[May the dialogue between genes and environmental factors modify the behavioural phenotype of Rett syndrome and others?].

Formation of a phenotype during development of the human being may result from a specific dialogue between genes and environmental factors. Expression of particular genes is controlled not only on the transcriptional level but also on the level of accessibility of genetic information through the influence for remodelling of chromatin. We characterized Rett syndrome and its molecular basis as an example of the relation between genes and environment and their influence on epigenetic processes determining the gene expression. Examples of importance of DNA methylation in psychiatric disorders were shown.