CYP3A genes and the association between prenatal methylmercury exposure and neurodevelopment

Research output: Contribution to journalArticle


Background Results on the association between prenatal exposure to methylmercury (MeHg) and child neuropsychological development are heterogeneous. Underlying genetic differences across study populations could contribute to this varied response to MeHg. Studies in Drosophila have identified the cytochrome p450 3A (CYP3A) family as candidate MeHg susceptibility genes. Objectives We evaluated whether genetic variation in CYP3A genes influences the association between prenatal exposure to MeHg and child neuropsychological development. Methods The study population included 2639 children from three birth cohort studies: two subcohorts in Seychelles (SCDS) (n = 1160, 20 and 30 months of age, studied during the years 2001–2012), two subcohorts from Spain (INMA) (n = 625, 14 months of age, 2003–2009), and two subcohorts from Italy and Greece (PHIME) (n = 854, 18 months of age, 2006–2011). Total mercury, as a surrogate of MeHg, was analyzed in maternal hair and/or cord blood samples. Neuropsychological development was evaluated using Bayley Scales of Infant Development (BSID). Three functional polymorphisms in the CYP3A family were analyzed: rs2257401 (CYP3A7), rs776746 (CYP3A5), and rs2740574 (CYP3A4). Results There was no association between CYP3A polymorphisms and cord mercury concentrations. The scores for the BSID mental scale improved with increasing cord blood mercury concentrations for carriers of the most active alleles (β[95% CI]: = 2.9[1.53,4.27] for CYP3A7 rs2257401 GG + GC, 2.51[1.04,3.98] for CYP3A5 rs776746 AA + AG and 2.31[0.12,4.50] for CYP3A4 rs2740574 GG + AG). This association was near the null for CYP3A7 CC, CYP3A5 GG and CYP3A4 AA genotypes. The interaction between the CYP3A genes and total mercury was significant (p < 0.05) in European cohorts only. Conclusions Our results suggest that the polymorphisms in CYP3A genes may modify the response to dietary MeHg exposure during early life development.


  • Sabrina Llop
  • N. V. Tran
  • Ferran Ballester
  • Fabio Barbone
  • Aikaterini Sofianou-Katsoulis
  • Jordi Sunyer
  • Ayman Alhamdow
  • Tanzy M Love
  • Gene E Watson
  • Mariona Bustamante
  • Mario Murcia
  • Carmen Iñiguez
  • Conrad F Shamlaye
  • Valentina Rosolen
  • Marika Mariuz
  • Milena Horvat
  • Janja Snoj Tratnik
  • Darja Mazej
  • Edwin van Wijngaarden
  • Philip W Davidson
  • Gary J. Myers
  • Matthew D. Rand
  • Karin Broberg
External organisations
  • Hospital del Mar Medical Research Institute
  • Pompeu Fabra University
  • Karolinska Institutet
  • Center for Genomic Regulation (CRG)
  • Ministry of Health, Seychelles
  • Jožef Stefan Institute
  • Jaume I University
  • CIBER Epidemiology and Public Health (CIBERESP)
  • University of Rochester
  • University of Udine
  • Burlo Garofolo Pediatric Institute
  • Institute of Child Health
  • Centre for Research in Environmental Epidemiology (CREAL)
  • ISGLoBAL Barcelona Institute for Global health
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Environmental Health and Occupational Health
  • Neurology


  • Birth cohort, Cognitive, CYP3A polymorphisms, Methylmercury, Neurotoxicity, Prenatal exposure
Original languageEnglish
Pages (from-to)34-42
Number of pages9
JournalEnvironment International
Publication statusPublished - 2017 Aug 1
Publication categoryResearch