65 results on '"Mazzetti, Pilar"'
Search Results
52. Rol del estado en los ensayos clínicos
- Author
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Mazzetti, Pilar, primary, Silva-Paredes, Gustavo, additional, and Cornejo-Olivas, Mario, additional
- Published
- 2012
- Full Text
- View/download PDF
53. The targetable A1 Huntington disease haplotype has distinct Amerindian and European origins in Latin America
- Author
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Kay, Chris, Tirado-Hurtado, Indira, Cornejo-Olivas, Mario, Collins, Jennifer A, Wright, Galen, Inca-Martinez, Miguel, Veliz-Otani, Diego, Ketelaar, Maria E, Slama, Ramy A, Ross, Colin J, Mazzetti, Pilar, and Hayden, Michael R
- Abstract
Huntington disease (HD) is a dominant neurodegenerative disorder caused by a CAG repeat expansion in the Huntingtin (HTT) gene. HD occurs worldwide, but the causative mutation is found on different HTT haplotypes in distinct ethnic groups. In Latin America, HD is thought to have European origins, but indigenous Amerindian ancestry has not been investigated. Here, we report dense HTT haplotypes in 62 mestizo Peruvian HD families, 17 HD families from across Latin America, and 42 controls of defined Peruvian Amerindian ethnicity to determine the origin of HD in populations of admixed Amerindian and European descent. HD in Peru occurs most frequently on the A1 HTT haplotype (73%), as in Europe, but on an unexpected indigenous variant also found in Amerindian controls. This Amerindian A1 HTT haplotype predominates over the European A1 variant among geographically disparate Latin American controls and in HD families from across Latin America, supporting an indigenous origin of the HD mutation in mestizo American populations. We also show that a proportion of HD mutations in Peru occur on a C1 HTT haplotype of putative Amerindian origin (14%). The majority of HD mutations in Latin America may therefore occur on haplotypes of Amerindian ancestry rather than on haplotypes resulting from European admixture. Despite the distinct ethnic ancestry of Amerindian and European A1 HTT, alleles on the parent A1 HTT haplotype allow for development of identical antisense molecules to selectively silence the HD mutation in the greatest proportion of patients in both Latin American and European populations.
- Published
- 2017
- Full Text
- View/download PDF
54. Clinical and Molecular Features of Late Onset Huntington Disease in a Peruvian Cohort.
- Author
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Velit-Salazar, Mario R., Mazzetti, Pilar, Cornejo-Olivas, Mario R., Inca-Martinez, Miguel A., Espinoza-Huertas, Keren, Veliz-Otani, Diego, Marca, Victoria, Ortega, Olimpio, Cornejo-Herrera, Ivan F., Lindo-Samanamud, Saul, and Mora-Alferez, Pamela
- Subjects
- *
HUNTINGTON disease , *CHOREA , *AGE of onset , *NUCLEOTIDE sequence , *COHORT analysis , *PATIENTS , *PROGNOSIS - Abstract
Background: Late onset cases of Huntington disease (HD), with onset ≥⃒60 years, account for up to 20% of HD cases worldwide. Clinical features include mild motor dysfunction with slow progression and cognitive impairment, frequent absence of family history and low number of CAG repeats. The clinical and molecular features of late onset HD is still understudied in Latin America. Objectives: To describe the clinical and molecular characteristics of late onset HD in a Peruvian cohort. Methods: An observational study was carried out by reviewing the HD registry at the Neurogenetics Research Center-INCN from 2000 to 2014. Genotyping of HTT gene was confirmed using standard PCR and PAGE in accordance to protocols previously established. Results: Thirty-one late onset HD cases from 27 pedigrees were identified (9.42% of total HD cases, n = 329), 51.61% were male. Mean age at onset was 64.1 ± 4.2 and CAG repeats mean was 42.5 ± 2.5. We did not find significant correlation between age at onset and CAG repeats. 33.3% of cases were traced back to Cañete valley. Twenty-two cases had a positive family history, 14 of them with paternal transmission. Choreic movements and cognitive impairment were the main existing manifestations reported in this cohort, with lower frequency of psychiatric disturbances. Conclusions: This report of late onset HD affected individuals shows a mild phenotype expression of the disease, associated with low range of CAG repeats and up to 30% of cases with absence of clear family history. Cañete valley remains the region with more cases. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
55. Polyneuropathy in autosomal dominant cerebellar ataxias: Phenotype-genotype correlation
- Author
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Kubis, Nathalie, primary, D�rr, Alexandra, additional, Gugenheim, Michel, additional, Chneiweiss, Herv�, additional, Mazzetti, Pilar, additional, Brice, Alexis, additional, and Bouche, Pierre, additional
- Published
- 1999
- Full Text
- View/download PDF
56. Genotyping strategy for the FMR1 gene: An alternative diagnostic method for the Fragile X syndrome and other trinucleotide expansion diseases.
