1
|
Uddin MS, Hasana S, Hossain MF, Islam MS, Behl T, Perveen A, Hafeez A, Ashraf GM. Molecular Genetics of Early- and Late-Onset Alzheimer's Disease. Curr Gene Ther 2021; 21:43-52. [PMID: 33231156 DOI: 10.2174/1566523220666201123112822] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/17/2020] [Accepted: 10/19/2020] [Indexed: 11/22/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the elderly and this complex disorder is associated with environmental as well as genetic factors. Early-onset AD (EOAD) and late-onset AD (LOAD, more common) are major identified types of AD. The genetics of EOAD is extensively understood, with three gene variants such as APP, PSEN1, and PSEN2 leading to the disease. Some common alleles, including APOE, are effectively associated with LOAD identified, but the genetics of LOAD is not clear to date. It has been accounted that about 5-10% of EOAD patients can be explained through mutations in the three familiar genes of EOAD. The APOE ε4 allele augmented the severity of EOAD risk in carriers, and the APOE ε4 allele was considered as a hallmark of EOAD. A great number of EOAD patients, who are not genetically explained, indicate that it is not possible to identify disease-triggering genes yet. Although several genes have been identified by using the technology of next-generation sequencing in EOAD families, including SORL1, TYROBP, and NOTCH3. A number of TYROBP variants are identified through exome sequencing in EOAD patients and these TYROBP variants may increase the pathogenesis of EOAD. The existence of the ε4 allele is responsible for increasing the severity of EOAD. However, several ε4 allele carriers propose the presence of other LOAD genetic as well as environmental risk factors that are not identified yet. It is urgent to find out missing genetics of EOAD and LOAD etiology to discover new potential genetic facets which will assist in understanding the pathological mechanism of AD. These investigations should contribute to developing a new therapeutic candidate for alleviating, reversing and preventing AD. This article, based on current knowledge, represents the overview of the susceptible genes of EOAD, and LOAD. Next, we represent the probable molecular mechanism that might elucidate the genetic etiology of AD and highlight the role of massively parallel sequencing technologies for novel gene discoveries.
Collapse
Affiliation(s)
- Md Sahab Uddin
- Department of Pharmacy, Southeast University, Dhaka, Bangladesh
| | - Sharifa Hasana
- Department of Pharmacy, Southeast University, Dhaka, Bangladesh
| | | | | | - Tapan Behl
- Chitkara College of Pharmacy, Chitkara University, Chandigarh, India
| | - Asma Perveen
- Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Government College University, Faisalabad, Pakistan
| | - Abdul Hafeez
- Glocal School of Life Sciences, Glocal University, Saharanpur, India
| | - Ghulam Md Ashraf
- Pre-Clinical Research Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| |
Collapse
|
2
|
Cortés N, Andrade V, Maccioni RB. Behavioral and Neuropsychiatric Disorders in Alzheimer’s Disease. J Alzheimers Dis 2018; 63:899-910. [DOI: 10.3233/jad-180005] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Nicole Cortés
- International Center for Biomedicine (ICC), Santiago, Chile
- Laboratory of Cellular and Molecular Neurosciences, Faculty of Sciences, University of Chile, Santiago, Chile
| | - Víctor Andrade
- International Center for Biomedicine (ICC), Santiago, Chile
- Laboratory of Cellular and Molecular Neurosciences, Faculty of Sciences, University of Chile, Santiago, Chile
| | - Ricardo B. Maccioni
- International Center for Biomedicine (ICC), Santiago, Chile
- Laboratory of Cellular and Molecular Neurosciences, Faculty of Sciences, University of Chile, Santiago, Chile
- Department of Neurological Sciences, Faculty of Medicine, East Campus, University of Chile, Santiago, Chile
| |
Collapse
|
3
|
Zhu CJ, Jiang GX, Chen JM, Zhou ZM, Cheng Q. Serum haptoglobin in Chinese patients with Alzheimer's disease and mild cognitive impairment: A case-control study. Brain Res Bull 2018; 137:301-305. [PMID: 29325993 DOI: 10.1016/j.brainresbull.2018.01.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 12/28/2017] [Accepted: 01/04/2018] [Indexed: 01/21/2023]
