Rett Syndrome: MECP2 gene molecular analysis in Chilean patients

Introduction: Rett syndrome (RTT) is a progressive neurological disorder characterized by regression of psychomotor development in previously healthy girls. Most cases are due to pathogenic variants in the MECP2 gene which encodes for the methyl CpG-binding protein 2. Objective: To describe the frequency and type of pathogenic variants in the MECP2 gene in Chilean female patients with clinical diagnosis of RTT. Patients and Method: Chilean women with clinical suspicion of RTT were invited to participate in the study. Clinical data were collected through a questionnaire. MECP2 pathogenic variants were analyzed by Sanger sequencing method and Multiplex Ligation-dependent Probe Amplification (MLPA) was used to detect duplications or deletions. Results: The study included 14 patients with suspected RTT, of which eight (57%) patients had pathogenic variants. The other patients remain without molecular diagnosis. Conclusions: Pathogenic variants in MECP2 are present in Chilean patients with RTT. It is likely that there are other genes or diagnoses involved in patients without MECP2 findings. As of this study, molecular diagnosis is available in Chile.