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1.
medRxiv ; 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38645114

RESUMO

Introduction: Plasma phosphorylated threonine-181 of Tau and amyloid beta are biomarkers for differential diagnosis and preclinical detection of Alzheimer disease (AD). Given differences in AD risk across diverse populations, generalizability of existing biomarker data is not assured. Methods: In 2,086 individuals of diverse genetic ancestries (African American, Caribbean Hispanic, and Peruvians) we measured plasma pTau-181 and Aß42/Aß40. Differences in biomarkers between cohorts and clinical diagnosis groups and the potential discriminative performance of the two biomarkers were assessed. Results: pTau-181 and Aß42/Aß40 were consistent across cohorts. Higher levels of pTau181 were associated with AD while Aß42/Aß40 had minimal differences. Correspondingly, pTau-181 had greater predictive value than Aß42/Aß40, however, the area under the curve differed between cohorts. Discussion: pTau-181 as a plasma biomarker for clinical AD is generalizable across genetic ancestries, but predictive value may differ. Combining genomic and biomarker data from diverse individuals will increase understanding of genetic risk and refine clinical diagnoses.

2.
Stem Cell Res ; 76: 103364, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38422817

RESUMO

The ATP-binding cassette, subfamily A (ABC1), member 7 (ABCA7) gene is associated with Alzheimer's disease (AD) risk in populations of African, Asian, and European ancestry1-5. Numerous ABCA7 mutations contributing to risk have been identified, including a 44 base pair deletion (rs142076058) specific to individuals of African ancestry and predicted to cause a frameshift mutation (p.Arg578Alafs) (Cukier et al., 2016). The UMi043-A human induced pluripotent stem cell line was derived from an African American individual with AD who is heterozygous for this deletion and is a resource to further investigate ABCA7 and how this African-specific deletion may influence disease pathology.


Assuntos
Doença de Alzheimer , Linhagem Celular , Células-Tronco Pluripotentes Induzidas , Humanos , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Negro ou Afro-Americano/genética , Células-Tronco Pluripotentes Induzidas/citologia , Mutação
3.
J Alzheimers Dis ; 97(4): 1621-1627, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38306029

RESUMO

The objective of this study was to investigate attitudes toward brain donation and perceptions of medical research that influence brain donation among African Americans. Cross-sectional surveys were administered to African American community members (n = 227). Findings indicate that only 27% of respondents were willing to donate their brain. As medical mistrust was not found to be a significant barrier to research participation, there may be opportunity to increase brain donation by providing information about Alzheimer's disease and brain donation to potential donors and their families so that informed decisions about participating in research can be made.


Assuntos
Doença de Alzheimer , Negro ou Afro-Americano , Obtenção de Tecidos e Órgãos , Humanos , Atitude , Negro ou Afro-Americano/psicologia , Encéfalo , Estudos Transversais , Conhecimentos, Atitudes e Prática em Saúde , Inquéritos e Questionários , Seleção de Pacientes , Pesquisa Biomédica
4.
J Alzheimers Dis ; 98(1): 221-229, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38393909

RESUMO

Background: Cognitive and functional abilities in individuals with Alzheimer's disease (AD) pathology (ADP) are highly variable. Factors contributing to this variability are not well understood. Previous research indicates that higher educational attainment (EA) correlates with reduced cognitive impairments among those with ADP. While cognitive and functional impairments are correlated, they are distinguishable in their manifestations. Objective: To investigate whether levels of education are associated with functional impairments among those with ADP. Methods: This research involved 410 African American (AA) individuals (Institutional Review Boards 20070307, 01/27/2023) to ascertain whether EA correlates with functional resilience and if this effect varies between APOE ɛ4 carriers and non-carriers. Utilizing EA as a cognitive reserve proxy, CDR-FUNC as a functional difficulties measure, and blood pTau181 as an ADP proxy, the non-parametric Mann-Whitney U test assessed the relationship between EA and CDR-FUNC in individuals with advanced pTau181 levels. Results: The results showed that EA correlated with functional difficulties in AA individuals with high levels of pTau181, such that individuals with high EA are more likely to have better functional ability compared to those with lower EA (W = 730.5, p = 0.0007). Additionally, we found that the effect of high EA on functional resilience was stronger in ɛ4 non-carriers compared to ɛ4 carriers (W = 555.5, p = 0.022). Conclusion: This study extends the role of cognitive reserve and EA to functional performance showing that cognitive reserve influences the association between ADP burden and functional difficulties. Interestingly, this protective effect seems less pronounced in carriers of the strong genetic risk allele ɛ4.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Resiliência Psicológica , Humanos , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Disfunção Cognitiva/genética , Escolaridade
5.
J Community Health ; 49(3): 559-567, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38265538