Abstract
BACKGROUND Serum level of Haptoglobin (Hp) maybe associated with Alzheimer's disease (AD) and mild cognitive impairment (MCI). OBJECTIVE To investigate associations between serum Hp and AD, as well as between Hp and MCI. METHODS Serum levels of Hp were measured and analyzed for 51 patients with AD, 139 patients with MCI and their healthy controls matched with sex and age. All study subjects were from a survey among residents aged 60 years and over in a community located in the southwest suburb of Shanghai. RESULTS Serum levels of Hp were observed significantly higher in AD and MCI cases than controls (both p < 0.0001). A significant positive correlation was found between Hp and Activities of Daily Living (ADL) score (rs = 0.430, p = 0.007), as well as between Hp and Clinical Dementia Rating (CDR) score (rs = 0.359, p = 0.027) in all AD patients. According to the receiver operating characteristic (ROC) curve analysis, the optimal cut-off point for Hp was found to be 67.50 μg/ml (sensitivity, 0.902; specificity, 0.745) in AD patients, and 44.76 μg/ml (sensitivity, 0.986; specificity, 0.403) in MCI patients. CONCLUSION Elevated serum levels of Hp were observed in AD and MCI patients than controls. In addition, Hp may correlate with the severity of AD.
Collapse
Affiliation(s)
- Cen-Jing Zhu
- Department of Neurology, Ruijin Hospital affiliated with the School of Medicine, Shanghai Jiao Tong University, 197 Ruijin No. 2 Road, Shanghai, 200025, China; School of Public Health, Shanghai Jiao Tong University, 227 Chong Qing Nan Road, Shanghai, 200025, China
| | - Guo-Xin Jiang
- Department of Learning, Informatics, Management and Ethics, Karolinska Institute, Stockholm, 17177, Sweden
| | - Jin-Mei Chen
- Department of Neurology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University, 280 Mo He Road, Shanghai, 201999,China
| | - Zhi-Ming Zhou
- Sheshan Town Community Health Service Center in Shanghai, 11 Xi Lin Road, Shanghai, 201602, China
| | - Qi Cheng
- Department of Neurology, Ruijin Hospital affiliated with the School of Medicine, Shanghai Jiao Tong University, 197 Ruijin No. 2 Road, Shanghai, 200025, China; School of Public Health, Shanghai Jiao Tong University, 227 Chong Qing Nan Road, Shanghai, 200025, China.
| |
Collapse
|
4
|
Genetic Risk Factors for Complex Forms of Alzheimer’s Disease. NEURODEGENER DIS 2018. [DOI: 10.1007/978-3-319-72938-1_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
|
5
|
Naj AC, Schellenberg GD. Genomic variants, genes, and pathways of Alzheimer's disease: An overview. Am J Med Genet B Neuropsychiatr Genet 2017; 174:5-26. [PMID: 27943641 PMCID: PMC6179157 DOI: 10.1002/ajmg.b.32499] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 09/19/2016] [Indexed: 12/19/2022]
Abstract
Alzheimer's disease (AD) (MIM: 104300) is a highly heritable disease with great complexity in its genetic contributors, and represents the most common form of dementia. With the gradual aging of the world's population, leading to increased prevalence of AD, and the substantial cost of care for those afflicted, identifying the genetic causes of disease represents a critical effort in identifying therapeutic targets. Here we provide a comprehensive review of genomic studies of AD, from the earliest linkage studies identifying monogenic contributors to early-onset forms of AD to the genome-wide and rare variant association studies of recent years that are being used to characterize the mosaic of genetic contributors to late-onset AD (LOAD), and which have identified approximately ∼20 genes with common variants contributing to LOAD risk. In addition, we explore studies employing alternative approaches to identify genetic contributors to AD, including studies of AD-related phenotypes and multi-variant association studies such as pathway analyses. Finally, we introduce studies of next-generation sequencing, which have recently helped identify multiple low-frequency and rare variant contributors to AD, and discuss on-going efforts with next-generation sequencing studies to develop statistically well- powered and comprehensive genomic studies of AD. Through this review, we help uncover the many insights the genetics of AD have provided into the pathways and pathophysiology of AD. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Adam C Naj
