Genetic origin of a large family with a novel PSEN1 mutation (Ile416Thr). Issue 5 (8th February 2019)

• Record Type: Journal Article
• Authors: Ramirez Aguilar, Laura; Acosta‐Uribe, Juliana; Giraldo, Margarita M.; Moreno, Sonia; Baena, Ana; Alzate, Diana; Cuastumal, Rosario; Aguillón, David; Madrigal, Lucía; Saldarriaga, Amanda; Navarro, Alexander; Garcia, Gloria P.; Aguirre‐Acevedo, Daniel C.; Geier, Ethan G.; Cochran, J. Nicholas; Quiroz, Yakeel T.; Myers, Richard M.; Yokoyama, Jennifer S.; Kosik, Kenneth S.; Lopera, Francisco
• Is Part Of: Alzheimer's & dementia. Volume 15:Issue 5(2019)
• Page Start: 709
• Page End: 719
• Publication Date: 2019-02-08
• Subjects: Autosomal dominant Alzheimer's disease -- Presenilin 1 -- Admixture in Latin America -- Genetic Bottleneck -- Phenotype genotype correlation -- Founder effect -- Genetic drift; Alzheimer's disease -- Periodicals; Alzheimer Disease -- Periodicals; Dementia -- Periodicals; Démence; Maladie d'Alzheimer; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.83
• DOI: 10.1016/j.jalz.2018.12.010
• Languages: English
• ISSNs: 1552-5260

Abstract

Abstract: Introduction: A small percentage of Alzheimer's disease (AD) cases are caused by genetic mutations with autosomal dominant inheritance. We report a family with a novel variant in PSEN1. Methods: We performed clinical and genetic evaluation of 93 related individuals from a Colombian admixed population. 31 individuals had whole‐genome sequencing. Results: Genetic analysis revealed a missense variant in PSEN1 (NM_000021.3: c.1247T>C p.Ile416Thr), which originated on an African haplotype and segregated with AD logarithm of the odds score of 6. Their clinical phenotype is similar to sporadic AD except for earlier age at onset: the mean age at onset for mild cognitive impairment was 47.6 years (standard deviation 5.83) and for dementia 51.6 years (standard deviation 5.03). Discussion: Ile416Thr is a novel pathogenic variant that causes AD in the sixth decade of life. The history of the region that included slave importation and admixtures within a confined geographic locale represents a "mini‐population bottleneck" and subsequent emergence of a rare dominant mutation.