RESUMO

African Americans continue to have worse health outcomes despite attempts to reduce health disparities. This is due, in part, to inadequate access to healthcare, but also to the health care and medical mistrust experienced by communities of color. Churches and worship centers have historically served as cultural centers of trusted resources for educational, financial, and health information within African American communities and a growing number of collaborations have developed between academic institutions and community/faith entities. Herein, we describe the infrastructure of a true and sustainable partnership developed with > 100 prominent faith leaders within the Piedmont Triad region of North Carolina for the purpose of developing or expanding existing health ministries within houses of worship, to improve health literacy and overall health long-term. The Triad Pastors Network is an asset-based partnership between the Maya Angelou Center for Health Equity at Wake Forest University School of Medicine and faith leaders in the Piedmont Triad region of North Carolina that was created under the guiding principles of community engagement to improve health equity and decrease health disparities experienced by African American communities. A partnership in which co-equality and shared governance are the core of the framework provides an effective means of achieving health-related goals in a productive and efficient manner. Faith-based partnerships are reliable approaches for improving the health literacy needed to address health disparities and inequities in communities of color.


Assuntos
Negro ou Afro-Americano , Promoção da Saúde , Humanos , Clero , North Carolina , Confiança , Letramento em Saúde , Desigualdades de Saúde
6.
J Gerontol Soc Work ; 67(2): 207-222, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37578097

RESUMO

Our analyses aimed to assess health status and critical needs of caregivers of persons with dementia (PWD) during the COVID-19 pandemic by gender. Between March 2021 and August 2021, respondents (n = 267) were recruited from an Alzheimer's disease (AD) listserv at an US academic center to complete a questionnaire to capture sociodemographic data, caregiving characteristics, health status, status of COVID-19 testing, and COVID-19 preventative practices during the pandemic. Women caregivers reported needing assistance with caregiving responsibilities, whereas men caregivers needed assistance with health and social resources. More men caregivers also reported psychological distress compared to women caregivers. Our findings indicated significant differences in the resources needed and psychological distress of women and men who cared for PWD during the COVID-19 pandemic. The development of recommendations and resources with both men and women caregivers in mind may be beneficial to support informal caregivers during emergency situations.


Assuntos
COVID-19 , Demência , Masculino , Humanos , Feminino , Cuidadores/psicologia , Demência/complicações , Demência/epidemiologia , Teste para COVID-19 , Fatores Sexuais , Pandemias , COVID-19/epidemiologia
7.
Health Educ Behav ; 51(1): 104-112, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37905517

RESUMO

The Black Men's Health Forum, a 6-week online health education intervention for African American men and accountability partners of African American men, was conducted to increase awareness of health issues that disproportionately affect African American men. In this article, we describe the intervention and report on the immediate benefits of the intervention, including changes in health knowledge and perception of research participation. Participants completed a pre-evaluation prior to participating in the forum and a post-evaluation after each session to capture data on sociodemographic information, medical history, health knowledge, and health behaviors. A total of 60 participants (30 African American men and 30 accountability partners) completed the forum. African American men had a mean age of 61.1 years while accountability partners had a mean age of 57.6 years. Overall health knowledge increased by 6.9 points for African American men and 2.8 points for accountability partners. Before the forum began, nine African American men reported ever participating in a research study. The proportion of African American men who reported that they would definitely participate in research in the next 12 months after participating in the forum increased by 40%. Through culturally tailored programming, the Black Men's Health Forum increased access to health information as well as African American male medical professionals and health researchers for African American men in the community. Exposure to health information resulted in significant increases in health knowledge and willingness to participate in health research among African American men.