- Author
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Lindo-Samanamud, Saúl, Cornejo-Olivas, Mario, Ortega, Olimpio, Marca, Victoria, Espinoza-Huertas, Keren, and Mazzetti, Pilar
- Published
- 2013
57. Polyneuropathy in autosomal dominant cerebellar ataxias: Phenotypegenotype correlation
- Author
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Kubis, Nathalie, Dürr, Alexandra, Gugenheim, Michel, Chneiweiss, Hervé, Mazzetti, Pilar, Brice, Alexis, and Bouche, Pierre
- Abstract
Autosomal dominant cerebellar ataxias (ADCAs) are clinically and genetically heterogeneous neurodegenerative disorders. The aim of this study was to evaluate electrophysiologically peripheral nervous system involvement in each of the groups studied and its correlation with the number of CAG repeats. Forty patients with ADCA were clinically and electrophysiologically investigated. Thirty-five patients belonged to the ADCA type I group (SCA1, 12; SCA2, 10; SCA3, 13) and five to the ADCA type II group. Axonal sensory or sensorimotor polyneuropathy was found in 42% of the SCA1 patients, 80% of the SCA2 patients, and 54% of the SCA3 patients, whereas electrophysiological studies were normal in all those with ADCA type II. The number of CAG repeats was significantly higher in SCA1 patients with polyneuropathy than in those without polyneuropathy (P = 0.01), whereas the reverse was observed in SCA3/MJD (MachadoJoseph disease) patients (P = 0.05). We conclude that axonal polyneuropathy is often associated with ADCA type I, but its frequency varies according to factors such as the locus responsible and the number of CAG repeats. © 1999 John Wiley & Sons, Inc. Muscle Nerve 22: 712717, 1999.
- Published
- 1999
- Full Text
- View/download PDF
58. Correction to: Genetic Analysis of Hereditary Ataxias in Peru Identifies SCA10 Families with Incomplete Penetrance.
- Author
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Cornejo-Olivas, Mario, Inca-Martinez, Miguel, Castilhos, Raphael Machado, Furtado, Gabriel Vasata, Mattos, Eduardo Preusser, Bampi, Giovana Bavia, Leistner-Segal, Sandra, Marca, Victoria, Mazzetti, Pilar, Saraiva-Pereira, Maria Luiza, and Jardim, Laura Bannach
- Subjects
FAMILIES - Abstract
The original version of this article unfortunately contained some mistakes in Table 2. The additional row (just above SCA2) with the following information "SCA1, 1(1), 1, 50, 74, 24, 46 and 0/1" should be inserted. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
59. Genome-Wide Analysis of Copy Number Variation in Latin American Parkinson's Disease Patients
- Author
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Sarihan, Elif Irem, Perez-Palma, Eduardo, Niestroj, Lisa-Marie, Loesch, Douglas, Inca-Martinez, Miguel, Horimoto, Andrea R. V. R., Cornejo-Olivas, Mario, Torres, Luis, Mazzetti, Pilar, Cosentino, Carlos, Sarapura-Castro, Elison, Rivera-Valdivia, Andrea, Dieguez, Elena, Raggio, Victor, Lescano, Andres, Tumas, Vitor, Borges, Vanderci, Ferraz, Henrique B., Rieder, Carlos R., Schumacher-Schuh, Artur F., Santos-Lobato, Bruno L., Velez-Pardo, Carlos, Jimenez-Del-Rio, Marlene, Lopera, Francisco, Moreno, Sonia, Chana-Cuevas, Pedro, Fernandez, William, Arboleda, Gonzalo, Arboleda, Humberto, Arboleda-Bustos, Carlos E., Yearout, Dora, Zabetian, Cyrus P., Thornton, Timothy A., O'Connor, Timothy D., Lal, Dennis, Mata, Ignacio F., Sarihan, Elif Irem, Perez-Palma, Eduardo, Niestroj, Lisa-Marie, Loesch, Douglas, Inca-Martinez, Miguel, Horimoto, Andrea R. V. R., Cornejo-Olivas, Mario, Torres, Luis, Mazzetti, Pilar, Cosentino, Carlos, Sarapura-Castro, Elison, Rivera-Valdivia, Andrea, Dieguez, Elena, Raggio, Victor, Lescano, Andres, Tumas, Vitor, Borges, Vanderci, Ferraz, Henrique B., Rieder, Carlos R., Schumacher-Schuh, Artur F., Santos-Lobato, Bruno L., Velez-Pardo, Carlos, Jimenez-Del-Rio, Marlene, Lopera, Francisco, Moreno, Sonia, Chana-Cuevas, Pedro, Fernandez, William, Arboleda, Gonzalo, Arboleda, Humberto, Arboleda-Bustos, Carlos E., Yearout, Dora, Zabetian, Cyrus P., Thornton, Timothy A., O'Connor, Timothy D., Lal, Dennis, and Mata, Ignacio F.
