizes of the mutational repeats or in the rates of expansion or contraction among the three groups (P > 0.05). The repeat copy numbers of the examined genes were found to be within the normal ranges in all parents and infants. LIMITATIONS, REASONS FOR CAUTION One strength of our study is the relatively large sample size; we were able to detect mutations in seven common dynamic genes, and this large sample size allowed us to detect unstable alleles. Although we observed a clear alteration in the frequency of dynamic mutation in the ART offspring compared with controls, further studies are urgently needed to confirm this observation and determine the cause of this phenomenon. WIDER IMPLICATIONS OF THE FINDINGS DNA microsatellite analysis provides an important tool to assess genomic instability. In this study, we report an association between ART and the frequency of dynamic mutation. The instability could be a reflection of the core infertility problem, the controlled ovarian hyperstimulation and/or the in vitro culture conditions.
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Affiliation(s)
- Ying-Ming Zheng
- Department of Reproductive Endocrinology, Zhejiang University School of Medicine, Zhejiang, China
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6
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Nihei Y, Ito D, Okada Y, Akamatsu W, Yagi T, Yoshizaki T, Okano H, Suzuki N. Enhanced aggregation of androgen receptor in induced pluripotent stem cell-derived neurons from spinal and bulbar muscular atrophy. J Biol Chem 2013; 288:8043-8052. [PMID: 23364790 DOI: 10.1074/jbc.m112.408211] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Spinal and bulbar muscular atrophy (SBMA) is an X-linked motor neuron disease caused by a CAG repeat expansion in the androgen receptor (AR) gene. Ligand-dependent nuclear accumulation of mutant AR protein is a critical characteristic of the pathogenesis of SBMA. SBMA has been modeled in AR-overexpressing animals, but precisely how the polyglutamine (polyQ) expansion leads to neurodegeneration is unclear. Induced pluripotent stem cells (iPSCs) are a new technology that can be used to model human diseases, study pathogenic mechanisms, and develop novel drugs. We established SBMA patient-derived iPSCs, investigated their cellular biochemical characteristics, and found that SBMA-iPSCs can differentiate into motor neurons. The CAG repeat numbers in the AR gene of SBMA-iPSCs and also in the atrophin-1 gene of iPSCs derived from another polyQ disease, dentato-rubro-pallido-luysian atrophy (DRPLA), remain unchanged during reprogramming, long term passage, and differentiation, indicating that polyQ disease-associated CAG repeats are stable during maintenance of iPSCs. The level of AR expression is up-regulated by neuronal differentiation and treatment with the AR ligand dihydrotestosterone. Filter retardation assays indicated that aggregation of ARs following dihydrotestosterone treatment in neurons derived from SBMA-iPSCs increases significantly compared with neurological control iPSCs, easily recapitulating the pathological feature of mutant ARs in SBMA-iPSCs. This phenomenon was not observed in iPSCs and fibroblasts, thereby showing the neuron-dominant phenotype of this disease. Furthermore, the HSP90 inhibitor 17-allylaminogeldanamycin sharply decreased the level of aggregated AR in neurons derived from SBMA-iPSCs, indicating a potential for discovery and validation of candidate drugs. We found that SBMA-iPSCs possess disease-specific biochemical features and could thus open new avenues of research into not only SBMA, but also other polyglutamine diseases.
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Affiliation(s)
- Yoshihiro Nihei
- Department of Neurologyt, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Daisuke Ito
- Department of Neurologyt, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan.
| | - Yohei Okada
- Physiologyt, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan; Kanrinmaru Project, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Wado Akamatsu
- Physiologyt, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Takuya Yagi
- Department of Neurologyt, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Takahito Yoshizaki
- Department of Neurologyt, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hideyuki Okano
- Physiologyt, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Norihiro Suzuki
- Department of Neurologyt, School of Medicine, Keio University, Shinjuku-ku, Tokyo 160-8582, Japan
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7
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Germ-line CAG repeat instability causes extreme CAG repeat expansion with infantile-onset spinocerebellar ataxia type 2. Eur J Hum Genet 2012; 21:626-9. [PMID: 23047744 DOI: 10.1038/ejhg.2012.231] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The spinocerebellar ataxias (SCA) are a genetically and clinically heterogeneous group of diseases, characterized by dominant inheritance, progressive cerebellar ataxia and diverse extracerebellar symptoms. A subgroup of the ataxias is caused by unstable CAG-repeat expansions in their respective genes leading to pathogenic expansions of polyglutamine stretches in the encoded proteins. In general, unstable CAG repeats have an uninterrupted CAG repeat, whereas stable CAG repeats are either short or interrupted by CAA codons, which - like CAG codons - code for glutamine. Here we report on an infantile SCA2 patient who, due to germ-line CAG repeat instability in her father, inherited an extremely expanded CAG repeat in the SCA2 locus. Surprisingly, the expanded allele of the father was an interrupted CAG repeat sequence. Furthermore, analyses of single spermatozoa showed a high frequency of paternal germ-line repeat sequence instability of the expanded SCA2 locus.