- Department of Biostatistics and Epidemiology/Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Gerard D Schellenberg
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| |
Collapse
|
6
|
Cacace R, Sleegers K, Van Broeckhoven C. Molecular genetics of early-onset Alzheimer's disease revisited. Alzheimers Dement 2016; 12:733-48. [DOI: 10.1016/j.jalz.2016.01.012] [Citation(s) in RCA: 304] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/20/2016] [Accepted: 01/28/2016] [Indexed: 01/21/2023]
Affiliation(s)
- Rita Cacace
- Neurodegenerative Brain Diseases group; Department of Molecular Genetics; VIB; Antwerp Belgium
- Laboratory of Neurogenetics; Institute Born-Bunge, University of Antwerp; Antwerp Belgium
| | - Kristel Sleegers
- Neurodegenerative Brain Diseases group; Department of Molecular Genetics; VIB; Antwerp Belgium
- Laboratory of Neurogenetics; Institute Born-Bunge, University of Antwerp; Antwerp Belgium
| | - Christine Van Broeckhoven
- Neurodegenerative Brain Diseases group; Department of Molecular Genetics; VIB; Antwerp Belgium
- Laboratory of Neurogenetics; Institute Born-Bunge, University of Antwerp; Antwerp Belgium
| |
Collapse
|
7
|
Talwar P, Sinha J, Grover S, Rawat C, Kushwaha S, Agarwal R, Taneja V, Kukreti R. Dissecting Complex and Multifactorial Nature of Alzheimer's Disease Pathogenesis: a Clinical, Genomic, and Systems Biology Perspective. Mol Neurobiol 2015; 53:4833-64. [PMID: 26351077 DOI: 10.1007/s12035-015-9390-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 08/11/2015] [Indexed: 01/14/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by loss of memory and other cognitive functions. AD can be classified into familial AD (FAD) and sporadic AD (SAD) based on heritability and into early onset AD (EOAD) and late onset AD (LOAD) based on age of onset. LOAD cases are more prevalent with genetically complex architecture. In spite of significant research focused on understanding the etiological mechanisms, search for diagnostic biomarker(s) and disease-modifying therapy is still on. In this article, we aim to comprehensively review AD literature on established etiological mechanisms including role of beta-amyloid and apolipoprotein E (APOE) along with promising newer etiological factors such as epigenetic modifications that have been associated with AD suggesting its multifactorial nature. As genomic studies have recently played a significant role in elucidating AD pathophysiology, a systematic review of findings from genome-wide linkage (GWL), genome-wide association (GWA), genome-wide expression (GWE), and epigenome-wide association studies (EWAS) was conducted. The availability of multi-dimensional genomic data has further coincided with the advent of computational and network biology approaches in recent years. Our review highlights the importance of integrative approaches involving genomics and systems biology perspective in elucidating AD pathophysiology. The promising newer approaches may provide reliable means of early and more specific diagnosis and help identify therapeutic interventions for LOAD.
Collapse
Affiliation(s)
- Puneet Talwar
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB) Campus, New Delhi, India.,Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi, 110 007, India
| | - Juhi Sinha
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi, 110 007, India
| | - Sandeep Grover
- Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi, 110 007, India.,Department of Paediatrics, Division of Pneumonology-Immunology, Charité University Medical Centre, Berlin, Germany
| | - Chitra Rawat
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB) Campus, New Delhi, India.,Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi, 110 007, India
| | - Suman Kushwaha
- Institute of Human Behaviour and Allied Sciences (IHBAS), Delhi, India
| | - Rachna Agarwal
- Institute of Human Behaviour and Allied Sciences (IHBAS), Delhi, India
| | - Vibha Taneja
- Department of Research, Sir Ganga Ram Hospital, New Delhi, India
| | - Ritushree Kukreti
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB) Campus, New Delhi, India. .,Genomics and Molecular Medicine Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Mall Road, Delhi, 110 007, India.
