OBJECTIVE: To explore the clinical features and genetic characteristics of a child with 5q14.3 microdeletion syndrome. METHODS: Whole exome sequencing (WES) and low-coverage massively parallel copy number variation sequencing (CNV-seq) were used to determine the potentially pathogenic variants as well as the copy number variations (CNVs). Candidate CNVs were verified by real-time fluorescence quantitative PCR. RESULTS: The patient presented with psychomotor retardation, epilepsy, peculiar face and hypotonia. The results of WES suggested that he has carried a heterozygous deletion for chr5:86 564 268-88 119 605. CNV-seq indicated that the patient carried a heterozygous deletion of 4.76 Mb heterozygous deletion on chromosome 5q14.3. The MEF2C gene and RASA1 gene in the deletion area were verified by real-time fluorescence quantitative PCR. The results showed that the MEF2C geneand RASA1 gene were heterozygous deletion, which was consistent with the sequencing results. CONCLUSION The child was diagnosed with 5q14.3 microdeletion syndrome. Haploinsufficiency of the MEF2C gene may underlie the manifestations of 5q14.3 microdeletion syndrome.
Chromosome Deletion ; Chromosome Disorders ; DNA Copy Number Variations ; Genetic Testing ; Humans ; Male ; Phenotype ; Whole Exome Sequencing ; p120 GTPase Activating Protein

OBJECTIVETo construct a lentiviral vector of miR-335 gene and verify the target gene of miR-335.

METHODSThe precursor sequence of miR-335 gene was amplified from the genomic DNA by PCR and cloned into the lentiviral vector PLVTHM labeled with GFP. Real-time quantitative RT-PCR was used to detect miR-335 and RASA1 expression in different colorectal cancer cell lines. A recombinant vector psiCHECK-2-RASA1 containing RASA1 3'UTR was constructed followed by site-directed mutagenesis of RASA1 3'UTR to establish the vector psiCHECK-2-RASA1-Mut. Co-transfection of hsa-mir-335 or a NC with these recombined vectors in HEK293A and SW480 cells was performed, and dual-luciferase reporter assay was utilized to examine the changes in luciferase activities. The recombinant PLVTHM-miR335 plasmid was packaged into mature lentivirus by 293FT cells and used to infect SW620 cells. Flow cytometry was employed for sorting the GFP+ cells. The expression of miR-335 and RASA1 were determined by qRT-PCR, and Western blotting was used to detect the expression of RASA1 protein in SW620 cell lines.

RESULTSThe recombinant lentiviral vector PLVTHM-miR335, psiCHECK-2-RASA1 and the mutation expression vector psiCHECK-2-RASA1-Mut were successfully constructed. Dual-luciferase reporter assay showed that miR-335 decreased luciferase activity in cells co-transfected with psiCHECK-2-RASA1. The expression of miR-335 in SW620 cells infected with the lentivirus PLVTHM-miR335 was significantly increased, but the expression of RASA1 showed only slight changes. Overexpression of miR-335 suppressed the expression of RASA1 protein in SW620 cells.

CONCLUSIONWe have successfully constructed the lentiviral vector containing mir-335 gene and a SW620 cell line with miR-335 overexpression. MiR-335 can suppress RASA1 gene expression by targeting the specific sequence of RASA1 3'UTR.

Cell Line, Tumor ; Colorectal Neoplasms ; genetics ; metabolism ; pathology ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; Humans ; Lentivirus ; genetics ; metabolism ; MicroRNAs ; genetics ; metabolism ; Recombinant Proteins ; genetics ; metabolism ; p120 GTPase Activating Protein ; genetics ; metabolism