Exploring the shared genetic etiologies of CHD and Alzheimer’s disease

Congenital heart disease (CHD) affects approximately 1% of infants born each year. While CHD was previously fatal, surgical palliation now allows most patients to survive into adulthood. With more adults living with CHD, there is increasing appreciation for continuing health problems among CHD patients, such as high risk for dementia and Alzheimer’s disease. Recent studies show that APOE modifies neurodevelopmental outcomes in the CHD population (Gaynor JW, J Thoracic Cardiovascular Surgery, 2014) and that CHD patients have higher risk for Alzheimer’s disease (Bagge CN, Circulation, 2018). We hypothesize that CHD and Alzheimer’s have shared genetic causes and modifiers. Further insights into the genetic causes for CHD and dementia may reveal novel genetic relationships between the two diseases and provide possibilities for improvements in long term neurological outcomes for CHD patients. We have performed whole exome sequencing at 80x coverage on a discovery cohort of over 600 CHD patients recruited at the University of Pittsburgh Children’s Hospital and obtained access to a cohort of ~4000 healthy older individuals sequenced by the Medical Genome Reference Bank (MGRB) for use as population-matched controls. Here we will perform case-control association analysis with human next-generation sequencing data to identify SNVs, indels, and CNVs associated with CHD. We request access to sequencing data from the Alzheimer’s Disease Sequencing Project to perform a separate case-control analysis, comparing the Alzheimer’s cohort to the MGRB controls. We will then compare genes and variants that are significantly associated with each disease to identify shared pathways involved in disease pathogenesis. Processing and statistical analysis will be performed on the Pittsburgh Supercomputing Center using GATK, bcftools, PLINK, SKAT, and MAGMA well as custom shell, Python, and R scripts. These studies should help us elucidate the shared genetic etiology of CHD and Alzheimer’s disease. We intend to publish or share any findings from this study with the scientific community by presenting at national scientific meetings.

Congenital heart disease (CHD) affects approximately 1% of infants born each year. While CHD was previously fatal, surgical palliation now allows most patients to survive into adulthood. With more adults living with CHD, there is increasing appreciation for continuing health problems among CHD patients, such as high risk for dementia and Alzheimer’s disease. We hypothesize that CHD and Alzheimer’s have shared genetic causes and modifiers. Further insights into the genetic causes for CHD and dementia may reveal novel genetic relationships between the two diseases and provide possibilities for improvements in long term neurological outcomes for CHD patients. Here we will compare genes and variants that are significantly associated with each disease based on case-control analysis to identify shared pathways involved in disease pathogenesis. In the future, we will study the functional consequences of such mutations using cells and mouse models. These studies should help us to elucidate the shared genetic etiology of CHD and Alzheimer’s disease.