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8
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Ouyang Y, He Z, Li L, Qin X, Zhao Y, Yuan L. Spinocerebellar ataxia type 31 exists in northeast China. J Neurol Sci 2012; 316:164-7. [PMID: 22353852 DOI: 10.1016/j.jns.2012.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 01/30/2012] [Accepted: 02/01/2012] [Indexed: 10/28/2022]
Abstract
Spinocerebellar ataxia type 31 (SCA31), is a recently defined subtype of autosomal dominant cerebellar ataxia (ADCA) characterized by late-onset pure cerebellar ataxia. SCA31 is common in Japan but whether or not it exists in other countries is still unclear. In this study, the authors describe a sporadic Chinese patient with SCA31. Although the cardinal clinical features, i.e., late-onset cerebellar ataxia and hearing impairment in our sporadic patient were similar to those described previously in Japan, mild axonal sensorimotor neuropathy was identified in our SCA31 patient, which is somewhat distinct from most prior reports of the disease. This is the first report of SCA31 in China; thus, extending the ethnic association beyond families of Japanese origin. In addition, our study suggests that the clinical features of SCA31 might be broader than previously thought.
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Affiliation(s)
- Yi Ouyang
- Department of Neurology, First Affiliated Hospital, China Medical University, Shenyang 110001, Liaoning Province, China
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9
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Ouyang Y, Sakoe K, Shimazaki H, Namekawa M, Ogawa T, Ando Y, Kawakami T, Kaneko J, Hasegawa Y, Yoshizawa K, Amino T, Ishikawa K, Mizusawa H, Nakano I, Takiyama Y. 16q-linked autosomal dominant cerebellar ataxia: a clinical and genetic study. J Neurol Sci 2006; 247:180-6. [PMID: 16780885 DOI: 10.1016/j.jns.2006.04.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 03/24/2006] [Accepted: 04/19/2006] [Indexed: 12/30/2022]
Abstract
The autosomal dominant cerebellar ataxias (ADCAs) comprise a genetically and clinically heterogenous group of neurodegenerative disorders. Very recently, a C-to-T single nucleotide substitution in the puratrophin-1 gene was found to be strongly associated with a form of ADCA linked to chromosome 16q22.1 (16q-linked ADCA; OMIM 600223). We found the C-to-T substitution in the puratrophin-1 gene in 20 patients with ataxia (16 heterozygotes and four homozygotes) and four asymptomatic carriers in 9 of 24 families with an unknown type of ADCA. We also found two cases with 16q-linked ADCA among 43 sporadic patients with late-onset cortical cerebellar atrophy (LCCA). The mean age at onset in the 22 patients was 61.8 years, and that of homozygous patients was lower than that of heterozygous ones in one family. Neurological examination revealed that the majority of our patients showed exaggerated deep tendon reflexes in addition to the cardinal symptom of cerebellar ataxia (100%), and 37.5% of them had sensorineural hearing impairment, whereas sensory axonal neuropathy was absent. The frequency of 16q-linked ADCA was about 1/10 of our series of 110 ADCA families, making it the third most frequent ADCA in Japan.
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Affiliation(s)
- Y Ouyang
- Department of Neurology, Jichi Medical School, Tochigi 329-0498, Japan
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10
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Olejniczak M, Kozlowski P, Sobczak K, Krzyzosiak WJ. Accurate and sensitive analysis of triplet repeat expansions by capillary electrophoresis. Electrophoresis 2005; 26:2198-207. [PMID: 15861471 DOI: 10.1002/elps.200410197] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The reliable genetic diagnostics of triplet repeat expansions by capillary electrophoresis (CE) remains technically challenging due to the properties of the repeated GC-rich sequences. The biased base composition of the analyzed sample as compared to the commonly used DNA size standards makes the precise repeat length determination questionable. The homologous allelic ladders improve the accuracy of the repeat length analysis significantly. Their use, however, is not devoid of other complications. In the approach we propose, the allelic ladders are used only to properly calibrate the commercially available standards which serve then as internal standards in reliable and economical repeat length determination. In this study, we have also analyzed factors that could possibly increase the sensitivity of mutant allele detection by increasing the overall amplification efficiency and long-to-short product ratio.
