RETT SYNDROME, THE ROLE OF MECP2 IN AUTISM — AN OVERALL REVIEW
ResumoIntroduction: The Rett Syndrome (RTT) was first described by Dr. Andreas Rett in 1966 in German (10). It
is a progressive neurodegenerative disorder, which causes mental retardation, seizures and the carrier
also present autistic behavior. It’s a genetic disorder since its inheritance pattern is due to the X
chromosome, technically named X-linked dominant. Consequently, the mostly affected individuals are
females — the statistics shows that 1 in 10.000 - 15.000 is affected by this syndrome, and that more than
95% are de novo mutations. Objectives: To present an overall view about Rett Syndrome, the responsible
gene and its mechanisms, the diagnosis and prognosis, phenotype and symptoms, inheritance patterns
and possible treatments and therapies. Material and Methods: The consulted papers were obtained at
PubMed Central® and Web of Sciece. Search key terms included RTT, MECP2, autism, Rett Syndrome, de
novo mutations. Discussion and Conclusion: RTT is a neurodegenerative disorder responsible for an
autism spectrum and its development is separated in 4 stages: The first stage (stage 1) is named
Stagnation Stage and it occurs between 6 and 18 months, and it’s noticed a developmental delay in
relation to healthy kids. The second stage (stage 2) is called Regression Stage and occurs from 1 to 4 years
old, it is when the autistic behavior becomes perceivable and when happens a regression of acquired
skills. The third stage (stage 3) is the pseudo- stationary phase when the loss of skills stops and hand
features starts to manifest (gait dyspraxia and ataxia). The fourth and last stage (stage 4) is the late motor
decline phase, it is inadequately defined as complete loss of the ability to walk and it happens around the
twenties, it may also cause Parkinson’s disease similar symptoms. It is considered inadequately because
some of RTT patients might have never learnt how to walk (during stages between 2 to 3). Discussion and
Conclusion: RTT is not yet curable but currently researches are leading to a greater view about this
syndrome. Based on that we can be optimistic about a future therapy that will be able to revert symptoms
if early diagnosed. Thus, we have to know the syndrome characteristics, the origin, the mutations
spectrum, the MECP2 function and location and how RTT patients’ cells react to experimental processes.
Scientists have yet to investigate better approaches based on similar inheritance patterns of different.
Amir RE, Van den Veyver IB, Wan M, Tran CQ, Francke U and Zoghbi HY. (1999) Rett
syndrome is caused by mutations in X-linked MECP2 encoding methyl-CpG-binding protein 2. Nature
Genetics, Vol. 23, pp. 185 - 188.
Hass RH. (1988) The history and challenge of Rett syndrome. Journal of Child Neurology, Vol. 3, pp. S3-
Lee JYL, Leonard H, Piek JP and Downs J. (2013) Early development and regression in Rett syndrome.
Clinical Genetics, Vol. 84, Issue 6, pp. 572-576.