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Investigation of RFC1 tandem nucleotide repeat locus in diverse neurodegenerative outcomes in an Indian cohort.
Tyagi, Nishu; Uppili, Bharathram; Sharma, Pooja; Parveen, Shaista; Saifi, Sheeba; Jain, Abhinav; Sonakar, Akhilesh; Ahmed, Istaq; Sahni, Shweta; Shamim, Uzma; Anand, Avni; Suroliya, Varun; Asokachandran, Vivekanand; Srivastava, Achal; Sivasubbu, Sridhar; Scaria, Vinod; Faruq, Mohammed.
Afiliación
  • Tyagi N; Genomics and Molecular Medicine Division, CSIR - Institute of Genomics and Integrative Biology, New Delhi, 110007, India.
  • Uppili B; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
  • Sharma P; Genomics and Molecular Medicine Division, CSIR - Institute of Genomics and Integrative Biology, New Delhi, 110007, India.
  • Parveen S; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
  • Saifi S; Genomics and Molecular Medicine Division, CSIR - Institute of Genomics and Integrative Biology, New Delhi, 110007, India.
  • Jain A; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
  • Sonakar A; Genomics and Molecular Medicine Division, CSIR - Institute of Genomics and Integrative Biology, New Delhi, 110007, India.
  • Ahmed I; Genomics and Molecular Medicine Division, CSIR - Institute of Genomics and Integrative Biology, New Delhi, 110007, India.
  • Sahni S; Genomics and Molecular Medicine Division, CSIR - Institute of Genomics and Integrative Biology, New Delhi, 110007, India.
  • Shamim U; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
  • Anand A; Department of Neurology, Neuroscience Centre, All India Institute of Medical Sciences (AIIMS), 110608, New Delhi, India.
  • Suroliya V; Genomics and Molecular Medicine Division, CSIR - Institute of Genomics and Integrative Biology, New Delhi, 110007, India.
  • Asokachandran V; Department of Neurology, Neuroscience Centre, All India Institute of Medical Sciences (AIIMS), 110608, New Delhi, India.
  • Srivastava A; Genomics and Molecular Medicine Division, CSIR - Institute of Genomics and Integrative Biology, New Delhi, 110007, India.
  • Sivasubbu S; Genomics and Molecular Medicine Division, CSIR - Institute of Genomics and Integrative Biology, New Delhi, 110007, India.
  • Scaria V; Department of Neurology, Neuroscience Centre, All India Institute of Medical Sciences (AIIMS), 110608, New Delhi, India.
  • Faruq M; Genomics and Molecular Medicine Division, CSIR - Institute of Genomics and Integrative Biology, New Delhi, 110007, India.
Neurogenetics ; 25(1): 13-25, 2024 Jan.
Article en En | MEDLINE | ID: mdl-37917284
An intronic bi-allelic pentanucleotide repeat expansion mutation, (AAGGG)400-2000, at AAAAG repeat locus in RFC1 gene, is known as underlying genetic cause in cases with cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS) and late-onset sporadic ataxia. Biallelic positive cases carry a common recessive risk haplotype, "AAGA," spanning RFC1 gene. In this study, our aim is to find prevalence of bi-allelic (AAGGG)exp in Indian ataxia and other neurological disorders and investigate the complexity of RFC1 repeat locus and its potential association with neurodegenerative diseases in Indian population-based cohorts. We carried out repeat number and repeat type estimation using flanking PCR and repeat primed PCR (AAAAG/AAAGG/AAGGG) in four Indian disease cohorts and healthy controls. Haplotype assessment of suspected cases was done by genotyping and confirmed by Sanger sequencing. Blood samples and consent of all the cases and detailed clinical details of positive cases were collected in collaboration with A.I.I.M.S. Furthermore, comprehension of RFC1 repeat locus and risk haplotype analysis in Indian background was performed on the NGS data of Indian healthy controls by ExpansionHunter, ExpansionHunter Denovo, and PHASE analysis, respectively. Genetic screening of RFC1-TNR locus in 1998 uncharacterized cases (SCA12: 87; uncharacterized ataxia: 1818, CMT: 93) and 564 heterogenous controls showed that the frequency of subjects with bi-allelic (AAGGG)exp are 1.15%, < 0.05%, 2.15%, and 0% respectively. Two RFC1 positive sporadic late-onset ataxia cases, one bi-allelic (AAGGG)exp and another, (AAAGG)~700/(AAGGG)exp, had recessive risk haplotype and CANVAS symptoms. Long normal alleles, 15-27, are significantly rare in ataxia cohort. In IndiGen control population (IndiGen; N = 1029), long normal repeat range, 15-27, is significantly associated with A3G3 and some rare repeat motifs, AGAGG, AACGG, AAGAG, and AAGGC. Risk-associated "AAGA" haplotype of the original pathogenic expansion of A2G3 was found associated with the A3G3 representing alleles in background population. Apart from bi-allelic (AAGGG)exp, we report cases with a new pathogenic expansion of (AAAGG)exp/(AAGGG)exp in RFC1 and recessive risk haplotype. We found different repeat motifs at RFC1 TNR locus, like AAAAG, AAAGG, AAAGGG, AAAAGG, AAGAG, AACGG, AAGGC, AGAGG, and AAGGG, in Indian background population except ACAGG and (AAAGG)n/(AAGGG)n. Our findings will help in further understanding the role of long normal repeat size and different repeat motifs, specifically AAAGG, AAAGGG, and other rare repeat motifs, at the RFC1 locus.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Enfermedades Vestibulares / Ataxia Cerebelosa / Enfermedades del Sistema Nervioso Periférico Límite: Humans Idioma: En Revista: Neurogenetics Asunto de la revista: GENETICA / NEUROLOGIA Año: 2024 Tipo del documento: Article País de afiliación: India Pais de publicación: Estados Unidos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Enfermedades Vestibulares / Ataxia Cerebelosa / Enfermedades del Sistema Nervioso Periférico Límite: Humans Idioma: En Revista: Neurogenetics Asunto de la revista: GENETICA / NEUROLOGIA Año: 2024 Tipo del documento: Article País de afiliación: India Pais de publicación: Estados Unidos