1572 S. D´ıaz de Leo´n-Guerrero et al. morphisms, long sequence polymorphisms or copy number variations in the genes encoding for DNA methyl transferases, histone- modifying enzymes or chromatin-remodeling complexes play a role in the development of neurodevelopmental, neurodegenerative or psychiatric disorders. Acknowledgements We are grateful to Dr Fe´lix Recillas-Targa (Instituto de Fisiolog´ıa Celular, UNAM) for insightful scientiﬁc discussions and to Oswaldo Lo´pez and Virginia Barajas for technical support. This work was supported by DGAPA and CONACYT. The authors declare no conﬂict of interest. 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