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Affiliation(s)
- Marta Olejniczak
- Laboratory of Cancer Genetics, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
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11
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Savouret C, Garcia-Cordier C, Megret J, te Riele H, Junien C, Gourdon G. MSH2-dependent germinal CTG repeat expansions are produced continuously in spermatogonia from DM1 transgenic mice. Mol Cell Biol 2004; 24:629-37. [PMID: 14701736 PMCID: PMC343816 DOI: 10.1128/mcb.24.2.629-637.2004] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Myotonic dystrophy type 1 is a neuromuscular affection associated with the expansion of an unstable CTG repeat in the DM protein kinase gene. The disease is characterized by somatic tissue-specific mosaicism and very high intergenerational instability with a strong bias towards expansions. We used transgenic mice carrying more than 300 unstable CTG repeats within their large human genomic environment to investigate the dynamics of CTG repeat germinal mosaicism in males. Germinal mosaicism towards expansions was already present in spermatozoa at 7 weeks of age and continued to increase with age, suggesting that expansions are continuously produced throughout life. To determine the precise stage at which germinal expansions occur during spermatogenesis, we sorted and collected the different germ cell types produced during spermatogenesis from males of different ages and analyzed the CTG repeat mosaicism in each fraction. Strong mosaicisms towards expansions were already observed in spermatogonia before meiosis. In transgenic Msh2-deficient mice, germinal instability of the CTG repeats (only contractions) also occurs premeiotically. No significant difference in mosaicism was detected between spermatogonia and spermatozoa, arguing against continued expansions during postmeiotic stages. This indicates that germinal expansions are produced at the beginning of spermatogenesis, in spermatogonia, by a meiosis-independent mechanism involving MSH2.
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Affiliation(s)
- Cédric Savouret
- INSERM U383 Génétique, Chromosome et Cancer, Clinique M. Lamy 2ème étage, Hôpital Necker Enfants Malades, 149 rue de Sèvres, 75015 Paris, France
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12
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Arnheim N, Calabrese P, Nordborg M. Hot and cold spots of recombination in the human genome: the reason we should find them and how this can be achieved. Am J Hum Genet 2003; 73:5-16. [PMID: 12772086 PMCID: PMC1180590 DOI: 10.1086/376419] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2003] [Accepted: 04/10/2003] [Indexed: 11/03/2022] Open
Affiliation(s)
- Norman Arnheim
- Molecular and Computational Biology Program, University of Southern California, 835 West 37th Street, SHS 172, Los Angeles, CA 90089-1340, USA.
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13
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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
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14
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Hashida H, Goto J, Suzuki T, Jeong S, Masuda N, Ooie T, Tachiiri Y, Tsuchiya H, Kanazawa I. Single cell analysis of CAG repeat in brains of dentatorubral-pallidoluysian atrophy (DRPLA). J Neurol Sci 2001; 190:87-93. [PMID: 11574112 DOI: 10.1016/s0022-510x(01)00596-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Somatic mosaicism of an expanded repeat is present in tissues of patients with triplet repeat diseases. Of the spinocerebellar ataxias associated with triplet repeat expansion, the most prominent heterogeneity of the expanded repeat is seen in dentatorubral-pallidoluysian atrophy (DRPLA). The common feature of this somatic mosaicism is the difference in the repeat numbers found in the cerebellum as compared to other tissues. The expanded allele in the cerebellum shows a smaller degree of expansion. We previously showed by microdissection analysis that the expanded allele in the granular layer in DRPLA cerebellum has less expansion than expanded alleles in the molecular layer and white matter. Whether this feature of lesser expansion in granule cells is common to other types of neurons is yet to be clarified. We used a newly developed excimer laser microdissection system to analyze somatic mosaicism in the brains of two patients, one with early- and another with late-onset DRPLA, and used single cell PCR to observe the cell-to-cell differences in repeat numbers. In the late onset patient, repeat expansion was more prominent in Purkinje cells than in granule cells, but less than that in the glial cells. In the early onset patient, repeat expansion in Purkinje cells was greater than in granule cells but did not differ from that in glial cells. These findings suggest that there is a difference in repeat expansion among neuronal subgroups and that the number of cell division cycles is not the only determinant of somatic mosaicism.
