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BACKGROUND: Parkinson's disease (PD) is the second most common neurodegenerative disease following Alzheimer's disease. Nearly 30 causative genes have been identified for PD and related disorders. However, most of these genes were identified in European-derived families, and little is known about their role in Latin American populations. OBJECTIVES: Our goal was to assess the spectrum and frequency of pathogenic variants in known PD genes in familial PD patients from Latin America. METHODS: We selected 335 PD patients with a family history of PD from the Latin American Research Consortium on the Genetics of PD. We capture-sequenced the coding regions of 26 genes related to neurodegenerative parkinsonism. Of the 335 PD patients, 324 had sufficient sequencing coverage to be analyzed. RESULTS: We identified pathogenic variants in 41 individuals (12.7%) in FBXO7, GCH1, LRRK2, PARK7, PINK1, PLA2G6, PRKN, SNCA, and TARDBP, GBA1 risk variants in 25 individuals (7.7%), and variants of uncertain significance in another 24 individuals (7.4%) in ATP13A2, ATP1A3, DNAJC13, DNAJC6, GBA1, LRKK2, PINK1, VPS13C, and VPS35. Of the 70 unique variants identified, 19 were more frequent in Latin Americans than in any other population. CONCLUSIONS: This is the first screening of known PD genes in a large cohort of patients with familial PD from Latin America. There were substantial differences in the spectrum of variants observed in comparison to previous findings from PD families of European origin. Our data provide further evidence that differences exist between the genetic architecture of PD in Latinos and European-derived populations. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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SUMMARY Duchenne muscular dystrophy (DMD) is a rapidly progressive dystrophinopathy with X-linked inheritance. This report describes a woman with a family history of male relatives affected by DMD, as she sought out genetic counseling about her concerns related to family planning and risks of eventually having children with the disease. We proposed her to get involved in a pilot program for carrier-status diagnosis and genetic counseling. This case illustrates the importance of a genetic counseling program for diagnosis of asymptomatic carriers in neurogenetic diseases, particularly in regions with low-resource settings. We discussed successes and misunderstandings faced throughout the process, supporting policies for present and future challenges from this and similar kinds of diagnoses.
RESUMEN La distrofia muscular de Duchenne (DMD) es una distrofinopatía rápidamente progresiva con herencia ligada al cromosoma X. Este reporte describe el caso de una mujer con historia familiar de hermano y sobrinos con DMD, que acudió a consulta para orientación e información sobre riesgos inherentes a una eventual planificación familiar. Le propusimos participar en un programa piloto de asesoramiento genético para determinar su estado de portador o no de la variante causal de DMD en la familia. Esta primera experiencia ilustra la importancia de tener un programa de asesoramiento genético para el diagnóstico de portadores asintomáticos de enfermedades neurogenéticas en regiones con bajos recursos. Se incluyen reflexiones y comentarios sobre aspectos positivos y retos presentados durante el proceso, las políticas de apoyo presente y futuro para el afronte de los complejos problemas planteados por éste y similares diagnósticos.
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Introducción. La enfermedad de Parkinson (EP) es un trastorno neurodegenerativo común, el segundo más frecuente después de la enfermedad de Alzheimer. La mutación A53T en el gen SNCA, fue la primera identificada en asociación con EP. La mayoría de casos de EP en familias con esta mutación provienen de regiones cercanas al lugar del descubrimiento original. Objetivos: Evaluar la presencia de la mutación A53T en el gen SNCA en una muestra peruana de casos con EP de incidencia familiar, esporádicos y controles sanos. Material y Métodos: Se analizaron, mediante la técnica de PCR-RFLP, las muestras de ADN de 34 casos con EP esporádico, 7 casos de EP familiar y 32 individuos control. Resultados: No se encontró la mutación A53T en la muestra analizada, por lo que se infiere que ella estaría confinada a pocas familias de origen caucásico (europeo) asociadas a aquéllas con los casos originalmente descritos. Conclusiones: La mutación A53T no sería un factor causal o primario de EP en los casos evaluados.
