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.
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.
Eur Psychiatry. 2015 Feb;30(2):303-8. doi: 10.1016/j.eurpsy.2014.11.011. Epub 2014 Dec 16.
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.
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.
MZ twin pairs with the CC genotype for rs406193 SNP showed statistically significant larger intrapair differences in IQ than CT pairs.
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.
尽管成年人的认知能力在很大程度上受个体遗传背景的影响，但也有研究表明，它们也受到环境因素的重要影响。这些影响中的一些是通过表观遗传机制介导的。因此，表观遗传基因 DNMT3B 中的多态性变体与神经认知表现有关。由于同卵双胞胎（MZ）的个体间表型差异可能更大或更小，具体取决于他们的遗传背景对环境因素的敏感性如何，因此采用双胞胎设计来确定 DNMT3B 基因中的特定多态性是否与对丰富（匮乏）环境因素的更好（更差）反应有关。
在一个没有精神病史的 54 对健康 MZ 双胞胎（108 人）的样本中应用变异性基因方法，分析了两个与智力（智商）或工作记忆表现的个体间差异有关的 DNMT3B 多态性。
rs406193 SNP 位点为 CC 基因型的 MZ 双胞胎在智商上的个体间差异明显大于 CT 对。
结果表明，DNMT3B 多态性可能解释了智商对丰富或匮乏环境条件的反应的可变性。因此，所应用的方法被证明是确定认知可塑性遗传标志物的一种有价值的工具。需要进一步的研究来证实这一特定结果，并扩展其他潜在的环境敏感性遗传标志物。