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Affiliation(s)
- H Hashida
- CREST, Japan Science and Technology Corporation, Japan.
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15
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Abstract
Epilepsy may be acquired or inherited. At least one half of epilepsy is genetic in origin; this figure is likely higher in children regardless of whether seizures are generalized or partial. Inherited epilepsies are classified as benign, cryptogenic, or symptomatic depending on associated clinical, electrographic, and neuroimaging features. To date, genetic mutations in the idiopathic inherited epilepsies affect channel function within the central nervous system; genes underlying symptomatic epilepsies are more heterogeneous. Accurate diagnosis of an inherited epilepsy syndrome provides useful prognostic information; it also may help guide diagnostic evaluation, including request for specific gene testing. In the near future, the relationship between genetic defect and response to specific anticonvulsants may also be better defined.
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Affiliation(s)
- L E Walsh
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis 46202, USA
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16
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Kovtun IV, Goellner G, McMurray CT. Structural features of trinucleotide repeats associated with DNA expansion. Biochem Cell Biol 2001. [DOI: 10.1139/o01-101] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mechanism of DNA expansion is not well understood. Recent evidence from genetic, in vivo, and in vitro studies has suggested a link between the formation of alternative DNA secondary structures by trinucleotide repeat tracts and their propensity to undergo expansion. This review will focus on structural features and the mechanism of expansion relevant to human disease.Key words: expansion, hairpin, trinucleotide repeat, polymerase slippage, recombination, repair.
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17
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Sobrido MJ, Geschwind DH. Molecular Genetics and Inherited Ataxias: Redefining Phenotypes and Pathogenesis. Neuroscientist 2000. [DOI: 10.1177/107385840000600609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Genetic research on inherited ataxias has transformed our understanding of these conditions. The availability of genetic testing has shown that a classification based solely on clinical and pathologic findings is not adequate, and molecular genetic analysis is now mandatory for diagnostic accuracy and prognostic purposes. The epidemiology of these disorders is also being rewritten under the light of molecular genetic analysis. In this review, we discuss some of the recent advances on the hereditary cerebellar degenerations without a known metabolic defect, focusing on genotype-phenotype correlations in the spinocerebellar ataxias (SCAs) and Friedreich’s ataxia (FRDA). Three main biochemical pathways seem to be involved in the pathogenesis of inherited ataxias: 1) expansion of (CAG)n repeats within genes coding for polyglutamine-containing proteins (SCAs); 2) impairment of mitochondrial function (FRDA); and 3) dysfunction of ion channels (episodic ataxias, EA1, EA2). It is likely that many neurodegenerative conditions will prove to share basic molecular mechanisms, and therefore, data provided by the investigation of a particular disease is likely to be relevant to our global understanding of spinocerebellar degenerations and other degenerative disorders of the nervous system. A better knowledge of the molecular and cellular routes leading to neurodegeneration will provide a key to the design of rational therapies.
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Affiliation(s)
- Maria J. Sobrido
- Department of Neurology, Neurogenetics Program, University of California, Los Angeles, School of Medicine, Los Angeles, California
| | - Daniel H. Geschwind
- Department of Neurology, Neurogenetics Program, University of California, Los Angeles, School of Medicine, Los Angeles, California,
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Girardet A, McPeek MS, Leeflang EP, Munier F, Arnheim N, Claustres M, Pellestor F. Meiotic segregation analysis of RB1 alleles in retinoblastoma pedigrees by use of single-sperm typing. Am J Hum Genet 2000; 66:167-75. [PMID: 10631148 PMCID: PMC1288323 DOI: 10.1086/302715] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/1999] [Accepted: 09/29/1999] [Indexed: 12/18/2022] Open
Abstract
In hereditary retinoblastoma, different epidemiological studies have indicated a preferential paternal transmission of mutant retinoblastoma alleles to offspring, suggesting the occurrence of a meiotic drive. To investigate this mechanism, we analyzed sperm samples from six individuals from five unrelated families affected with hereditary retinoblastoma. Single-sperm typing techniques were performed for each sample by study of two informative short tandem repeats located either in or close to the retinoblastoma gene (RB1). The segregation probability of mutant RB1 alleles in sperm samples was assessed by use of the SPERMSEG program, which includes experimental parameters, recombination fractions between the markers, and segregation parameters. A total of 2,952 single sperm from the six donors were analyzed. We detected a significant segregation distortion in the data as a whole (P=.0099) and a significant heterogeneity in the segregation rate across donors (.0092). Further analysis shows that this result can be explained by segregation distortion in favor of the normal allele in one donor only and that it does not provide evidence of a significant segregation distortion in the other donors. The segregation distortion favoring the mutant RB1 allele does not seem to occur during spermatogenesis, and, thus, meiotic drive may result either from various mechanisms, including a fertilization advantage or a better mobility in sperm bearing a mutant RB1 gene, or from the existence of a defectively imprinted gene located on the human X chromosome.
