COMPARISON OF ENTROPY AND ENSEMBLE-BASED FEATURE SELECTION THROUGH NETWORK ANALYSIS OF ALZHEIMERS DISEASE-ASSOCIATED VARIANTS

2022-2-7
Rafatov, Sevda
Alzheimer’s Disease (AD) is a complex, progressive and irreversible brain disorder that slowly destroys memory and thinking skills and eventually loses the ability to do daily tasks. Our group is currently developing in-silico AD models in which genotyping and phenotyping data are integrated for the differential diagnosis Late-On-Set AD (LOAD) cases. Meta-analysis of four different LOAD data sets provided by ADNI and dbGAP, which includes the genotyping data of more than 5000 LOAD patients, is done. In this study, we provided the biological interpretation of the variants selected through two different approaches, namely entropy and ensemble modeling. First, the LOAD-associated variants are annotated for their genomic location, consequence, gene and protein products, and biological pathways. The protein-coding variants prioritized were selected for experimental validation based on their relationship with LOAD-related biological pathways after network, PPI, and enrichment analysis. For 32 variants, pyrosequencing primers were designed, and sequencing primers were optimized. As a part of the study, a case-control group with 43 LOAD diagnosed and 38 healthy participants were formed, and genotyping for the prioritized variants was completed. We have shown that machine learning models capture hidden, new, and informative patterns by considering nonlinear interactions where multiple variants determine the risk. Further analysis of interconnected networks for selected genes and proteins can identify affected biological pathways underlying the molecular etiology of AD susceptibility. Understanding the affected molecular pathways can reveal potential causative variants that lead to novel preventative therapeutics for AD.

Suggestions

COMPARATIVE ANALYSIS OF BRAIN CELL CULTURES AND TISSUES IN ALZHEIMER’S DISEASE BASED ON DIFFERENTIAL EXPRESSION AND GENE SET ENRICHMENT
Burduroğlu, Hüseyin Cahit; Aydın Son, Yeşim; Department of Bioinformatics (2023-1-25)
Alzheimer’s disease is currently the most common cause of dementia in the world. It is a neurodegenerative disease that is diagnosed neuropathologically by observing B-amyloid plaques and neurofibrillary tangles in the brain. Transcriptional differentiations, protein regulations, and the interactions in between have been investigated by recent studies to understand from which brain cell type the disease stems, such as microglia, astrocytes, and neurons. These studies are mostly performed on brain tiss...
Understanding the link between alzheimer’s disease and type 2 diabetesin terms of metabolic alterations
Lüleci, Hatice Büşra; Çakır, Tunahan (Orta Doğu Teknik Üniversitesi Enformatik Enstitüsü; 2022-10)
UNDERSTANDING THE LINK BETWEEN ALZHEIMER’S DISEASE AND TYPE 2 DIABETES IN TERMS OF METABOLIC ALTERATIONS Hatice Büşra Lüleci, Tunahan Çakır Department of Bioengineering, Gebze Technical University, Kocaeli, Turkey ABSTRACT Alzheimer’s disease (AD) is a type of dementia that causes impairment in memory, reasoning, and thinking. Type 2 diabetes (T2D) is common in the general elderly population and is significantly associated with a higher risk of dementia. However, metabolic alterations responsible for this a...
Gene-level pathogenicity scores for alzheimer’s disease using genomic variants from rna-seq data
Bozkurt, Fatma Betül; İlgün, Atılay; Uzuner, Dilara; Çakır, Tunahan (Orta Doğu Teknik Üniversitesi Enformatik Enstitüsü; 2022-10)
Alzheimer’s disease (AD) is a complex neurodegenerative disorder affecting millions of people worldwide. Next-generation sequencing technologies such as whole-exome/genome sequencing have been widely used for detecting the variants in the genome to understand the disease etiology and unravel underlying molecular mechanisms. Alternatively, RNA-Seq data can also be used to detect variants. Since AD is a complex disease, several variants are involved in the disease pathogenesis. By using scoring algorithms, it...
Investigating conversion from mild cognitive impairment to alzheimer's disease using latent space manipulation
Ayvaz, Deniz Sezin; Baytaş, İnci M. (Orta Doğu Teknik Üniversitesi Enformatik Enstitüsü; 2022-10)
Alzheimer’s disease, a progressive neurologic disorder, is the most common cause of dementia, affecting millions worldwide. Mild Cognitive Impairment (MCI) is considered an intermediate stage before Alzheimer's. Early prediction of the conversion from MCI to Alzheimer's is crucial to take necessary precautions for decelerating the disease progression and developing suitable treatments. This study proposes a deep learning framework to identify patients whose diagnoses might change from MCI to Alzheimer’s in ...
Computer-aided diagnosis of alzheimer’s disease and mild cognitive impairment with MARS/CMARS classification using structural MR images
Çevik, Alper; Eyüboğlu, Behçet Murat; Weber, Gerhard Wilhelm; Department of Biomedical Engineering (2017)
Early detection of Alzheimer’s disease (AD) and its prodromal stage, amnestic mild cognitive impairment (MCI), has drawn remarkable attention in recent years. Despite the impressive developments in fields of image analysis, pattern classification, and machine learning, no computer-aided diagnosis system has yet been a part of the clinical routine to diagnose the AD. This thesis study aims to propose a thorough procedure which involves detecting the early signs of disease-originated deformations by fully-aut...
Citation Formats
S. Rafatov, “COMPARISON OF ENTROPY AND ENSEMBLE-BASED FEATURE SELECTION THROUGH NETWORK ANALYSIS OF ALZHEIMERS DISEASE-ASSOCIATED VARIANTS,” M.S. - Master of Science, Middle East Technical University, 2022.