👤 Richard E Reitz

Obesity and Alzheimer’s disease (AD) are epidemiologically associated. The locus coeruleus (LC)—the brain’s primary and most significant source of norepinephrine—is one of the earliest sites of neurodegeneration in AD. The LC participates in feeding behavior through connections with the hypothalamus. The cellular composition of the LC has been characterized at single-cell resolution. However, the constituent cellular signatures of genes related to energy homeostasis—such as the melanocortin pathway genes—in the LC are unclear. We performed single-nucleus RNA sequencing and spatial transcriptomics (Visium) in the human LC, and HiPlex RNAscope in the LC of mice. The melanocortin pathway gene The online version contains supplementary material available at 10.1186/s40478-026-02287-x. Show less

Epidemiological studies have consistently shown that chronic kidney disease is associated with increased Alzheimer disease risk. However, the underlying genetic architecture connecting these two conditions remains largely unexplored beyond genome-wide correlation analyses. Here, we conducted the first comprehensive, multi-ancestry, large-scale genetic investigation to identify shared genetic components between kidney function and Alzheimer disease. We leveraged large-scale genome-wide association study summary statistics for estimated glomerular filtration rate (N≈1.5 million European, N≈145,000 African ancestry) and late-onset Alzheimer disease (N=63,926 and N=398,058 in two European cohorts; N=9,168 in African ancestry) corrected for competing risk bias. We deployed a novel analytical framework integrating linkage disequilibrium score regression and polygenic risk score analysis, local analysis of [co]variant association, conjunctional false discovery rate analysis with Bayesian colocalization and fine-mapping, and bidirectional cis-Mendelian randomization to identify vertical pleiotropy. Despite the absence of genome-wide genetic correlation (r Show less

Late-onset Alzheimer's disease (LOAD) is highly heritable; however, its estimated incidence across populations remains unclear. We computed family-based heritability leveraging Alzheimer's Disease Sequencing Project pedigrees from non-Hispanic White (404 pedigrees), non-Hispanic Black (13 pedigrees), Dominican (100 pedigrees), and Dutch isolate (10 pedigrees), with four models incorporating age, sex, apolipoproten E epsilon4 (APOE ε4), and contributing study using two methods. Heritability estimates varied by method, model, and study populations. Statistical Analysis for Genetic Epidemiology (S.A.G.E.) estimates were highest for Dutch isolate (78.3%), followed by non-Hispanic Blacks (39.1%), Dominicans (31.7%), and non-Hispanic Whites (29.1%), adjusted for age and sex. APOE adjustment reduced estimates (4.9% on average), while study adjustment primarily affected groups that included multiple studies. Sequential Oligogenic Linkage Analysis Routines (SOLAR-Eclipse) estimates were higher (45.2% to 80.2%) than S.A.G.E. (20.4% to 80.9%) but behaved in parallel, except for the Dutch isolate. LOAD heritability estimates are dependent on study population and may reflect or indicate differences in LOAD risk by population. Show less

BackgroundEducation promotes cognitive reserve (CR), potentially buffering Alzheimer's disease pathology (ADP). However, the education-CR relationship may differ by population and genetic background.ObjectiveTo examine education, Show less

Fibroblast growth factor 21 (FGF21) analogs are in development for metabolic dysfunction-associated steatotic liver disease (MASLD), but their impact on problematic alcohol use (PAU), alcohol use disorder, binge drinking, and alcohol-related liver disease (ALD) is unknown. We leveraged genome-wide association study data from the UK Biobank, FinnGen, Million Veterans Program, and GenomALC for PAU, alcohol use disorder, binge drinking, weekly drinks, and ALD. Our four-tier evaluation included: (1) multivariable Mendelian randomization (MR) and mediation with circulating FGF21 levels; (2) comparative MR of MASLD and ALD targets (PNPLA3, TM6SF2, HSD17B13) using liver fat and expression instruments; (3) receptor-focused MR of β-Klotho (KLB) and FGFR1/2/3 incorporating brain-region expression; and (4) a phenome-wide MR across 1,022 traits to assess safety. Genetically higher FGF21 protein levels were associated with lower PAU (β = -0.097, 95% CI -0.135 to -0.059, p = 6.13 × 10 Human genetic evidence indicates that FGF21 analogs mitigate hazardous drinking and ALD via both behavioral and metabolic pathways. These findings distinguish FGF21 from other MASLD targets and highlight its potential for precision treatment of alcohol-related disorders. This study leverages human genetic evidence to validate FGF21 - a liver-derived hormone currently in clinical trials for fatty liver disease - as a dual-action therapeutic that both curbs harmful drinking behaviors and protects against alcohol-related liver injury, addressing a critical therapeutic gap with limited existing pharmacotherapies. The results are important for clinicians and researchers seeking precision medicine strategies for alcohol use disorder and liver disease, as well as for patients who currently face limited treatment options. By pinpointing FGF21's behavioral and metabolic pathways and demonstrating a favorable safety profile, our findings support the repurposing of FGF21 analogs in clinical trials of alcohol use disorder and alcohol-related liver disease and suggest that genetic stratification could optimize patient selection for therapy. While these conclusions rely on European-ancestry genetic data and Mendelian randomization assumptions, they help inform future clinical studies, biomarker development, and policy efforts aimed at expanding treatment options for alcohol-related conditions. Show less