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Affiliation(s)
- A Girardet
- Laboratoire de Génétique Moléculaire, Institut de Biologie, and Institut de Génétique Humaine, Centre National de la Recherche Scientifique, Unité Propre de Recherche 1142, 34060 Montpellier, France.
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Monckton DG, Cayuela ML, Gould FK, Brock GJ, Silva R, Ashizawa T. Very large (CAG)(n) DNA repeat expansions in the sperm of two spinocerebellar ataxia type 7 males. Hum Mol Genet 1999; 8:2473-8. [PMID: 10556295 DOI: 10.1093/hmg/8.13.2473] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Genetic anticipation, i.e. increasing disease severity and decreasing age of onset from one generation to the next, is observed in a number of diseases, including myotonic dystrophy type 1, Huntington's disease and several of the spinocerebellar ataxias. All of these disorders are associated with the expansion of a trinucleotide repeat and array length is positively correlated with disease severity and inversely correlated with the age of onset. The expanded repeat is highly unstable and continues to expand from one generation to the next, providing a molecular explanation for anticipation. Spinocerebellar ataxia type 7 (SCA7) is one of the latest additions to the list of triplet repeat diseases and is distinct from the other SCAs in that it is accompanied by retinal degeneration. Pedigree analyses have previously revealed that the SCA7 repeat is highly unstable and liable to expand, in particular when transmitted by a male. Surprisingly, though, an under-representation of male transmission has also been reported. We now demonstrate directly by single molecule analyses that the expanded repeat is extraordinarily unstable in the male germline and biased toward massive increases. Nearly all of the mutant sperm of two SCA7 males contain alleles that are so large that most of the affected offspring would at best have a severe infantile form of the disease. Indeed, the gross under-representation of such very large expanded alleles in patients suggests that a significant proportion of such alleles might be associated with embryonic lethality or dysfunctional sperm.
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Affiliation(s)
- D G Monckton
- Division of Molecular Genetics, Institute for Biomedical and Life Sciences, University of Glasgow, Anderson College, 56 Dumbarton Road, Glasgow G11 6NU, UK.
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Grewal RP, Cancel G, Leeflang EP, Dürr A, McPeek MS, Draghinas D, Yao X, Stevanin G, Alnot MO, Brice A, Arnheim N. French Machado-Joseph disease patients do not exhibit gametic segregation distortion: a sperm typing analysis. Hum Mol Genet 1999; 8:1779-84. [PMID: 10441343 DOI: 10.1093/hmg/8.9.1779] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Segregation distortion has been reported to occur in a number of the trinucleotide repeat disorders. On the basis of a sperm typing study performed in patients of Japanese descent with Machado-Joseph disease (MJD), it was reported that disease alleles are preferentially transmitted during meiosis. We performed a sperm typing study of five MJD patients of French descent and analysis of the pooled data shows a ratio of mutant to normal alleles of 379:436 (46.5:53.5%), which does not support meiotic segregation distortion. To confirm these results, sperm typing analysis was also performed using a polymorphic marker, D14S1050, closely linked to the MJD1 gene. Among 910 sperm analyzed, the allele linked to the disease chromosome was detected in 50.3% of the samples and the allele linked to the normal chromosome was found in 49.6% of the sperm. The difference in frequency of these two alleles is not significant ( P = 0.8423). Likelihood-based analysis of segregation distortion in the single sperm data using the SPERMSEG program also showed no support for segregation distortion at the gamete level in this patient population. The previous report on the Japanese patients also suggested that disease allele stability may be influenced by a trans effect of an intragenic polymorphism (987 G/C) in the wild-type allele. All of the French patients were heterozygous for this polymorphism. However, analysis of the variance in repeat number in sperm from the French MJD patients overlapped significantly with the variance in repeat number observed in the C/C homozygous Japanese patients.
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Affiliation(s)
- R P Grewal
- Program in Molecular Biology, SHS 172, 835 West 37th Street, University of Southern California, Los Angeles, CA 90089-1340, USA
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