RESUMEN
Frontotemporal dementia (FTD) is the second most common cause of early-onset dementia after Alzheimer disease (AD). Efforts in the field mainly focus on familial forms of disease (fFTDs), while studies of the genetic etiology of sporadic FTD (sFTD) have been less common. In the current work, we analyzed 4,685 sFTD cases and 15,308 controls looking for common genetic determinants for sFTD. We found a cluster of variants at the MAPT (rs199443; p = 2.5 × 10-12, OR = 1.27) and APOE (rs6857; p = 1.31 × 10-12, OR = 1.27) loci and a candidate locus on chromosome 3 (rs1009966; p = 2.41 × 10-8, OR = 1.16) in the intergenic region between RPSA and MOBP, contributing to increased risk for sFTD through effects on expression and/or splicing in brain cortex of functionally relevant in-cis genes at the MAPT and RPSA-MOBP loci. The association with the MAPT (H1c clade) and RPSA-MOBP loci may suggest common genetic pleiotropy across FTD and progressive supranuclear palsy (PSP) (MAPT and RPSA-MOBP loci) and across FTD, AD, Parkinson disease (PD), and cortico-basal degeneration (CBD) (MAPT locus). Our data also suggest population specificity of the risk signals, with MAPT and APOE loci associations mainly driven by Central/Nordic and Mediterranean Europeans, respectively. This study lays the foundations for future work aimed at further characterizing population-specific features of potential FTD-discriminant APOE haplotype(s) and the functional involvement and contribution of the MAPT H1c haplotype and RPSA-MOBP loci to pathogenesis of sporadic forms of FTD in brain cortex.
Asunto(s)
Apolipoproteínas E , Demencia Frontotemporal , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Proteínas tau , Humanos , Demencia Frontotemporal/genética , Proteínas tau/genética , Apolipoproteínas E/genética , Masculino , Femenino , Anciano , Polimorfismo de Nucleótido Simple , Sitios Genéticos , Persona de Mediana Edad , Estudios de Casos y Controles , Proteínas de la MielinaRESUMEN
Introducción y desarrollo. La enfermedad de Alzheimer (EA), la causa más frecuente de demencia, es una enfermedad compleja en la que factores ambientales y genéticos interactúan para dar lugar al fenotipo final. Existen tres genes que se han asociado a formas preseniles autosómicas dominantes de la enfermedad: el gen que codifica para la proteína precursora del péptido beta-amiloide (APP) y los genes de las presenilinas (PSEN1 y PSEN2). Un cuarto gen, el gen de la apolipoproteína E (APOE), es el único gen mayor de susceptibilidad para las formas, tanto esporádicas como familiares, tardías, de EA. Aunque se han realizado miles de estudios genéticos, se conoce poco sobre la arquitectura genética de la EA. Aun así, en los últimos tres años ha habido un salto cualitativo extraordinario gracias a la utilización de las novedosas tecnologías de genotipado masivo, las cuales han permitido un análisis exhaustivo del genoma. Conclusión. Esta revisión resume el conocimiento actual de las causas genéticas relacionadas con la EA (AU)
Introduction and development. Alzheimers disease (AD), the leading cause of dementia, is a complex disorder in which genetic and environmental factors interact. Three genes the amyloid precursor protein (APP) and the presenilin 1 and 2 (PSEN1 and PSEN2) have been linked to atusosomal dominant forms of AD. Besides, a fourth gene the apolipoprotein E gene (APOE) seems to be the only major genetic factor related to late-onset sporadic and familial AD cases. Although more than a thousand studies have been performed to date, little is known about other genetic factors leading to this devastating dementia. Nevertheless, the last three years have witnessed a surge in genetic research of AD due to the implementation of novel technologies enabling large-scale genetic analyses. Conclusion. This review provides a summary of current knowledge about AD in the genetic field (AU)