Assuntos
Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Saúde do Homem , Participação do Paciente , Humanos , Masculino , Pessoa de Meia-Idade , Negro ou Afro-Americano , Comportamentos Relacionados com a Saúde
8.
Neurobiol Aging ; 133: 125-133, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37952397

RESUMO

There is a paucity of genetic studies of Alzheimer Disease (AD) in individuals of African Ancestry, despite evidence suggesting increased risk of AD in the African American (AA) population. We performed whole-genome sequencing (WGS) and multipoint linkage analyses in 51 multi-generational AA AD families ascertained through the Research in African American Alzheimer Disease Initiative (REAAADI) and the National Institute on Aging Late Onset Alzheimer's disease (NIA-LOAD) Family Based Study. Variants were prioritized on minor allele frequency (<0.01), functional potential of coding and noncoding variants, co-segregation with AD and presence in multi-ancestry ADSP release 3 WGS data. We identified a significant linkage signal on chromosome 5q35 (HLOD=3.3) driven by nine families. Haplotype segregation analysis in the family with highest LOD score identified a 3'UTR variant in INSYN2B with the most functional evidence. Four other linked AA families harbor within-family shared variants located in INSYN2B's promoter or enhancer regions. This AA family-based finding shows the importance of diversifying population-level genetic data to better understand the genetic determinants of AD on a global scale.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/genética , Doença de Alzheimer/epidemiologia , Escore Lod , Ligação Genética/genética , Haplótipos , Cromossomos , Predisposição Genética para Doença/genética
9.
medRxiv ; 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37693582

RESUMO

INTRODUCTION: Despite a two-fold increased risk, individuals of African ancestry have been significantly underrepresented in Alzheimer's Disease (AD) genomics efforts. METHODS: GWAS of 2,903 AD cases and 6,265 cognitive controls of African ancestry. Within-dataset results were meta-analyzed, followed by gene-based and pathway analyses, and analysis of RNAseq and whole-genome sequencing data. RESULTS: A novel AD risk locus was identified in MPDZ on chromosome 9p23 (rs141610415, MAF=.002, P =3.68×10 -9 ). Two additional novel common and nine novel rare loci approached genome-wide significance at P <9×10 -7 . Comparison of association and LD patterns between datasets with higher and lower degrees of African ancestry showed differential association patterns at chr12q23.2 ( ASCL1 ), suggesting that the association is modulated by regional origin of local African ancestry. DISCUSSION: Increased sample sizes and sample sets from Africa covering as much African genetic diversity as possible will be critical to identify additional disease-associated loci and improve deconvolution of local genetic ancestry effects.

10.
Int J Geriatr Psychiatry ; 38(9): e5992, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37655494

RESUMO

BACKGROUND: Alzheimer disease (AD) is more prevalent in African American (AA) and Hispanic White (HIW) compared to Non-Hispanic White (NHW) individuals. Similarly, neuropsychiatric symptoms (NPS) vary by population in AD. This is likely the result of both sociocultural and genetic ancestral differences. However, the impact of these NPS on AD in different groups is not well understood. METHODS: Self-declared AA, HIW, and NHW individuals were ascertained as part of ongoing AD genetics studies. Participants who scored higher than 0.5 on the Clinical Dementia Rating (CDR) Scale (CDR) were included. Group similarities and differences on Neuropsychiatric Inventory Questionnaire (NPI-Q) outcomes (NPI-Q total score, NPI-Q items) were evaluated using univariate ANOVAs and post hoc comparisons after controlling for sex and CDR stage. RESULTS: Our sample consisted of 498 participants (26% AA; 30% HIW; 44% NHW). Overall, NPI-Q total scores differed significantly between our groups, with HIW having the highest NPI-Q total scores, and by AD stage as measured by CDR. We found no significant difference in NPI-Q total score by sex. There were six NPI-Q items with comparable prevalence in all groups and six items that significantly differed between the groups (Anxiety, Apathy, Depression, Disinhibition, Elation, and Irritability). Further, within the HIW group, differences were found between Puerto Rican and Cuban American Hispanics across several NPI-Q items. Finally, Six NPI-Q items were more prevalent in the later stages of AD including Agitation, Appetite, Hallucinations, Irritability, Motor Disturbance, and Nighttime Behavior. CONCLUSIONS: We identified differences in NPS among HIW, AA, and NHW individuals. Most striking was the high burden of NPS in HIW, particularly for mood and anxiety symptoms. We suggest that NPS differences may represent the impact of sociocultural influences on symptom presentation as well as potential genetic factors rooted in ancestral background. Given the complex relationship between AD and NPS it is crucial to discern the presence of NPS to ensure appropriate interventions.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/genética , Doença de Alzheimer/psicologia , Ansiedade , Disfunção Cognitiva/genética , Disfunção Cognitiva/psicologia , Etnicidade , Hispânico ou Latino , Negro ou Afro-Americano , Brancos
11.
Neurology ; 101(7 Suppl 1): S47-S58, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37580153

