Basic Science and Pathogenesis.

Background: We identified the missense variant Ser1038Cys (rs377155188) in the tetratricopeptide repeat domain 3 (TTC3) gene that segregate in a non-Hispanic white late onset Alzheimer disease (LOAD) family. This variant is predicted to be deleterious and extremely rare (MAF<0.01%).

Basic Science and Pathogenesis.

Background: In the US, African Americans (admixed with African and European) followed by Hispanics (admixed with Amerindian, African, and European) are the most affected groups compared to non-Hispanic Whites (NHW). While genetic diversity and admixture play crucial roles in disease risk, the ancestry-specific mechanisms remain poorly understood with most AD-related studies focusing on NHW. Despite the recent field efforts to include genetically admixed populations, there continues to be a lack of functional studies in AD across the different cell types in these populations.

Basic Science and Pathogenesis.

Background: Dysregulation of endolysosomal trafficking is a major pathogenic mechanism in Alzheimer's disease (AD). From the family of AD-linked endosomal pathway genes, SORL1 stands out as one of the highest risk factors. SORL1 encodes an endocytic sorting receptor that mediates endosomal trafficking and processing of key AD-associated molecules, including pathogenic forms of amyloid-β (e.

Basic Science and Pathogenesis.

Background: Genome-wide association studies (GWAS) in Alzheimer's disease (AD) are consistently discovering genetic variants linked to the risk of developing this neurodegenerative condition. However, the effect size of the shared associated loci varies across populations as well as each population can have unique associations. This phenomenon could be explained by ancestry-dependent changes in the genomic regulatory architecture (GRA) influencing the expression of these genes, similar to the effect of different local ancestry on the risk of AD in APOE4 carriers.

Ancestral Genomic Functional Differences in Oligodendroglia: Implications for Alzheimer's Disease.

Background: This study aims to elucidate ancestry-specific changes to the genomic regulatory architecture in induced pluripotent stem cell (iPSC)-derived oligodendroglia, focusing on their implications for Alzheimer's disease (AD). This work addresses the lack of diversity in previous iPSC studies by including ancestries that contribute to African American (European/African) and Hispanic/Latino populations (Amerindian/African/European).

Methods: We generated 12 iPSC lines-four African, four Amerindian, and four European- from both AD patients and non-cognitively impaired individuals, with varying genotypes ( and ).