- Abstract
Background Parkinson's disease is the second most common neurodegenerative disorder and affects people from all ethnic backgrounds, yet little is known about the genetics of Parkinson's disease in non-European populations. In addition, the overall identification of copy number variants at a genome-wide level has been understudied in Parkinson's patients. The objective of this study was to understand the genome-wide burden of copy number variants in Latinos and its association with Parkinson's disease. Methods We used genome-wide genotyping data from 747 Parkinson's disease patients and 632 controls from the Latin American Research Consortium on the Genetics of Parkinson's disease. Results Genome-wide copy number burden analysis showed that patients were significantly enriched for copy number variants overlapping known Parkinson's disease genes compared with controls (odds ratio, 3.97; 95%CI, 1.69-10.5; P = 0.018). PRKN showed the strongest copy number burden, with 20 copy number variant carriers. These patients presented an earlier age of disease onset compared with patients with other copy number variants (median age at onset, 31 vs 57 years, respectively; P = 7.46 x 10(-7)). Conclusions We found that although overall genome-wide copy number variant burden was not significantly different, Parkinson's disease patients were significantly enriched with copy number variants affecting known Parkinson's disease genes. We also identified that of 250 patients with early-onset disease, 5.6% carried a copy number variant on PRKN in our cohort. Our study is the first to analyze genome-wide copy number variant association in Latino Parkinson's disease patients and provides insights about this complex disease in this understudied population. (c) 2020 International Parkinson and Movement Disorder Society
60. Genome-Wide Analysis of Copy Number Variation in Latin American Parkinson's Disease Patients
- Author
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Sarihan, Elif Irem, Perez-Palma, Eduardo, Niestroj, Lisa-Marie, Loesch, Douglas, Inca-Martinez, Miguel, Horimoto, Andrea R. V. R., Cornejo-Olivas, Mario, Torres, Luis, Mazzetti, Pilar, Cosentino, Carlos, Sarapura-Castro, Elison, Rivera-Valdivia, Andrea, Dieguez, Elena, Raggio, Victor, Lescano, Andres, Tumas, Vitor, Borges, Vanderci, Ferraz, Henrique B., Rieder, Carlos R., Schumacher-Schuh, Artur F., Santos-Lobato, Bruno L., Velez-Pardo, Carlos, Jimenez-Del-Rio, Marlene, Lopera, Francisco, Moreno, Sonia, Chana-Cuevas, Pedro, Fernandez, William, Arboleda, Gonzalo, Arboleda, Humberto, Arboleda-Bustos, Carlos E., Yearout, Dora, Zabetian, Cyrus P., Thornton, Timothy A., O'Connor, Timothy D., Lal, Dennis, Mata, Ignacio F., Sarihan, Elif Irem, Perez-Palma, Eduardo, Niestroj, Lisa-Marie, Loesch, Douglas, Inca-Martinez, Miguel, Horimoto, Andrea R. V. R., Cornejo-Olivas, Mario, Torres, Luis, Mazzetti, Pilar, Cosentino, Carlos, Sarapura-Castro, Elison, Rivera-Valdivia, Andrea, Dieguez, Elena, Raggio, Victor, Lescano, Andres, Tumas, Vitor, Borges, Vanderci, Ferraz, Henrique B., Rieder, Carlos R., Schumacher-Schuh, Artur F., Santos-Lobato, Bruno L., Velez-Pardo, Carlos, Jimenez-Del-Rio, Marlene, Lopera, Francisco, Moreno, Sonia, Chana-Cuevas, Pedro, Fernandez, William, Arboleda, Gonzalo, Arboleda, Humberto, Arboleda-Bustos, Carlos E., Yearout, Dora, Zabetian, Cyrus P., Thornton, Timothy A., O'Connor, Timothy D., Lal, Dennis, and Mata, Ignacio F.