RESUMO

The national mandate to improve health equity in the United Sates is advancing. Racial and ethnic disparities in various aspects of health care have been clearly delineated, and sources of such disparities have been identified. However, implementing solution-focused interventions to eradicate such disparities, thereby achieving health equity in all US communities, has remained a daunting challenge, and no area more so, than with neurologic diseases. To assure success with bridging prominent disparities in neurologic outcomes, the pipeline of neurologic disparities researchers needs to be broadened, numbers of mid-career and senior disparities scientists sustained, partnerships with community stakeholders enhanced, incentivization of academic organizations pursued, education of all neurologic researchers conducted, and exemplary training of funding agency staff prioritized. To improve the current state of neurologic disparities, the National Institute of Neurological Disorders and Stroke assembled a working group of its advisory council. (2020-2022) to examine the state of health disparity training and research. Through consensus building, we present identified gaps and recommendations to the current state of underrepresented groups in medicine in health disparity research and its training and curricula in the United States.


Assuntos
National Institute of Neurological Disorders and Stroke (USA) , Doenças do Sistema Nervoso , Humanos , Estados Unidos , Atenção à Saúde , Grupos Raciais , Currículo , Doenças do Sistema Nervoso/terapia , Disparidades em Assistência à Saúde
12.
Artigo em Inglês | MEDLINE | ID: mdl-37580437

RESUMO

OBJECTIVES: The COVID-19 pandemic has revealed significant differences in COVID-19 vaccination rates, with African Americans reporting lower rates compared to other racial and ethnic groups. The purpose of these analyses was to assess whether COVID-19 vaccination status differed according to age in a sample of 1,240 African American adult congregants of faith-based organizations ages 18 years or older, and to examine whether this association was moderated by gender. DESIGN: We developed and administered a 75-item cross-sectional survey, the Triad Pastor's Network COVID-19 and COVID-19 Vaccination survey, to assess experiences and perceptions regarding the COVID-19 virus and vaccines. We assessed the association between age and having received > 1 dose of a COVID-19 vaccine using unadjusted and multivariable binary logistic regression models, and the interaction of age and gender with COVID-19 vaccination status in a multivariable model. RESULTS: Approximately 86% of participants reported having received ≥ 1 dose of a COVID-19 vaccine. The mean age (standard deviation) of the sample was 51.33 (16.62) years, and 70.9% of the sample was comprised of women. The age by gender interaction term in the multivariable model was significant (p = 0.005), prompting additional analyses stratified by gender. In women, increased age was significantly associated with higher odds of COVID-19 vaccination (odds ratio = 1.09; 95% Confidence Interval 1.06, 1.11; p < 0.001). In men, the association was not significant (p = 0.44). CONCLUSIONS: Older age was positively associated with COVID-19 vaccination in African American women, but not African American men, which may inform strategies to increase vaccination rates.

13.
medRxiv ; 2023 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-37461667

RESUMO

Cognitive and functional abilities in individuals with Alzheimer disease (AD) pathology (ADP) show greater than expected variability. While most individuals show substantial impairments in these abilities, a considerable number show little or no impairments. Factors contributing to this variability are not well understood. For instance, multiple studies have shown that higher levels of education are associated with reduced cognitive impairments among those with ADP. However, it remains unclear whether higher levels of education are associated with functional impairments among those with ADP. We studied 410 AA individuals with advanced levels of pTau181 (a biomarker for ADP; individuals as those having log 10 (pTau181) level greater than one standard deviation above the mean) to determine whether EA (categorized as low EA for individuals with ≤ 8 years of education and high EA for those with >8 years) promotes functional resilience and whether this effect varies between APOE ε4 carriers and non-carriers. We used the four non-memory components of the Clinical Dementia Rating (CDR) to create a composite score (CDR-FUNC) to evaluate functional difficulties (scored from 0=no impairment to 12=severe). We employed the non-parametric Mann-Whitney U test to assess the relationship between EA and CDR-FUNC in advanced levels of pTau181 individuals. The results showed that EA promotes resilience to functional problems in AA individuals with advanced levels of pTau181, such that individuals with high EA are more likely to have better functional ability compared to those with lower EA (W=730.5, p=0.0007). Additionally, we found that the effect of high EA on functional resilience was stronger in ε4 non-carriers compared to ε4 carriers (W=555.5, p=0.022). This study extends the role of cognitive reserve and EA to functional performance showing that cognitive reserve influences the association between ADP burden and functional difficulties. Interestingly, this protective effect seems less pronounced in carriers of the strong genetic risk allele ε4. The results highlight the intricate interplay of genetic and non-genetic factors in AD progression, suggesting a need for more personalized strategies to manage functional decline in AD.

