title: Polymorphic variation in the epigenetic gene DNMT3B modulates the environmental impact on cognitive ability: a twin study.
abstract: BACKGROUND
  Though cognitive abilities in adulthood are largely influenced by individual genetic background, they have also been shown to be importantly influenced by environmental factors. Some of these influences are mediated by epigenetic mechanisms. Accordingly, polymorphic variants in the epigenetic gene DNMT3B have been linked to neurocognitive performance. Since monozygotic (MZ) twins may show larger or smaller intrapair phenotypic differences depending on whether their genetic background is more or less sensitive to environmental factors, a twin design was implemented to determine if particular polymorphisms in the DNMT3B gene may be linked to a better (worse) response to enriched (deprived) environmental factors.
  
  
  METHODS
  Applying the variability gene methodology in a sample of 54 healthy MZ twin pairs (108 individuals) with no lifetime history of psychopathology, two DNMT3B polymorphisms were analyzed in relation to their intrapair differences for either intellectual quotient (IQ) or working memory performance.
  
  
  RESULTS
  MZ twin pairs with the CC genotype for rs406193 SNP showed statistically significant larger intrapair differences in IQ than CT pairs.
  
  
  CONCLUSIONS
  Results suggest that DNMT3B polymorphisms may explain variability in the IQ response to either enriched or impoverished environmental conditions. Accordingly, the applied methodology is shown as a potentially valuable tool for determining genetic markers of cognitive plasticity. Further research is needed to confirm this specific result and to expand on other putative genetic markers of environmental sensitivity.
authors.affiliation: Unitat d'Antropologia, Departament de Biologia Animal, Facultat de Biologia and Institut de Biomedicina (IBUB), Universitat de Barcelona, avenue Diagonal, 643, 08028 Barcelona, Spain; Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Córdova-Palomera
authors.affiliation: Unitat d'Antropologia, Departament de Biologia Animal, Facultat de Biologia and Institut de Biomedicina (IBUB), Universitat de Barcelona, avenue Diagonal, 643, 08028 Barcelona, Spain; Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Fatjó-Vilas
authors.affiliation: Inserm, UMR 894, laboratoire de physiopathologie des maladies psychiatriques, centre de psychiatrie et neurosciences, université Paris-Descartes, PRES Paris Sorbonne Cité, 75014 Paris, France; Service hospitalo-universitaire, faculté de médecine Paris-Descartes, hôpital Sainte-Anne, 75014 Paris, France; GDR3557-institut de psychiatrie, 75014 Paris, France.
authors.forename: O
authors.initials: O
authors.lastname: Kebir
authors.affiliation: Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, Madrid, Spain; Instituto de Investigaciones Biomédicas August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Departamento de Psiquiatría, Instituto Clínico de Neurociencias (ICN), Hospital Clínico, Barcelona, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Gastó
authors.affiliation: Inserm, UMR 894, laboratoire de physiopathologie des maladies psychiatriques, centre de psychiatrie et neurosciences, université Paris-Descartes, PRES Paris Sorbonne Cité, 75014 Paris, France; Service hospitalo-universitaire, faculté de médecine Paris-Descartes, hôpital Sainte-Anne, 75014 Paris, France; GDR3557-institut de psychiatrie, 75014 Paris, France.
authors.forename: M O
authors.initials: MO
authors.lastname: Krebs
authors.affiliation: Unitat d'Antropologia, Departament de Biologia Animal, Facultat de Biologia and Institut de Biomedicina (IBUB), Universitat de Barcelona, avenue Diagonal, 643, 08028 Barcelona, Spain; Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, Madrid, Spain. Electronic address: lfananas@ub.edu.
authors.forename: L
authors.initials: L
authors.lastname: Fañanás
mesh_terms: D000328:Adult; D003071:Cognition; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics*; D004777:Environment; D005260:Female; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D007360:Intelligence / Q000235:genetics*; D007361:Intelligence Tests; D008297:Male; D008570:Memory, Short-Term; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D014430:Twins, Monozygotic / Q000235:genetics*; D000097584:DNA Methyltransferase 3B
chemical_list: D004248:DNA (Cytosine-5-)-Methyltransferases; D005819:Genetic Markers; D000097584:DNA Methyltransferase 3B
keywords: Cognitive plasticity; DNMT3B; Gene-environment; Monozygotic twins