👤 Changanamkandath Rajesh

Cardiometabolic risks affect cognition during aging, yet genetic basis for both remain understudied in Indians. This study constructs an ancestry-matched Indian haplotype reference panel for genotype imputation of 5111 rural Indians. Single-locus, gene-based, conditional genome-wide association analyses are performed on 20 cognitive and 10 cardiometabolic traits, with subsequent follow-up of identified associations through multimodal functional annotation. Furthermore, causal interrelationships between cardiometabolic and cognitive phenotypes by Mendelian randomization are investigated. One novel memory-associated and 17 novel cardiometabolic phenotypes-associated (high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], triglycerides [TG], total cholesterol [TC], TG:HDL, and visceral adiposity index [VAI]) genome-wide significant loci, and multiple genes are identified. AMIGO1 (delayed-recall) and ZPR1-APOA5 (metabolic syndrome) exhibit distinct haplotype structure compared to other populations. Causal roles of cardiometabolic traits on various cognitive domains are identified via genetic instruments in APOC3-APOA4-APOA5-ZPR1-BUD13 among others. These findings illustrate the impact of cardiometabolic factors on cognition in a rural socioeconomically disadvantaged population, advancing efforts to address health disparities. Our newly constructed ancestry-matched haplotype reference panel gives better genotype imputation accuracy for the Indian population. One and 17 novel genome-wide significant single-loci were identified to be associated with cognitive and cardiometabolic traits, respectively. Several subgenome-wide hits for all phenotypes were identified. Collapsing protein truncating variants (PTVs), there were two genes identified to be associated with cardiometabolic traits at a genome-wide level of significance, correcting for multiple phenotypes tested. Haplotypic differences were identified compared to 1000 Genomes superpopulations for genes influencing delayed recall and metabolic syndrome. Adverse causal roles of cardiometabolic traits on cognition were uncovered via genetic instruments in APOC3-APOA4-APOA5-ZPR1-BUD13, among others, through Mendelian randomization. Show less

This study reports the prevalence of five clinically significant variants associated with increased risk of cardiovascular disorders, and variable responses of individuals to commonly prescribed cardiovascular drugs in a South Indian population from the state of Kerala. Genomic DNA isolated from 100 out-patient samples from Kerala were sequenced to examine the frequency of clinically relevant polymorphisms in the genes MYBPC3 (cardiomyopathy), SLCO1B1 (statin-induced myopathy), CYP2C9, VKORC1 (response to warfarin) and CYP2C19 (response to clopidogrel). Our analyses revealed the frequency of a 25 bp deletion variant of MYBPC3 associated with risk of cardiomyopathy was 7%, and the SLCO1B1 "C" allele associated with risk for statin-induced myopathy was 15% in this sample group. Among the other variants associated with dose-induced toxicity of warfarin, VKORC1 (c.1639G>A), was detected at 22%, while CYP2C9*3 and CYP2C9*2 alleles were present at a frequency of 15% and 3% respectively. Significantly, the tested sample population showed high prevalence (66%) of CYP2C19*2 variant, which determines response to clopidogrel therapy. We have identified that certain variants associated with cardiovascular disease and related drug response in the five genes, especially those in VKORC1, CYP2C19 and MYBPC3, are highly prevalent in the Kerala population, with almost 2 times higher prevalence of CYP2C19*2 variant compared with other regions in the country. Since the variants chosen in this study have relevance in disease phenotype and/or drug response, and are detected at a higher frequency, this study is likely to encourage clinicians to perform genetic testing before prescribing therapy. Show less