Genetic mechanisms that predispose people to type 2 diabetes (T2D) and cardiovascular disease (CVD) remain poorly understood, partly because of a lack of sufficient data on non-European ethnic groups. Show more
Genetic mechanisms that predispose people to type 2 diabetes (T2D) and cardiovascular disease (CVD) remain poorly understood, partly because of a lack of sufficient data on non-European ethnic groups. Extending these evaluations to diverse cohorts is essential for gaining insights into the molecular pathways involved in disease development among human populations. In this study, we aimed to evaluate the genetic connection between the human lipidome and cardiometabolic disorders. We conducted a metabolite genome-wide association study (mGWAS) in a Punjabi population from India, along with multi-layer replication studies using the UK Biobank and other independent European and non-European cohorts. We performed mGWAS using 516 lipid metabolites in 3,000 Punjabi Sikh individuals, and validation was performed in 1.13M Europeans and 15K individuals from Asian Indian ancestry using independent cohorts of the UK Biobank, GeneRISK, DIAMANT, PROMIS, and other studies. We identified 609 SNP-metabolite associations representing 236 SNP-metabolite pairs that attained genome-wide significance (p = 5 × 10-8). Of the 36 SNP-lipid metabolite signals that survived multiple testing correction (p = 1.92 × 10-10), 33 associations were not reported before, and 3 associations were confirmed to be ancestry-specific. Using colocalization analysis, polygenic risk scores, and mendelian randomization approaches, we identified a causal association of LPC O-16:0 with T2D, represented by a lead variant in CD45, a key regulator of T- and B-cell antigen receptor signaling, and is already used as a therapeutic target. Another possible causal relationship of PC 38:4 (C) in protecting against coronary artery disease risk in Asian Indians, attributed to a variant in the untranslated region in the FADS1/2 genes, may be specific to ancestry and/or could not be confirmed in Europeans because of extensive pleiotropy in this region. The main limitation of this study was the absence of an independent validation cohort of Asian Indians from India. The mGWAS of Asian Indians offers new insights into the diverse molecular origins of cardiometabolic diseases and suggests potential pathways for innovative treatments. Our findings highlight the need for additional research on human lipidomics to better understand the downstream effects of the genome and its impact on cardiometabolic health. Show less
Obesity is a major public health crisis associated with high mortality rates. Previous genome-wide association studies (GWAS) investigating body mass index (BMI) have largely relied on imputed data fr Show more
Obesity is a major public health crisis associated with high mortality rates. Previous genome-wide association studies (GWAS) investigating body mass index (BMI) have largely relied on imputed data from European individuals. This study leveraged whole-genome sequencing (WGS) data from 88,873 participants from the Trans-Omics for Precision Medicine (TOPMed) Program, of which 51% were of non-European population groups. We discovered 18 BMI-associated signals (P < 5 × 10 Show less
Obesity is a major public health crisis associated with high mortality rates. Previous genome-wide association studies (GWAS) investigating body mass index (BMI) have largely relied on imputed data fr Show more
Obesity is a major public health crisis associated with high mortality rates. Previous genome-wide association studies (GWAS) investigating body mass index (BMI) have largely relied on imputed data from European individuals. This study leveraged whole-genome sequencing (WGS) data from 88,873 participants from the Trans-Omics for Precision Medicine (TOPMed) Program, of which 51% were of non-European population groups. We discovered 18 BMI-associated signals ( Show less
Hypertriglyceridemia has emerged as a critical coronary artery disease (CAD) risk factor. Rare loss-of-function (LoF) variants in apolipoprotein C-III have been reported to reduce triglycerides (TG) a Show more
Hypertriglyceridemia has emerged as a critical coronary artery disease (CAD) risk factor. Rare loss-of-function (LoF) variants in apolipoprotein C-III have been reported to reduce triglycerides (TG) and are cardioprotective in American Indians and Europeans. However, there is a lack of data in other Europeans and non-Europeans. Also, whether genetically increased plasma TG due to ApoC-III is causally associated with increased CAD risk is still unclear and inconsistent. The objectives of this study were to verify the cardioprotective role of earlier reported six LoF variants of APOC3 in South Asians and other multi-ethnic cohorts and to evaluate the causal association of TG raising common variants for increasing CAD risk. We performed gene-centric and Mendelian randomization analyses and evaluated the role of genetic variation encompassing APOC3 for affecting circulating TG and the risk for developing CAD. One rare LoF variant (rs138326449) with a 37% reduction in TG was associated with lowered risk for CAD in Europeans (p = 0.007), but we could not confirm this association in Asian Indians (p = 0.641). Our data could not validate the cardioprotective role of other five LoF variants analysed. A common variant rs5128 in the APOC3 was strongly associated with elevated TG levels showing a p-value 2.8 × 10 Our results highlight the challenges of inclusion of rare variant information in clinical risk assessment and the generalizability of implementation of ApoC-III inhibition for treating atherosclerotic disease. More studies would be needed to confirm whether genetically raised TG and ApoC-III concentrations would increase CAD risk. Show less