14.
Artigo em Inglês | MEDLINE | ID: mdl-37273163

RESUMO

BACKGROUND: Mistrust of the government and medical establishments are prominent reasons for vaccine hesitancy among African Americans (AAs). As COVID-19 research evolves in real time with some uncertainties remaining, AA communities may be less trusting of public health agencies. The purpose of these analyses was to assess the association between trust in public health agencies that recommend the COVID-19 vaccination and COVID-19 vaccination status among AAs in North Carolina. METHODS: A 75-item cross-sectional survey, the Triad Pastors Network COVID-19 and COVID-19 Vaccination survey, was developed and administered to African Americans in North Carolina. Multivariable logistic regression was used to examine the association between levels of trust in public health agencies who recommend the COVID-19 vaccine and COVID-19 vaccination status among AAs. RESULTS: Of the 1157 AAs included in these analyses, approximately 14% of AAs had not received the COVID-19 vaccine. These findings indicated that lower levels of trust in public health agencies significantly decreased the odds of getting the COVID-19 vaccination compared to those with higher levels of trust among AAs. The most trusted source for information on COVID-19 included federal agencies among all respondents. Among the vaccinated, primary care physicians were another trusted source of information. Pastors were another trusted source for those willing to be vaccinated. CONCLUSIONS: Despite the majority of the respondents in this sample receiving the COVID-19 vaccine, subgroups of AAs remain unvaccinated. Federal agencies have a high level of trust among AA adults; however, innovative approaches are needed to reach AAs who remain unvaccinated.

15.
Alzheimers Dement ; 19(12): 5437-5446, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37212603

RESUMO

INTRODUCTION: The underrepresentation of African Americans (AAs) in Alzheimer's disease (AD) research may limit potential benefits from translational applications. This article describes an approach to recruit AA families into an AD genomic study and characteristics of seeds (family connectors) used to overcome recruitment barriers of AA families into AD research. METHODS: A four-step outreach and snowball sampling approach relying on family connectors was used to recruit AA families. Descriptive statistics of a profile survey were gathered to understand the demographic and health characteristics of family connectors. RESULTS: Twenty-five AA families (117 participants) were enrolled in the study via family connectors. Most family connectors self-identified as female (88%), were 60 years of age or older (76%), and attained post-secondary education (77%). DISCUSSION: Community-engaged strategies were essential to recruit AA families. Relationships between study coordinators and family connectors build trust early in the research process among AA families. HIGHLIGHTS: Community events were most effective for recruiting African American families. Family connectors were primarily female, in good health, and highly educated. Systematic efforts by researchers are necessary to "sell" a study to participants.


Assuntos
Doença de Alzheimer , Feminino , Humanos , Doença de Alzheimer/genética , Negro ou Afro-Americano , Genômica , Masculino , Pessoa de Meia-Idade
16.
Alzheimers Dement ; 19(7): 3119-3128, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36724324

RESUMO

INTRODUCTION: Discrimination negatively impacts health and may contribute to racial/ethnic disparities in dementia risk. METHODS: Experiences of lifetime and everyday discrimination were assessed among 6509 Multi-Ethnic Study of Atherosclerosis (MESA) participants. We assessed the association of discrimination with incidence of dementia including adjustment for important risk factors, cohort attrition, and we assessed for effect modification by race/ethnicity. RESULTS: Prevalence of any lifetime discrimination in MESA was 42%, highest among Black adults (72%). Over a median 15.7 years of follow-up, there were 466 incident cases of dementia. Lifetime discrimination, but not everyday discrimination, was associated with incident dementia (Wald p = 0.03). Individuals reporting lifetime discrimination in ≥2 domains (compared to none) had greater risk for dementia (hazard ratio: 1.40; 95%: 1.08, 1.82) after adjustment for sociodemographic, clinical, and behavioral risk factors. Associations did not differ by race/ethnicity. CONCLUSIONS: These findings demonstrate an association of greater experiences of lifetime discrimination with incident dementia.


