Snapshot A 2-year-old girl is seen at the pediatrician’s office for unusual hand movements. Her parents also noted decreased interest in playing, loss of eye contact, and some decreased tone. She appears to be calmer than usual as well. Her parents deny any history of developmental disorders in the family. They are counseled about the possibility of a genetic disorder caused by a sporadic mutation and sent for genetic testing. Introduction Overview Rett syndrome is a degenerative neurological disorder affecting females, caused by sporadic mutation in MECP2 gene on the X chromosome Epidemiology Demographics females mutation is fatal in males in utero or soon after birth most common in Swedish, Norwegian, and northern Italian populations ETIOLOGY Pathogenesis characterized by 4 stages stunted development rapid regression of skills pseudostationary late motor deterioration Genetics inheritance pattern sporadic mutations X chromosome gene MECP2, encoding methyl-CpG binding protein-2 (MeCP2) which is expressed in neural and glial cells Presentation Symptoms onset of symptoms typically occur between ages 1-4 common symptoms regression of speech and language, motor, and cognitive skills ataxia stunted growth apraxia hand-wringing behavior often the first sign of disease avoidance of eye contact unusual calmness eventually results in cessation of walking gastrointestinal symptoms constipation gastroesophageal reflux difficulty swallowing Physical exam inspection hand-wringing seizure disorder rigidity scoliosis Imaging Radiograph indication evaluate for scoliosis findings scoliosis Barium swallow indication difficulty swallowing findings may have increased tendency for aspiration Studies Genetic testing diagnostic Differential Autism spectrum disorder (ASD) key distinguishing factor patients with ASD typically do not display regression in developed skills DIAGNOSIS Genetic testing is diagnostic Treatment Treatment is aimed at treating symptoms associated with Rett syndrome Lifestyle specialty therapy modalities physical therapy occupational therapy behavioral therapy Medical anti-epileptic medications indications seizure disorder Surgical gastrostomy tube placement indications difficulty swallowing due to neurodegeneration risk of aspiration Complications Aspiration pneumonia Seizure disorder Prognosis Decreased life expectancy