Adverse childhood experiences (ACEs) are usually understood as socially patterned exposures shaped by family, environmental, and intergenerational factors; however, gene-environment correlation (rGE) theory proposes that genetically influenced traits may also shape vulnerability to adversity through evocative or passive processes. This study examined whether polymorphisms in genes involved in stress-related pathways (FKBP5, MAOA, NR3C1, HTR2A, DRD2, SNAP25, and NTF3) are associated with ACE exposure among young adults in the Delhi-National Capital Region (Delhi-NCR), India.

In this cross-sectional genetic association study, data from 723 college-going young adults were analyzed. ACE exposure was assessed using the ACE-International Questionnaire (ACE-IQ), and candidate gene polymorphisms were genotyped using the Sequenom MassARRAY iPLEX platform.

Significant associations were found between FKBP5 (rs7748266) and MAOA (rs5906883) polymorphisms and higher ACE exposure, both in terms of overall scores and specific domains such as emotional abuse, household substance use, and household mental illness. The CT genotype of FKBP5 and the AC/CC genotypes of MAOA were associated with increased likelihood of exposure to moderate and high ACEs. A significant linear association was identified between ACE scores and the minor allele count of MAOA rs5906883, suggesting a cumulative genetic effect.

The study provides evidence that certain genetic variation in stress-regulation pathways may contribute to differential ACE exposures. The findings support the role of genetic factors in shaping environmental risk, consistent with rGE processes, and highlight the importance of integrating genetic and socio-environmental perspectives to better understand how vulnerability to childhood adversity is patterned across populations.