| |
Collapse
|
8
|
Cocciolo A, Di Domenico F, Coccia R, Fiorini A, Cai J, Pierce WM, Mecocci P, Butterfield DA, Perluigi M. Decreased expression and increased oxidation of plasma haptoglobin in Alzheimer disease: Insights from redox proteomics. Free Radic Biol Med 2012; 53:1868-76. [PMID: 23000119 DOI: 10.1016/j.freeradbiomed.2012.08.596] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 08/09/2012] [Accepted: 08/28/2012] [Indexed: 11/20/2022]
Abstract
Alzheimer disease (AD) is one of the most disabling disorders of the elderly and the number of people worldwide facing dementia is expected to dramatically increase in the near future. Thus, one of the major concerns of modern society is to identify putative biomarkers that serve as a valuable early diagnostic tool to identify a subset of patients with increased risk to develop AD. An ideal biomarker should be present in blood before dementia is clinically confirmed, have high sensitivity and specificity, and be reproducible. Proteomics platforms offer a powerful strategy to reach these goals and recently have been demonstrated to be promising approaches. However, the high variability of technologies and studied populations has led to contrasting results. To increase specificity, we analyzed both protein expression profiles and oxidative modifications (carbonylation) of plasma proteins in mild cognitive impairment (MCI) and AD subjects compared with age-matched controls. Most of the proteins found to have differential levels in MCI and AD confirmed results already obtained in other cohort studies. Interestingly, we applied for the first time in MCI a redox proteomics approach to specifically identify oxidized proteins. Among them, haptoglobin, one of the most abundantly secreted glycoproteins with chaperone function, was found to be either increasingly downregulated or increasingly oxidized in AD and MCI compared with controls. We also demonstrated that in vitro oxidation of haptoglobin affects the formation of amyloid-β fibrils, thus suggesting that oxidized haptoglobin is not able to act as an extracellular chaperone to prevent or slow formation of amyloid-β aggregates. Another chaperone protein, α2-macroglobulin, was found to be selectively oxidized in AD patients compared with controls. Our findings suggest that alterations in proteins acting as extracellular chaperones may contribute to exacerbating amyloid-β toxicity in the peripheral system and may be considered a putative marker of disease progression.
Collapse
Affiliation(s)
- A Cocciolo
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Guerreiro RJ, Gustafson DR, Hardy J. The genetic architecture of Alzheimer's disease: beyond APP, PSENs and APOE. Neurobiol Aging 2012; 33:437-56. [PMID: 20594621 PMCID: PMC2980860 DOI: 10.1016/j.neurobiolaging.2010.03.025] [Citation(s) in RCA: 174] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 03/01/2010] [Accepted: 03/11/2010] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is a complex disorder with a clear genetic component. Three genes have been identified as the cause of early onset familial AD (EOAD). The most common form of the disease, late onset Alzheimer's disease (LOAD), is, however, a sporadic one presenting itself in later stages of life. The genetic component of this late onset form of AD has been the target of a large number of studies, because only one genetic risk factor (APOE4) has been consistently associated with the disease. However, technological advances allow new approaches in the study of complex disorders. In this review, we discuss the new results produced by genome wide association studies, in light of the current knowledge of the complexity of AD genetics.
Collapse
Affiliation(s)
- Rita J Guerreiro
- Laboratory of Neurogenetics, National Institute of Aging, National Institutes of Health, Bethesda, MD, USA.
