Background: Rett syndrome is a neurodevelopment syndrome that affects mostly women, caused by mutations in the gene encoding the transcriptional repressor methyl-CpG binding protein 2 (MeCP2) that regulates the expression of a wide range of genes in the hypothalamus, involved in multiple neuropsychiatric disorders. It is characterized by progressive loss of intellectual, motor and communication abilities, seizures and electroencephalographic abnormalities. Associated target-organ damage (cardiac and pulmonary) and skeletal deformations may be present as well as a difficult airway, leading to a challenging anesthetic management.
Case report: We report a case of a 38 years old woman, with Rett syndrome, proposed for a dental extraction under balanced general anesthesia. She had no past surgeries. The preoperative laboratory values were normal.
She was premedicated with 7,5mg of oral Midazolam. A successful rapid sequence induction was done with Fentanyl (0.1 mg), Propofol (170 mg) and Succinylcholine (50 mg, 1mg/kg). 
During the surgery, she presented a prolonged neuromuscular blockade. In the first 60 minutes there were no responses on the Train Of Four (TOF) ratio. The complete reversion of the blockade was only achieved 90 minutes after the Succinylcholine bolus.
Discussion: Despite not being contraindicated, succinylcholine should be carefully used in patients diagnosed with Rett syndrome, due to its reported association with hyperkalemia and resulting arrhythmias. 
In a patient with a prolonged neuromuscular block without any other apparent cause, we question the existence of a possible association between the block and the fact that Mecp2 also regulates the expression of butyrylcholinesterase and acetylcholinesterase.
No other case of prolonged neuromuscular block using succinylcholine in a patient with Rett Syndrome was found in the literature.
References: 
Chahrour, M. et al; Science. May 2008; 320(5880): 1224-1229012
Pierson, J, Mayhew, J.; AANA Journal/October 2001/Vol. 69, No. 5
Kako, H., Int J Clin Exp Med 2013;6(5):393-403
Learning points: Succinylcholine used on Rett syndrome patients should be done carefully, not only due to the already described risk of arrhythmias, but also for an apparent risk of prolonged neuromuscular block.

Prolonged neuromuscular blockade following a bolus of succinylcholine and Rett syndrome- a case report