Genetic insights into CRP levels in Indian adolescents: confirming adult genetic associations.

CRP is a biomarker of acute inflammation linked to metabolic complications. Given the rising prevalence of these conditions in India, we investigated the genetic basis of CRP levels in Indian adolescents, an underrepresented group in genetic studies, to identify early markers of metabolic risk. We performed a two-phased genome-wide association study (GWAS; N = 5052) and an independent Exome-wide association study (ExWAS; N = 4547), to identify both common and rare genetic variants associated with CRP levels. The study identified intergenic variants near CRP and CRPP1 genes, and APOC1 gene as the key regulators of CRP levels establishing the universality of these associations. The GWAS identified the variant rs4247360 (PITPNC1) to be associated at a suggestive significance. The ExWAS single variant association identified novel associations in genes FGL1 (rs35431851), C19orf45 (rs608144, rs475923, rs484870), TRAPPC12 (rs11686212) and KIAA0087 (rs17153822). The SKATO analysis of the rare variants highlighted the role of loss of function and missense variants in genes EPS15, CCDC15, ZNF286A, ELF1, B3GNT8, ZNF850, MAP2, and PSG2. The GWAS and ExWAS in the present study validated the association of 56 variants previously reported for CRP levels. The meta-analysis with the CRP GWAS earlier reported in Indian adults revealed the shared genetic architecture of CRP levels across age groups. The gene-set enrichment analysis highlighted the role of CRP-associated genes in inflammatory and cardiometabolic pathways. The study enhances understanding of genetic predispositions to inflammation and metabolic disorders confirming known associations, identifying novel loci, and validating shared genetic architecture across age-groups, guiding targeted prevention for at-risk youth.