| | | | | |
Collapse
|
10
|
Choi Y, Marchani EE, Bird TD, Steinbart EJ, Blacker D, Wijsman EM. Genome scan of age-at-onset in the NIMH Alzheimer disease sample uncovers multiple loci, along with evidence of both genetic and sample heterogeneity. Am J Med Genet B Neuropsychiatr Genet 2011; 156B:785-98. [PMID: 21812099 PMCID: PMC3168696 DOI: 10.1002/ajmg.b.31220] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 07/06/2011] [Indexed: 01/01/2023]
Abstract
Alzheimer's disease (AD) is a common neurodegenerative disorder of late life with a complex genetic basis. Although several genes are known to play a role in rare early onset AD, only the APOE gene is known to have a high contribution to risk of the common late-onset form of the disease (LOAD, onset >60 years). APOE genotypes vary in their AD risk as well as age-at-onset distributions, and it is likely that other loci will similarly affect AD age-at-onset. Here we present the first analysis of age-at-onset in the NIMH LOAD sample that allows for both a multilocus trait model and genetic heterogeneity among the contributing sites, while at the same time accommodating age censoring, effects of known genetic covariates, and full pedigree and marker information. The results provide evidence for genomic regions not previously implicated in this data set, including regions on chromosomes 7q, 15, and 19p. They also affirm evidence for loci on chromosomes 1q, 6p, 9q, 11, and, of course, the APOE locus on 19q, all of which have been reported previously in the same sample. The analyses failed to find evidence for linkage to chromosome 10 with inclusion of unaffected subjects and extended pedigrees. Several regions implicated in these analyses in the NIMH sample have been previously reported in genome scans of other AD samples. These results, therefore, provide independent confirmation of AD loci in family-based samples on chromosomes 1q, 7q, 19p, and suggest that further efforts towards identifying the underlying causal loci are warranted.
Collapse
Affiliation(s)
- Yoonha Choi
- Department of Biostatistics, University of Washington, Seattle, WA
| | - Elizabeth E. Marchani
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA
| | - Thomas D. Bird
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA,Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle Division, Seattle, WA,Department of Neurology, University of Washington, Seattle, WA
| | - Ellen J. Steinbart
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle Division, Seattle, WA,Department of Neurology, University of Washington, Seattle, WA
| | - Deborah Blacker
- Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School; Dept of Epidemiology, Harvard School of Public Health; Boston, MA
| | - Ellen M. Wijsman
- Department of Biostatistics, University of Washington, Seattle, WA,Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, WA,Department of Genome Sciences, University of Washington, Seattle, WA,correspondence to Ellen M. Wijsman, Department of Medicine, Division of Medical Genetics, Box 357720, University of Washington, Seattle, WA 98195-7720. (206) 543-8987.
| |
Collapse
|
11
|
Sillén A, Brohede J, Forsell C, Lilius L, Andrade J, Odeberg J, Kimura T, Winblad B, Graff C. Linkage analysis of autopsy-confirmed familial Alzheimer disease supports an Alzheimer disease locus in 8q24. Dement Geriatr Cogn Disord 2011; 31:109-18. [PMID: 21273770 DOI: 10.1159/000323808] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/14/2010] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND/AIMS We have previously reported the results of an extended genome-wide scan of Swedish Alzheimer disease (AD)-affected families; in this paper, we analyzed a subset of these families with autopsy-confirmed AD. METHODS We report the fine-mapping, using both microsatellite markers and single-nucleotide polymorphisms (SNPs), in the observed maximum logarithm of the odds (LOD)-2 unit (LOD(max)-2) region under the identified linkage peak, linkage analysis of the fine-mapping data with additionally analyzed pedigrees, and association analysis of SNPs selected from candidate genes in the linked interval. The subset was made on the criterion of at least one autopsy-confirmed AD case per family, resulting in 24 families. RESULTS Linkage analysis of a family subset having at least one autopsy-confirmed AD case showed a significant nonparametric single-point LOD score of 4.4 in 8q24. Fine-mapping under the linkage peak with 10 microsatellite markers yielded an increase in the multipoint (mpt) LOD score from 2.1 to 3.0. SNP genotyping was performed on 21 selected candidate transcripts of the LOD(max)-2 region. Both family-based association and linkage analysis were performed on extended material from 30 families, resulting in a suggestive linkage at peak marker rs6577853 (mpt LOD score = 2.4). CONCLUSION The 8q24 region has been implicated to be involved in AD etiology.
