Publication: C9orf72 Hexanucleotide Repeat in Huntington-Like Patients: Systematic Review and Meta-Analysis
Issued Date
2020-11-02
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16648021
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2-s2.0-85096170056
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Mahidol University
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SCOPUS
Bibliographic Citation
Frontiers in Genetics. Vol.11, (2020)
Suggested Citation
Carlos Alva-Diaz, Christoper A. Alarcon-Ruiz, Kevin Pacheco-Barrios, Nicanor Mori, Josmel Pacheco-Mendoza, Bryan J. Traynor, Andrea Rivera-Valdivia, Pongtawat Lertwilaiwittaya, Thomas D. Bird, Mario Cornejo-Olivas C9orf72 Hexanucleotide Repeat in Huntington-Like Patients: Systematic Review and Meta-Analysis. Frontiers in Genetics. Vol.11, (2020). doi:10.3389/fgene.2020.551780 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/60395
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Title
C9orf72 Hexanucleotide Repeat in Huntington-Like Patients: Systematic Review and Meta-Analysis
Other Contributor(s)
Hospital Nacional Daniel Alcides Carrión
Universidad San Ignacio de Loyola
Universidad Cientifica del Sur
Instituto Nacional de Ciencias Neurologicas
Universidad Peruana Cayetano Heredia
VA Puget Sound Health Care System
University of Washington, Seattle
Faculty of Medicine, Siriraj Hospital, Mahidol University
National Institutes of Health (NIH)
Fogarty Interdisciplinary Cerebrovascular Diseases Training Program in South America
Fogarty Northern Pacific Global Health Fellows Program
Universidad San Ignacio de Loyola
Universidad Cientifica del Sur
Instituto Nacional de Ciencias Neurologicas
Universidad Peruana Cayetano Heredia
VA Puget Sound Health Care System
University of Washington, Seattle
Faculty of Medicine, Siriraj Hospital, Mahidol University
National Institutes of Health (NIH)
Fogarty Interdisciplinary Cerebrovascular Diseases Training Program in South America
Fogarty Northern Pacific Global Health Fellows Program
Abstract
© Copyright © 2020 Alva-Diaz, Alarcon-Ruiz, Pacheco-Barrios, Mori, Pacheco-Mendoza, Traynor, Rivera-Valdivia, Lertwilaiwittaya, Bird and Cornejo-Olivas. Introduction: Patients with Huntington-Like disorders (HLD) comprise a variety of allelic disorders sharing a Huntington phenotype. The hexanucleotide repeat expansion of the C9orf72 gene could explain part of the HLD etiology. We aimed to conduct a systematic review and meta-analysis looking for the frequency of the hexanucleotide repeat expansion of the C9orf72 gene in HLD patients. Methods: The protocol was registered on the International Prospective Register of Systematic Reviews database (PROSPERO) (registration number: CRD42018105465). The search was carried out in Medline, Scopus, Web of Science, and Embase in April 2018, and updated in July 2020. Observational studies reporting patients with HLD carrying the hexanucleotide repeat expansion in the C9orf72 gene were selected and reviewed; this process was duplicated. The cutoff threshold for considering the hexanucleotide expansion as a pathogenic variant was equal to or >30 G4C2 repeats. Cases with intermediate alleles with 20–29 repeat are also analyzed. Pooled frequency and 95% CI were calculated using random-effects models. Results: Nine out of 219 studies were selected, reporting 1,123 affected individuals with HLD. Among them, 18 individuals carried C9orf72 expansion, representing 1% (95% CI: 0–2%, I2 = 0%) of the pooled frequency. Seven selected studies came from European centers, one was reported at a US center, and one came from a South-African center. We identified five individuals carrying intermediate alleles representing 3% (95% CI: 0–14%, I2 = 78.5%). Conclusions: The frequency of C9orf72 unstable hexanucleotide repeat expansion in HLD patients is very low. Further studies with more accurate clinical data and from different ethnic backgrounds are needed to confirm this observation.