title: 'Mendelian randomization': an approach for exploring causal relations in epidemiology.
abstract: OBJECTIVE
  To assess the current status of Mendelian randomization (MR) approach in effectively influencing the observational epidemiology for examining causal relationships.
  
  
  METHODS
  Narrative review on studies related to principle, strengths, limitations, and achievements of MR approach.
  
  
  RESULTS
  Observational epidemiological studies have repeatedly produced several beneficiary associations which were discarded when tested by standard randomized controlled trials (RCTs). The technique which is more feasible, highly similar to RCTs, and has the potential to establish a causal relationship between modifiable exposures and disease outcomes is known as MR. The technique uses genetic variants related to modifiable traits/exposures as instruments for detecting causal and directional associations with outcomes.
  
  
  CONCLUSIONS
  In the last decade, the approach of MR has methodologically developed and progressed to a stage of high acceptance among the epidemiologists and is gradually expanding the landscape of causal relationships in non-communicable chronic diseases.
authors.affiliation: Department of Anthropology, University of Delhi, Delhi 110007, India.
authors.forename: V
authors.initials: V
authors.lastname: Gupta
authors.affiliation: Public Health Foundation of India, Gurgaon 122002, India.
authors.forename: G K
authors.initials: GK
authors.lastname: Walia
authors.affiliation: Department of Anthropology, University of Delhi, Delhi 110007, India.
authors.forename: M P
authors.initials: MP
authors.lastname: Sachdeva
mesh_terms: D015984:Causality; D004812:Epidemiologic Methods; D014644:Genetic Variation; D055106:Genome-Wide Association Study; D006801:Humans; D057182:Mendelian Randomization Analysis / Q000379:methods*; D011897:Random Allocation; D016032:Randomized Controlled Trials as Topic
keywords: Epidemiology; Genome-wide association studies; India; Mendelian randomization