Collapse
Affiliation(s)
- Anna Sillén
- Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, KI-ADRC, KASPAC, Novum, Sweden
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Marchani EE, Bird TD, Steinbart EJ, Rosenthal E, Yu CE, Schellenberg GD, Wijsman EM. Evidence for three loci modifying age-at-onset of Alzheimer's disease in early-onset PSEN2 families. Am J Med Genet B Neuropsychiatr Genet 2010; 153B:1031-41. [PMID: 20333730 PMCID: PMC3022037 DOI: 10.1002/ajmg.b.31072] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Families with early-onset Alzheimer's disease (AD) sharing a single PSEN2 mutation exhibit a wide range of age-at-onset, suggesting that modifier loci segregate within these families. While APOE is known to be an age-at-onset modifier, it does not explain all of this variation. We performed a genome scan within nine such families for loci influencing age-at-onset, while simultaneously controlling for variation in the primary PSEN2 mutation (N141I) and APOE. We found significant evidence of linkage between age-at-onset and chromosome 1q23.3 (P < 0.001) when analysis included all families, and to chromosomes 1q23.3 (P < 0.001), 17p13.2 (P = 0.0002), 7q33 (P = 0.017), and 11p14.2 (P = 0.017) in a single large pedigree. Simultaneous analysis of these four chromosomes maintained strong evidence of linkage to chromosomes 1q23.3 and 17p13.2 when all families were analyzed, and to chromosomes 1q23.3, 7q33, and 17p13.2 within the same single pedigree. Inclusion of major gene covariates proved essential to detect these linkage signals, as all linkage signals dissipated when PSEN2 and APOE were excluded from the model. The four chromosomal regions with evidence of linkage all coincide with previous linkage signals, associated SNPs, and/or candidate genes identified in independent AD study populations. This study establishes several candidate regions for further analysis and is consistent with an oligogenic model of AD risk and age-at-onset. More generally, this study also demonstrates the value of searching for modifier loci in existing datasets previously used to identify primary causal variants for complex disease traits.
Collapse
Affiliation(s)
- Elizabeth E. Marchani
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, Washington
| | - Thomas D. Bird
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, Washington,Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle Division, Seattle, Washington,Department of Neurology, University of Washington, Seattle, Washington
| | - Ellen J. Steinbart
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle Division, Seattle, Washington,Department of Neurology, University of Washington, Seattle, Washington
| | - Elisabeth Rosenthal
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, Washington
| | - Chang-En Yu
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle Division, Seattle, Washington,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington
| | - Gerard D. Schellenberg
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ellen M. Wijsman
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, Washington,Department of Biostatistics, University of Washington, Seattle, Washington,Department of Genome Sciences, University of Washington, Seattle, Washington,Correspondence to: Dr. Ellen M. Wijsman, Department of Medicine, Division of Medical, Genetics, Box 357720, University of Washington, Seattle,WA98195-7720.
| |
Collapse
|
13
|
Linkage to 20p13 including the ANGPT4 gene in families with mixed Alzheimer's disease and vascular dementia. J Hum Genet 2010; 55:649-55. [PMID: 20596041 DOI: 10.1038/jhg.2010.79] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
This study aimed at identifying novel susceptibility genes for a mixed phenotype of Alzheimer's disease and vascular dementia. Results from a genome scan showed strongest linkage to 20p13 in 18 families, and subsequent fine mapping was performed with both microsatellites and single-nucleotide polymorphisms in 18 selected candidate transcripts in an extended sample set of 30 families. The multipoint linkage peak was located at marker rs2144151 in the ANGPT4 gene, which is a strong candidate gene for vascular disease because of its involvement in angiogenesis. Although the significance of the linkage decreased, we find this result intriguing, considering that we included additional families, and thus the reduced linkage signal may be caused by genetic heterogeneity.
Collapse
|
14
|
Blom ES, Giedraitis V, Arepalli S, Hamshere ML, Adighibe O, Goate A, Williams J, Lannfelt L, Hardy J, Vrièze FWD, Glaser A. Further analysis of previously implicated linkage regions for Alzheimer's disease in affected relative pairs. BMC MEDICAL GENETICS 2009; 10:122. [PMID: 19951422 PMCID: PMC2791756 DOI: 10.1186/1471-2350-10-122] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Accepted: 12/01/2009] [Indexed: 05/25/2023]
Abstract
Background Genome-wide linkage studies for Alzheimer's disease have implicated several chromosomal regions as potential loci for susceptibility genes. Methods In the present study, we have combined a selection of affected relative pairs (ARPs) from the UK and the USA included in a previous linkage study by Myers et al. (Am J Med Genet, 2002), with ARPs from Sweden and Washington University. In this total sample collection of 397 ARPs, we have analyzed linkage to chromosomes 1, 9, 10, 12, 19 and 21, implicated in the previous scan. Results The analysis revealed that linkage to chromosome 19q13 close to the APOE locus increased considerably as compared to the earlier scan. However, linkage to chromosome 10q21, which provided the strongest linkage in the previous scan could not be detected. Conclusion The present investigation provides yet further evidence that 19q13 is the only chromosomal region consistently linked to Alzheimer's disease.
