The combination of whole-exome sequencing and copy number variation sequencing enables the diagnosis of rare neurological disorders.

This retrospective study aims to investigate the diagnostic yields of multiple strategies of next-generation sequencing (NGS) for children with rare neurological disorders (NDs). A total of 220 pediatric patients with NDs who visited our hospital between Jan 2017 and Dec 2018 and had undergone NGS were included. Most patients were 5 years old or younger, and the number of patients visiting the hospital decreased with age. Seizures were the most common symptom in this cohort. The positive rates for targeted NGS panels (Panel), whole-exome sequencing (WES), and copy number variation sequencing (CNVseq) were 26.5% (9/34), 36.6% (63/172), and 16.7% (22/132), respectively. The positive rate for patients undergoing a combination of WES and CNVseq (WES + CNVseq) was 47.8% (54/113), which was significantly better than the positive rate for patients who underwent WES alone (32.7%, 37/113). A total of 83 variants were found in 42 genes, and SCN1A was the most frequently mutanted gene. Twenty-four CNVs were identified in 22 patients: two CNVs were inherited from the mother; 12 CNVs were de novo; and the CNV origins could not be determined in 10 patients. WES + CNVseq may potentially be the mostly effective NGS approach for diagnosis of rare NDs in pediatric patients.

MiR-342-5p suppresses coxsackievirus B3 biosynthesis by targeting the 2C-coding region.

Coxsackievirus B type 3 (CVB3) is one of the major pathogens associated with human heart disease. miRNAs are a class of short, noncoding RNA that can post-transcriptionally modulate gene expression. By comparing the CVB3 genome and miR-342-5p sequences, we found there were potential miR-342-5p targets in the CVB3 genome. To verify the effect of miR-342-5p on CVB3 biosynthesis, HeLa cells were infected with a Renilla luciferase (RLuc)-expressing CVB3 variant (RLuc-CVB3). We observed that miR-342-5p could significantly inhibit the expression of RLuc in infected cells. In HeLa cells infected with an enhanced green fluorescence protein (EGFP)-expressing CVB3 variant (EGFP-CVB3), EGFP expression was also significantly inhibited by miR-342-5p. The inhibitory effect of miR-342-5p on EGFP expression in EGFP-CVB3-infected cells could be reversed by transfection with anti-miR-342-5p oligonucleotide (AMO-miR-342-5p). Moreover, RNA and protein biosynthesis in wild-type CVB3 was significantly inhibited by miR-342-5p. By mutating the putative targets of miR-342-5p in the 2C-coding region, a sequence, nt4989-nt5015, was identified as the miR-342-5p target. The conserved nt4989-nt5015 sequences of CVB type 1-5 suggest miR-342-5p may exert its inhibitory effect in other types of coxsackievirus besides CVB3. Western blotting indicated that miR-342-5p could indeed suppress protein expression in CVB type 1 and 5. There was a moderate abundance of miR-342-5p in the gut, heart, and brain of Balb/c mice, suggesting that miR-342-5p may interact with CVB3 in vivo. Taken together, these results indicate that miR-342-5p can inhibit CVB3 biosynthesis by targeting its 2C-coding region and therefore may be a potential therapeutic agent in the treatment of CVB3 infection.