Assuntos
Demência , Etnicidade , Racismo , Adulto , Humanos , População Negra , Demência/epidemiologia , Demência/etnologia , Demência/etiologia , Demência/psicologia , Fatores de Risco , Autorrelato , Racismo/etnologia , Racismo/psicologia
17.
J Natl Med Assoc ; 115(1): 26-37, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36599744

RESUMO

Objective To delineate the etiology, symptomatology, and treatment of sickle cell intrahepatic cholestasis (SCIC). Sickle cell disease (SCD) is the most frequently inherited hematologic disease, and SCIC is one rare and often fatal complication and comorbid disease. The literature contains only a small number of case reports involving SCIC and hence limited guidance can be obtained. Methods We reviewed the scientific literature to evaluate the science of SCIC to determine if there were consistencies in presentation, evaluation, treatment, and clinical outcomes. Results We reviewed 6 case reports and a limited number of clinical papers on SCIC. We reported consistencies in clinical presentation and treatment outcomes among cases as well as serological and hematological finding. Conclusions While there is some consistency in the symptom presentation of individuals with SCIC, reliable evaluation and clinical procedures were not demonstrated in what we reviewed. Further research is needed to delineate the attributes of this complicated disease that occurs within SCD.


Assuntos
Anemia Falciforme , Colestase Intra-Hepática , Humanos , Colestase Intra-Hepática/diagnóstico , Colestase Intra-Hepática/etiologia , Colestase Intra-Hepática/terapia , Anemia Falciforme/complicações , Anemia Falciforme/diagnóstico , Anemia Falciforme/terapia , Eritrócitos Anormais
18.
Alzheimers Dement ; 19(6): 2538-2548, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36539198

RESUMO

BACKGROUND: This study used admixture mapping to prioritize the genetic regions associated with Alzheimer's disease (AD) in African American (AA) individuals, followed by ancestry-aware regression analysis to fine-map the prioritized regions. METHODS: We analyzed 10,271 individuals from 17 different AA datasets. We performed admixture mapping and meta-analyzed the results. We then used regression analysis, adjusting for local ancestry main effects and interactions with genotype, to refine the regions identified from admixture mapping. Finally, we leveraged in silico annotation and differential gene expression data to prioritize AD-related variants and genes. RESULTS: Admixture mapping identified two genome-wide significant loci on chromosomes 17p13.2 (p = 2.2 × 10-5 ) and 18q21.33 (p = 1.2 × 10-5 ). Our fine mapping of the chromosome 17p13.2 and 18q21.33 regions revealed several interesting genes such as the MINK1, KIF1C, and BCL2. DISCUSSION: Our ancestry-aware regression approach showed that AA individuals have a lower risk of AD if they inherited African ancestry admixture block at the 17p13.2 locus. HIGHLIGHTS: We identified two genome-wide significant admixture mapping signals: on chromosomes 17p13.2 and 18q21.33, which are novel in African American (AA) populations. Our ancestry-aware regression approach showed that AA individuals have a lower risk of Alzheimer's disease (AD) if they inherited African ancestry admixture block at the 17p13.2 locus. We found that the overall proportion of African ancestry does not differ between the cases and controls that suggest African genetic ancestry alone is not likely to explain the AD prevalence difference between AA and non-Hispanic White populations.


Assuntos
Doença de Alzheimer , Predisposição Genética para Doença , Humanos , Predisposição Genética para Doença/genética , Negro ou Afro-Americano/genética , Doença de Alzheimer/genética , Mapeamento Cromossômico/métodos , Genótipo , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único/genética , Cinesinas/genética , Proteínas Serina-Treonina Quinases/genética
19.
PLoS Genet ; 18(7): e1009977, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35788729