- Abstract
Background Parkinson's disease is the second most common neurodegenerative disorder and affects people from all ethnic backgrounds, yet little is known about the genetics of Parkinson's disease in non-European populations. In addition, the overall identification of copy number variants at a genome-wide level has been understudied in Parkinson's patients. The objective of this study was to understand the genome-wide burden of copy number variants in Latinos and its association with Parkinson's disease. Methods We used genome-wide genotyping data from 747 Parkinson's disease patients and 632 controls from the Latin American Research Consortium on the Genetics of Parkinson's disease. Results Genome-wide copy number burden analysis showed that patients were significantly enriched for copy number variants overlapping known Parkinson's disease genes compared with controls (odds ratio, 3.97; 95%CI, 1.69-10.5; P = 0.018). PRKN showed the strongest copy number burden, with 20 copy number variant carriers. These patients presented an earlier age of disease onset compared with patients with other copy number variants (median age at onset, 31 vs 57 years, respectively; P = 7.46 x 10(-7)). Conclusions We found that although overall genome-wide copy number variant burden was not significantly different, Parkinson's disease patients were significantly enriched with copy number variants affecting known Parkinson's disease genes. We also identified that of 250 patients with early-onset disease, 5.6% carried a copy number variant on PRKN in our cohort. Our study is the first to analyze genome-wide copy number variant association in Latino Parkinson's disease patients and provides insights about this complex disease in this understudied population. (c) 2020 International Parkinson and Movement Disorder Society
61. ENFERMEDAD DE KENNEDY EN EL PERÚ: PRIMEROS CASOS CON DIAGNÓSTICO MOLECULAR.
- Author
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Gómez-Calero, Víctor, Cornejo-Olivas, Mario, Ortega, Olimpio, Marca, Victoria, Lindo-Samanamud, Saúl, Flores, Martha, Torres-Ramírez, Luis, and Mazzetti, Pilar
- Subjects
- *
NEUROMUSCULAR diseases , *MOLECULAR diagnosis , *GENETIC disorders , *MOTOR neuron diseases , *DISEASE progression , *GENETIC mutation , *ANDROGEN receptors - Abstract
Kennedy's disease is an X-linked recessive disorder with onset in adulthood, characterized by progressive degeneration of spinal motor neurons due to a dynamic mutation in the androgen receptor gene. We report three families (five cases) characterized by progressive weakness involving both limbs and bulbar muscles, atrophy, tremor, cramps and endocrinologic disturbances; the neurophysiological studies demonstrated second motor neuron impairment. The molecular analysis identified abnormal CAG repeats expansion in the androgen receptor gene (AR) in all cases. Clinical features were consistent with other previous reports. These are the first Peruvian cases of Kennedy's disease with confirmed molecular diagnosis. [ABSTRACT FROM AUTHOR]
- Published
- 2013
62. POLIMORFISMO GENÉTICO DE LA APOLIPOPROTEÍNA E EN UNA POBLACIÓN PERUANA.
- Author
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Marca, Victoria, Acosta, Oscar, Cornejo-Olivas, Mario, Ortega, Olimpio, Huerta, Doris, and Mazzetti, Pilar
- Subjects
- *
APOLIPOPROTEIN E , *GENETIC polymorphisms , *PERUVIANS , *GENE frequency , *CARDIOVASCULAR diseases risk factors , *POLYACRYLAMIDE gel electrophoresis , *POPULATION genetics , *CROSS-sectional method - Abstract
Objectives. To determine the allelic and genotypic frequencies of the APOE gene in a sample of a population group in Peru. Materials and methods. Cross-sectional analytic study in 189 apparently healthy volunteers, workers of the Instituto Nacional de Ciencias Neurológicas in Lima, Perú, divided into 5 groups by birth department and two generations ancestry. Genomic DNA was ampliied using PCR-RFLP. The resulting fragments were detected by 12 % polyacrylamide gel electrophoresis. Results. The ε3 allele is the most frequent in all the groups (93.9 %), with low ε4 (5 %) and ε2 (1.1 %) allele frequencies. The analysis of heterozygosity (H) for each group displays intermediate diversity between 10 and 20%. Population genetic diversity (Ht) and diversity within populations (Hs) are 14.43 % and 14.31% respectively, suggesting genetic proximity between the studied groups for the ApoE polymorphism. Conclusions. Allele frequencies of the ApoE gene found show that allele ε3 has one of the highest frequencies and ε4 allele one of the lowest compared to other population groups in the world, with possible implications in the risk of neurological, cardiovascular and other diseases in our country. [ABSTRACT FROM AUTHOR]
- Published
- 2011
63. [Kennedy disease in Peru: first cases with molecular diagnosis].
