Editorial: non-coding RNAs in diseases of the nervous system

The bewildering observation of structural and functional proteins in the body being encoded by just a small fraction of the human genome has led to the discovery of the intriguing fact that >80% of the genome is transcribed into a diverse group of non-coding RNAs (ncRNAs) (ENCODE Project Consortium, 2012). These ncRNAs can be broadly categorized into small ncRNAs (eg. microRNAs), long ncRNAs (lncRNAs) and circular RNAs (circRNAs), which are largely involved in controlling gene expression at transcriptional, post-transcriptional or epigenetic levels (Batista and Chang, 2013). Development of the nervous system is a complex and tightly regulated process, which involves dynamic and precise control of gene expression in a spatio- and temporal-specific manner. It is therefore not surprising that >40% of ncRNAs are found to be specifically expressed in the nervous system (Derrien et al., 2012). Accumulating evidence suggests that they play critical role not only during development but also in the adult stage. Dysregulated function of ncRNA is expected to result in diseases. Emerging evidence suggests that mutation of lncRNA or a dysregulation of their expressions correlates with a variety of disorders in the nervous system, including autism spectrum disorder, amyotrophic lateral sclerosis, Alzheimer's disease, bipolar disorder, Huntington's disease, Parkinson's disease (Li et al., 2019).