Human MECP2 peptide

Mutations in X-linked methyl-CpG-binding protein 2 (MECP2) cause Rett syndrome (RTT). To identify functional pathways that could inform therapeutic entry points, we carried out a genetic screen for secondary mutations that improved phenotypes in Mecp2/Y mice after mutagenesis with N-ethyl-N-nitrosourea (ENU). Here, we report the isolation of 106 founder animals that show suppression of Mecp2-null traits from screening 3177 Mecp2/Y genomes. Whole-exome sequencing, genetic crosses, and association analysis identified 22 candidate genes. Additional lesions in these candidate genes or pathway components associate variant alleles with phenotypic improvement in 30 lines. A network analysis shows that 63% of the genes cluster into the functional categories of transcriptional repression, chromatin modification, or DNA repair, delineating a pathway relationship with MECP2. Many mutations lie in genes that modulate synaptic signaling or lipid homeostasis. Mutations in genes that function in the DNA damage response (DDR) also improve phenotypes in Mecp2/Y mice. Association analysis was successful in resolving combinatorial effects of multiple loci. One line, which carries a suppressor mutation in a gene required for cholesterol synthesis, Sqle, carries a second mutation in retinoblastoma binding protein 8, endonuclease (Rbbp8, also known as CtIP), which regulates a DDR choice in double-stranded break (DSB) repair. Cells from Mecp2/Y mice have increased DSBs, so this finding suggests that the balance between homology-directed repair and nonhomologous end joining is important for neuronal cells. In this and other lines, two suppressor mutations confer greater improvement than one alone, suggesting that combination therapies could be effective in RTT.

Background: Patients with Rett syndrome (RTT) present characteristic regression in communication and hand skills, which eventually leads to intellectual and physical disability. Moreover, caregivers of patients with RTT face stressors related to patients' medical and developmental concerns. Given the indications from case reports, this pilot study investigated the effectiveness of music therapy on RTT patients, as well as on parental stress for families of children with RTT. Methods: Families in the study group were enrolled in a twice-weekly 120-minute music therapy program for 24 weeks (n = 11), whereas families in the control group did not receive music therapy (n = 12). Participants were administered the Vineland Adaptive Behavior Scales, Rett Syndrome Clinical Severity Scale, Rett Syndrome Motor Behavioral Assessment, and Parenting Stress Index for caregivers of RTT children before and after the music therapy program. Results: Music therapy improved receptive language, verbal and non-verbal communication skills, and social interaction for RTT patients. In addition, purposeful hand function, breathing patterns, and eye contact were significantly improved. Of note, music therapy also decreased the frequency of epileptic seizures. Lastly, caregivers in the study group exhibited significantly lower stress following the program. Conclusion: The 24-week music therapy program was effective in improving social interaction, communication skills, eye contact, hand function, and reducing seizure frequency among RTT patients. Additionally, music therapy was effective in relieving parenting stress, which may help healthcare providers initiate early intervention strategies that can prevent parenting stress and reduce the risk of depression. Copyright (C) 2019, Formosan Medical Association. Published by Elsevier Taiwan LLC.