This report breaks down Rett Syndrome (RTT) in order to inform and educate patients and their family members on the genetic and symptomatic components. To begin, RTT is a post-natal neurodevelopmental condition that almost exclusively affects females. Its characteristic symptoms include an initial normal development followed by a period of regression where the child loses the ability to perform motor functions and may exhibit autistic-like symptoms. The regression period is followed by a plateau of motor deterioration that can last for decades. Furthermore, the syndrome is believed to be X-linked and fatal in males. The rest of this report will go into further details about the cause and effect of Rett Syndrome.
Genetic Foundation
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2007). The mutations render the transcriptional repressor dysfunctional, and therefore MECP2 is not able to ‘turn off’ genes that are normally turned off during development. This leads to an imbalance in gene expression in the brain, which can have vast neuron impacts and can reduce overall neuronal activity (Chahrour, M., Huda, Z. 2007). Specifically, a study found a decrease in the functional units of the brain, reduced dendrite branching, and shorted and sparse dendrites in the frontal cortex (Neul et al. 2010). Dendrites extend from neurons and their shape is important in processing information in the brain (Harris, K., Spacek, J. 2016). Therefore, it is hypothesized that a reduction in dendrite branching, abundance, and length has a negative impact on neurodevelopment. In addition, since MECP2 increases in abundance post-natal, its dysfunction has the largest impact on post-natal development and can lead to neurodevelopmental abnormalities (Neul et al. 2010). In sum, MECP2 mutations have the largest impact on proper brain development.
Inheritance of Mutations Rett Syndrome is almost exclusively seen within females. Researchers found the syndrome to be X-linked dominant with lethality in males (Amir et al. 1999). The MECP2 gene is found on the X chromosome, however it is rarely inherited from parent to offspring. This is because the MECP2 mutations are spontaneous and generally occur in the sex cells, so only the offspring with the random mutation is affected (Amir et al. 1999).
Symptomatic
Genetic Foundation
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2007). The mutations render the transcriptional repressor dysfunctional, and therefore MECP2 is not able to ‘turn off’ genes that are normally turned off during development. This leads to an imbalance in gene expression in the brain, which can have vast neuron impacts and can reduce overall neuronal activity (Chahrour, M., Huda, Z. 2007). Specifically, a study found a decrease in the functional units of the brain, reduced dendrite branching, and shorted and sparse dendrites in the frontal cortex (Neul et al. 2010). Dendrites extend from neurons and their shape is important in processing information in the brain (Harris, K., Spacek, J. 2016). Therefore, it is hypothesized that a reduction in dendrite branching, abundance, and length has a negative impact on neurodevelopment. In addition, since MECP2 increases in abundance post-natal, its dysfunction has the largest impact on post-natal development and can lead to neurodevelopmental abnormalities (Neul et al. 2010). In sum, MECP2 mutations have the largest impact on proper brain development.
Inheritance of Mutations Rett Syndrome is almost exclusively seen within females. Researchers found the syndrome to be X-linked dominant with lethality in males (Amir et al. 1999). The MECP2 gene is found on the X chromosome, however it is rarely inherited from parent to offspring. This is because the MECP2 mutations are spontaneous and generally occur in the sex cells, so only the offspring with the random mutation is affected (Amir et al. 1999).
Symptomatic