Collapse
Affiliation(s)
- Elin S Blom
- Section of Molecular Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Butler AW, Ng MYM, Hamshere ML, Forabosco P, Wroe R, Al-Chalabi A, Lewis CM, Powell JF. Meta-analysis of linkage studies for Alzheimer's disease--a web resource. Neurobiol Aging 2009; 30:1037-47. [PMID: 19362756 DOI: 10.1016/j.neurobiolaging.2009.03.013] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 03/17/2009] [Accepted: 03/24/2009] [Indexed: 10/20/2022]
Abstract
Familial late-onset Alzheimer's disease (LOAD) shows high heritability. However, with the exception of ApoE, no well-replicated susceptibility genes have been identified to date. Several genome-wide linkage studies have nominated potential susceptibility loci but results are inconsistent, with individual scans showing few significant LOD scores. We have pooled linkage results from five independent genome scans and used the genome search meta-analysis (GSMA) method to analyse these data. The combined sample results in 2206 affected individuals and 785 families from Caucasian and Caribbean Hispanic ethnicities. The Caucasian samples included subjects from the US, the Netherlands and Sweden. Genome-wide suggestive evidence for linkage was observed on chromosomes 1p13.3-q31.1, 7pter-p21.1 and 8p22-p21.1 in the weighted GSMA analysis. The chromosome 8p region achieved the lowest summed rank p-value of 0.001. We also identified seven loci with nominally significant evidence for linkage to 3q12.3-q22.1, 6p21.1-q15, 7p14.1-q21.11, 17q24.3-qter and 19p13.3-qter. The GSMA finding suggests that these loci may harbour susceptibility genes for LOAD. We have also developed a web resource (http://alzres.iop.kcl.ac.uk/) to present additional GSMA analyses with different study selection criteria, facilitate the reanalysis of genome-wide linkage data and provide open access to the GSMA data.
Collapse
Affiliation(s)
- Amy W Butler
- King's College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, London, UK.
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Forsell C, Björk BF, Lilius L, Axelman K, Fabre SF, Fratiglioni L, Winblad B, Graff C. Genetic association to the amyloid plaque associated protein gene COL25A1 in Alzheimer's disease. Neurobiol Aging 2008; 31:409-15. [PMID: 18501477 DOI: 10.1016/j.neurobiolaging.2008.04.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 03/25/2008] [Accepted: 04/14/2008] [Indexed: 12/01/2022]
Abstract
The COL25A1 gene, located in 4q25, encodes the CLAC protein, which has been implicated in Alzheimer's disease (AD) pathogenesis. CLAC was originally identified in amyloid preparations from AD brain and has been shown to be associated with amyloid plaques, inhibition of Abeta-fibril elongation and increased protease resistance of Abeta-fibrils through direct binding to Abeta. These biochemical data as well as the genomic location of the COL25A1 gene in chromosome 4q25 where we previously have reported a weak linkage-signal in Swedish AD families encouraged us to perform a case-control association study of two LD blocks in COL25A1 using 817 AD cases and 364 controls. The LD blocks cover a putative Abeta-binding motif and the variable 3' end of the gene. The analyses indicated association to three of eight analysed SNPs. We found further support for the association by replication in a Swedish population-based longitudinal sample set (n=926). Thus, in addition to the biochemical data, there is now genetic evidence of association between COL25A1 and risk for Alzheimer's disease.
Collapse
Affiliation(s)
- Charlotte Forsell
- Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, KASPAC, Novum, S-141 57 Huddinge, Sweden
| | | | | | | | | | | | | | | |
Collapse
|