Introduction. Parkinson's Disease (PD) is a common neurodegenerative disorder, the second most frequent after Alzheimer's Disease. The A53T mutation in the SNCA gene was the first one identified in association with PD. Most of familial PD cases with this mutation come from regions close to the original discovery site. Objectives: To evaluate the presence of the A53T-SNCA mutation in a Peruvian sample of Parkinson´s Disease cases familial, sporadic and healthy controls. Material and Methods: DNA samples from 34 cases with sporadic PD, 7 cases of familial PD, and 32 control individuals were analyzed by PCR-RFLP. Results: The A53T mutation was not found. This mutation would be confined to a few families of European or Caucasian origin linked to the cases originally described. Conclusions: The A53T mutation would not be the primary causal factor of PD in the evaluated cases
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La neurogenética es una disciplina emergente en el Perú que vincula la investigación básica con la práctica clínica. El Centro de Investigación Básica en Neurogenética, es el único centro en el Perú dedicado a la atención especializada de enfermedades neurogenéticas. La investigación en esta área está estrechamente ligada a la enfermedad de Huntington, desde la genotipificación del gen HTT por PCR, hasta los actuales estudios de haplogrupos en esta enfermedad. La investigación en otras enfermedades monogénicas permitió la implementación de metodologías alternativas para la genotipificación del síndrome X frágil y distrofia miotónica tipo 1. Esfuerzos colaborativos nacionales e internacionales han permitido conocer nuevas variantes genéticas en enfermedades complejas, como la enfermedad de Parkinson y Alzheimer. El entrenamiento multidisciplinario y la mentoría fomentan la formación de nuevos especialistas en neurogenética, permitiendo el crecimiento sostenido de esta disciplina en el país. El impulso de la investigación en el Perú ha impulsado el crecimiento de la investigación en neurogenética; sin embargo, las limitaciones en infraestructura, tecnología y capacitación aún son un reto para el crecimiento de investigación en esta disciplina...
Neurogenetics is an emerging discipline in Peru that links basic research with clinical practice. The Neurogenetics Research Center located in Lima, Peru is the only unit dedicated to the specialized care of neurogenetic diseases in the country. From the beginning, neurogenetics research has been closely linked to the study of HuntingtonÆs Disease (HD), from the PCR genotyping of the HTT gene, to the current haplogroup studies in HD. Research in other monogenic diseases led to the implementation of alternative methodologies for the genotyping of Fragile X and Myotonic Dystrophy Type 1. Both, national and international collaborative efforts have facilitated the discovery of new genetic variants in complex multigenic diseases such as ParkinsonÆs disease and AlzheimerÆs disease. Additionally, multidisciplinary education and mentoring have allowed for the training of new neurogenetics specialists, supporting the sustained growth of the discipline in the country. The promotion of research in Peru has spurred the growth of neurogenetics research, although limitations in infrastructure, technology, and education remain a challenge for the further growth of research in this field...
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Humanos , Genética , Pesquisa Translacional Biomédica , NeurologiaRESUMO
La Homocistinuria, es un desorden metabólico autosómico recesivo, cuya forma clásica es causada por deficiencia de cistationina β-sintasa, debido a mutaciones en el gen CBS (Cr 21q22.3). Se describe el caso de un varón de 17 años con hipopigmentación de piel y faneras, retraso psicomotor moderado, hábito marfanoide, miopía severa, subluxación del cristalino bilateral, que además presentó eventos psicóticos y una hemiparesia izquierda secundaria a un infarto lacunar. La determinación de homocisteína en plasma se encontró elevada (>9,9mg/dl), así como niveles altos de nitroprusiato de sodio en orina (4+) que confirmaron el diagnóstico clínico de homocistinuria. La homocistinuria clásica genera múltiples complicaciones a nivel dérmico, oftalmológico, cognitivo, osteoarticular y psiquiátrico; que podrían evitarse con un diagnóstico y tratamiento oportuno a través del tamizaje neonatal, aún no disponible en la mayoría de centros asistenciales en el Perú...
Homocystinuria is an autosomal-recessive metabolic disorder whose classical phenotype is caused by a deficiency of cystathionine β-synthase, due to mutations within the CBS gene (Cr21q22.3). Herein we report a 17 year old man with hypopigmented skin and hair, mental retardation, marfanoid habitus, severe myopia, bilateral lens subluxation, psychotic episodes, and left-sided hemiparesis secondary to a lacunar brain infarction. Laboratory tests showed increased levels of homocysteine (>9.9mg/dl) in plasma and high levels of urinary sodium nitroprusside (4+), consistent with the clinical diagnosis of classical homocystinuria. This systemic disorder includes dermal, ophthalmic, cognitive, osteoarticular and psychiatric alterations, all of which could be potentially prevented with early diagnosis and therapy as part of newborn screening, which is still unavailable in Peru...