ABSTRACT
This chapter offers a detailed scientific explanation of Rett Syndrome (RTT). RTT is a neurodevelopmental disorder caused by a mutation in the X-linked gene encoding for methyl-CpG-binding protein 2 (MeCP2). Genotype and severity of RTT symptoms have been found to be related, affecting the amplitude of comorbidities. The reversibility of the RTT-like phenotype upon restoration of MeCP2 activity and the dramatic consequences of the loss of function of MeCP2 in adult mice argues that MeCP2 seems to be required for the lifelong maintenance of physiological neuronal function. Observations made using animal models should be considered with caution because they could introduce some potential caveats: hemizygous MeCP2 null male mice are frequently used, but the most direct representation of patients with RTT would be MeCP2 heterozygous female mice. Moreover, symptoms of MeCP2 deficiency in mice models, including an abnormal gait, breathing disturbances, and premature lethality in males, appear at a later stage in the development than in humans.