RESUMO

African descent populations have a lower Alzheimer disease risk from ApoE ε4 compared to other populations. Ancestry analysis showed that the difference in risk between African and European populations lies in the ancestral genomic background surrounding the ApoE locus (local ancestry). Identifying the mechanism(s) of this protection could lead to greater insight into the etiology of Alzheimer disease and more personalized therapeutic intervention. Our objective is to follow up the local ancestry finding and identify the genetic variants that drive this risk difference and result in a lower risk for developing Alzheimer disease in African ancestry populations. We performed association analyses using a logistic regression model with the ApoE ε4 allele as an interaction term and adjusted for genome-wide ancestry, age, and sex. Discovery analysis included imputed SNP data of 1,850 Alzheimer disease and 4,331 cognitively intact African American individuals. We performed replication analyses on 63 whole genome sequenced Alzheimer disease and 648 cognitively intact Ibadan individuals. Additionally, we reproduced results using whole-genome sequencing of 273 Alzheimer disease and 275 cognitively intact admixed Puerto Rican individuals. A further comparison was done with SNP imputation from an additional 8,463 Alzheimer disease and 11,365 cognitively intact non-Hispanic White individuals. We identified a significant interaction between the ApoE ε4 allele and the SNP rs10423769_A allele, (ß = -0.54,SE = 0.12,p-value = 7.50x10-6) in the discovery data set, and replicated this finding in Ibadan (ß = -1.32,SE = 0.52,p-value = 1.15x10-2) and Puerto Rican (ß = -1.27,SE = 0.64,p-value = 4.91x10-2) individuals. The non-Hispanic Whites analyses showed an interaction trending in the "protective" direction but failing to pass a 0.05 significance threshold (ß = -1.51,SE = 0.84,p-value = 7.26x10-2). The presence of the rs10423769_A allele reduces the odds ratio for Alzheimer disease risk from 7.2 for ApoE ε4/ε4 carriers lacking the A allele to 2.1 for ApoE ε4/ε4 carriers with at least one A allele. This locus is located approximately 2 mB upstream of the ApoE locus, in a large cluster of pregnancy specific beta-1 glycoproteins on chromosome 19 and lies within a long noncoding RNA, ENSG00000282943. This study identified a new African-ancestry specific locus that reduces the risk effect of ApoE ε4 for developing Alzheimer disease. The mechanism of the interaction with ApoEε4 is not known but suggests a novel mechanism for reducing the risk for ε4 carriers opening the possibility for potential ancestry-specific therapeutic intervention.


Assuntos
Doença de Alzheimer , Alelos , Doença de Alzheimer/genética , Apolipoproteína E4/genética , Apolipoproteínas E/genética , Genótipo , Humanos , Nigéria , Fatores de Risco
20.
Hum Mol Genet ; 31(17): 2876-2886, 2022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-35383839

RESUMO

Most Alzheimer's disease (AD)-associated genetic variants do not change protein coding sequence and thus likely exert their effects through regulatory mechanisms. RNA editing, the post-transcriptional modification of RNA bases, is a regulatory feature that is altered in AD patients that differs across ancestral backgrounds. Editing QTLs (edQTLs) are DNA variants that influence the level of RNA editing at a specific site. To study the relationship of DNA variants genome-wide, and particularly in AD-associated loci, with RNA editing, we performed edQTL analyses in self-reported individuals of African American (AF) or White (EU) race with corresponding global genetic ancestry averaging 82.2% African ancestry (AF) and 96.8% European global ancestry (EU) in the two groups, respectively. We used whole-genome genotyping array and RNA sequencing data from peripheral blood of 216 AD cases and 212 age-matched, cognitively intact controls. We identified 2144 edQTLs in AF and 3579 in EU, of which 1236 were found in both groups. Among these, edQTLs in linkage disequilibrium (r2 > 0.5) with AD-associated genetic variants in the SORL1, SPI1 and HLA-DRB1 loci were associated with sites that were differentially edited between AD cases and controls. While there is some shared RNA editing regulatory architecture, most edQTLs had distinct effects on the rate of RNA editing in different ancestral populations suggesting a complex architecture of RNA editing regulation. Altered RNA editing may be one possible mechanism for the functional effect of AD-associated variants and may contribute to observed differences in the genetic etiology of AD between ancestries.


Assuntos
Doença de Alzheimer , Edição de RNA , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , População Negra , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Proteínas Relacionadas a Receptor de LDL/metabolismo , Desequilíbrio de Ligação , Proteínas de Membrana Transportadoras/genética , Locos de Características Quantitativas/genética , Edição de RNA/genética
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