Pharmacological modulation of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) through dual GIP/GLP-1 receptor agonists, commonly used for diabetes and obesity, shows promise in reducing alcohol consumption. We applied drug-target Mendelian randomization (MR) using genetic variation at these loci to assess their long-term effects on problematic alcohol use (PAU), binge drinking, alcohol misuse classifications, liver health, and other substance use behaviors. Genetic proxies for lowered BMI, modeling the appetite-suppressing and weight-reducing effects of variants in both the GIPR and GLP1R loci ("GIPR/GLP1R"), were linked with reduced binge drinking in the primary (β = -0.44, 95% CI [-0.72, -0.15], P = 2.42 × 10 Show less

The genetic component of early-onset Alzheimer disease (EOAD), accounting for ~10% of all Alzheimer's disease (AD) cases, is largely unexplained. Recent studies suggest that EOAD may be enriched for variants acting in the lipid pathway. The current study examines the shared genetic heritability between EOAD and the lipid pathway using genome-wide multi-trait genetic covariance analyses. Summary statistics were obtained from the GWAS meta-analyses of EOAD by the Alzheimer's Disease Genetics Consortium (n=19,668) and five blood lipid traits by the Global Lipids Genetics Consortium (n=1,320,016). The significant results were compared between the EOAD and lipids GWAS and genetic covariance analyses were performed via SUPERGNOVA. Genes in linkage disequilibrium (LD) with top EOAD hits in identified regions of covariance with lipid traits were scored and ranked for causality by combining evidence from gene-based analysis, AD-risk scores incorporating transcriptomic and proteomic evidence, eQTL data, eQTL colocalization analyses, DNA methylation data, and single-cell RNA sequencing analyses. Direct comparison of GWAS results showed 5 loci overlapping between EOAD and at least one lipid trait harboring APOE, TREM2, MS4A4E, LILRA5, and LRRC25. Local genetic covariance analyses identified 3 regions of covariance between EOAD and at least one lipid trait. Gene prioritization nominated 3 likely causative genes at these loci: ANKDD1B, CUZD1, and MS4A64.The current study identified genetic covariance between EOAD and lipids, providing further evidence of shared genetic architecture and mechanistic pathways between the two traits. Show less

Less than 10% of early-onset Alzheimer's disease (EOAD) is explained by known mutations. We conducted genetic linkage analysis of 68 well-phenotyped Caribbean Hispanic families without clear inheritance patterns or mutations in We identified 16 (logarithm of odds > 3.6) linked regions, including eight novel loci for EOAD (2p15, 5q14.1, 11p15.1, 13q21.22, 13q33.1, 16p12.1, 20p12.1, and 20q11.21) and eight regions previously associated with late-onset Alzheimer's disease. The strongest signal was observed at 16p12.1 (25 cM, 33 Mb; heterogeneity logarithm of odds = 5.3), ∼3 Mb upstream of the ceroid lipofuscinosis 3 ( This study supports the notion that the genetic architectures of unexplained EOAD and late-onset AD overlap partially, but not fully. Show less

In a whole-exome sequencing study of multiplex Alzheimer's disease (AD) families, we investigated three neuronal ceroid lipofuscinosis genes that have been linked to retromer, an intracellular trafficking pathway associated with AD: ceroid lipofuscinosis 3 (CLN3), ceroid lipofuscinosis 5 (CLN5), and cathepsin D (CTSD). We identified a missense variant in CLN5 c.A959G (p.Asn320Ser) that segregated with AD. We find that this variant causes glycosylation defects in the expressed protein, which causes it to be retained in the endoplasmic reticulum with reduced delivery to the endolysosomal compartment, CLN5's normal cellular location. The AD-associated CLN5 variant is shown here to reduce the normal processing of cathepsin D and to decrease levels of full-length amyloid precursor protein (APP), suggestive of a defect in retromer-dependent trafficking. Show less

Whereas epidemiological studies show that levels of low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) predict incident cardiovascular disease (CVD), there is limited evidence relating lipoprotein subfractions and composite measures of subfractions to risk for CVD in prospective cohort studies. We tested whether combinations of lipoprotein subfractions independently predict CVD in a prospective cohort of 4594 initially healthy men and women (the Malmö Diet and Cancer Study, mean follow-up 12.2 years, 377 incident cardiovascular events). Plasma lipoproteins and lipoprotein subfractions were measured at baseline with a novel high-resolution ion mobility technique. Principal component analysis (PCA) of subfraction concentrations identified 3 major independent (ie, zero correlation) components of CVD risk, one representing LDL-associated risk, a second representing HDL-associated protection, and the third representing a pattern of decreased large HDL, increased small/medium LDL, and increased triglycerides. The last corresponds to the previously described "atherogenic lipoprotein phenotype." Several genes that may underlie this phenotype-CETP, LIPC, GALNT2, MLXIPL, APOA1/A5, LPL-are suggested by SNPs associated with the combination of small/medium LDL and large HDL. PCA on lipoprotein subfractions yielded three independent components of CVD risk. Genetic analyses suggest these components represent independent mechanistic pathways for development of CVD. Show less