- Author
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Gómez-Calero V, Cornejo-Olivas M, Ortega O, Marca V, Lindo-Samanamud S, Flores M, Torres-Ramírez L, and Mazzetti P
- Subjects
- Adult, Aged, Humans, Male, Middle Aged, Pedigree, Peru, Bulbo-Spinal Atrophy, X-Linked diagnosis, Bulbo-Spinal Atrophy, X-Linked genetics
- Abstract
Kennedy's disease is an X-linked recessive disorder with onset in adulthood, characterized by progressive degeneration of spinal motor neurons due to a dynamic mutation in the androgen receptor gene. We report three families (five cases) characterized by progressive weakness involving both limbs and bulbar muscles, atrophy, tremor, cramps and endocrinologic disturbances; the neurophysiological studies demonstrated second motor neuron impairment. The molecular analysis identified abnormal CAG repeats expansion in the androgen receptor gene (AR) in all cases. Clinical features were consistent with other previous reports. These are the first Peruvian cases of Kennedy's disease with confirmed molecular diagnosis.
- Published
- 2013
64. [Role of government in clinical trials].
- Author
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Mazzetti P, Silva-Paredes G, and Cornejo-Olivas M
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- Humans, Role, Clinical Trials as Topic legislation & jurisprudence, Clinical Trials as Topic standards, Government
- Abstract
The regulation of clinical trials by the Government is a process of continuous change and adaptation, current challenge is to ensure the safety of participants and get balance of administrative procedures. Development and regulation of clinical trials in different countries vary according to the situation, context national or international execution, determining the insufficiency of national regulation requiring review of international regulation. The aim of this publication is to present a comprehensive overview of the role of Government in the regulation of clinical trials in different realities. It includes a review of the regulation in The European Union, The United States and some Latin American countries and finally the regulation in Peru. Contemporary trends in the regulation of clinical trials, are characterized by increasing standards of quality, ensuring the safety of the participants, promote transparency, lower bureaucratic processes and strengthening ethics IRB committees in the framework of open democratic processes, involving all stakeholders in dynamic processes based on current knowledge and changing tendencies. The challenge is to promote the development of clinical trials from the government institutions (universities, research centers, institutes, hospitals, etc.) priorizing local needs including orphan drugs, prevalent and neglected diseases, and therapeutic use of active components of local native plants.
- Published
- 2012
- Full Text
- View/download PDF
65. [Genetic polymorphism of apolipoprotein E in a Peruvian population].
- Author
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Marca V, Acosta O, Cornejo-Olivas M, Ortega O, Huerta D, and Mazzetti P
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Cross-Sectional Studies, Female, Gene Frequency, Humans, Male, Middle Aged, Peru, Young Adult, Apolipoproteins E genetics, Polymorphism, Genetic
- Abstract
Objectives: To determine the allelic and genotypic frequencies of the APOE gene in a sample of a population group in Peru., Materials and Methods: Cross-sectional analytic study in 189 apparently healthy volunteers, workers of the Instituto Nacional de Ciencias Neurológicas in Lima, Perú, divided into 5 groups by birth department and two generations ancestry. Genomic DNA was amplified using PCR-RFLP. The resulting fragments were detected by 12 % polyacrylamide gel electrophoresis., Results: The ε3 allele is the most frequent in all the groups (93.9 %), with low ε4 (5 %) and ε2 (1.1 %) allele frequencies. The analysis of heterozygosity (H) for each group displays intermediate diversity between 10 and 20%. Population genetic diversity (Ht) and diversity within populations (Hs) are 14.43 % and 14.31% respectively, suggesting genetic proximity between the studied groups for the ApoE polymorphism., Conclusions: Allele frequencies of the ApoE gene found show that allele ε3 has one of the highest frequencies and ε4 allele one of the lowest compared to other population groups in the world, with possible implications in the risk of neurological, cardiovascular and other diseases in our country.
- Published
- 2011
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