RNA-mediated therapies in myotonic dystrophy
DRUG DISCOVERY TODAY
Authors: Overby, Sarah J.; Cerro-Herreros, Estefania; Llamusi, Beatriz; Artero, Ruben
Abstract
Myotonic dystrophy 1 (DM1) is a multisystemic neuromuscular disease caused by a dominantly inherited `CTG' repeat expansion in the gene encoding DM Protein Kinase (DMPK). The repeats are transcribed into mRNA, which forms hairpins and binds with high affinity to the Muscleblind-like (MBNL) family of proteins, sequestering them from their normal function. The loss of function of MBNL proteins causes numerous downstream effects, primarily the appearance of nuclear foci, mis-splicing, and ultimately myotonia and other clinical symptoms. Antisense and other RNA-mediated technologies have been applied to target toxic-repeat mRNA transcripts to restore MBNL protein function in DM1 models, such as cells and mice, and in humans. This technique has had promising results in DM1 therapeutics by alleviating pathogenic phenotypes.
Next-generation sequencing-based molecular diagnosis of neonatal hypotonia in Chinese Population
SCIENTIFIC REPORTS
Authors: Wang, Yan; Peng, Wei; Guo, Hong-Yan; Li, Hui; Tian, Jie; Shi, Yu-Jing; Yang, Xiao; Yang, Yao; Zhang, Wan-Qiao; Liu, Xin; Liu, Guan-Nan; Deng, Tao; Sun, Yi-Min; Xing, Wan-li; Cheng, Jing; Feng, Zhi-Chun
Abstract
Neonatal hypotonia is extremely challenging to diagnose because numerous disorders present similar clinical manifestations. Two panels for diagnosing neonatal hypotonia were developed, which enriches 35 genes corresponding to 61 neonatal hypotonia-related disorders. A cohort of 214 neonates with hypotonia was recruited from 2012 to 2014 in China for this study. Of these subjects, twenty-eight neonates with hypotonia were eliminated according to exclusion criteria and 97 were confirmed using traditional detection methods. The clinical diagnoses of the remaining 89 neonates with hypotonia were approached by targeted next-generation sequencing (NGS). Among the 89 tested neonates, 25 potentially pathogenic variants in nine genes (RYR1, MECP2, MUT, CDKL5, MPZ, PMM2, MTM1, LAMA2 and DMPK) were identified in 22 patients. Six of these pathogenic variants were novel. Of the 186 neonates with hypotonia, we identified the genetic causes for 117 neonates by the traditional detection methods and targeted NGS, achieving a high solving rate of 62.9%. In addition, we found seven neonates with RETT syndrome carrying five mutations, thus expanding the mutation profiles in Chinese neonates with hypotonia. Our study highlights the utility of comprehensive molecular genetic testing, which provides the advantage of speed and diagnostic specificity without invasive procedures.