MYT1L gene mutation chimerism with autism as the predominant phenotype: a case report and literature review / 中华实用儿科临床杂志

The clinical phenotypes and genotypes of a child with autism spectrum disorder (ASD) concomitant with MYT1L gene mutation were analyzed retrospectively, who was admitted to the Department of Rehabilitation Medicine of Henan Children′s Hospital in April 2019.Whole genome sequencing and copy number variations detection were performed on the child and relevant articles about MYT1L mutation were subjected to a literature review.It was found that this child had a missense mutation of MYT1L gene (c.2186T>G, p.Met729Arg) in 15 exon and was in a state of chimera, with about 10% of the mutation rate.This mutation was not identified in the parents and brother of this patient.A total of 18 reports of MYT1L-related genetic abnormalities were retrieved, including 53 patients in total (including this case), including 22 patients with point mutations and 30 patients containing MYT1L gene region with 2p25.3 chromosomal microdeletions.The incidence of autism was 45.0% (18/40 cases), that of overweight/obesity was 70.2% (33/47 cases) and that of dysnoesia/hypoevolutism was 96.2%(51/53 cases). However, chimeras had relatively mild symptoms.It indicates that the mutation of MYT1L is an important risk factor of ASD, but chimeras have mild symptoms.The children with ASD who are obese or overweight should be alerted to the possible presence of MYT1L mutation, and genetic testing can be performed to confirm the diagnosis and the possibility of chimerism.The spectrum of genetic mutations in ASD was expanded in this study.

Compound heterozygous NDUFS1 variants identified in a Chinese pedigree affected with mitochondrial respiratory chain complex I deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree with suspected mitochondrial functional defects through combined next-generation sequencing (NGS), copy number variation sequencing (CNV-seq), and mitochondrial DNA (mtDNA) sequencing.@*METHODS@#Clinical data of the proband and his family members were collected. The patient and his parents were subjected to family-trio whole-exome sequencing (WES), CNV-seq and mtDNA variant detection. Candidate variant was verified by Sanger sequencing.@*RESULTS@#Trio-WES revealed that the proband has carried compound heterozygous variants of the NDUFS1 gene, including a paternally derived c.64C>T (p.R22X) nonsense variant and a maternally derived c.845A>G (p.N282S) missense variant. Both variants may cause loss of protein function. No variant that may cause the phenotype was identified by CNV-seq and mtDNA variant analysis.@*CONCLUSION@#Children with suspected mitochondrial disorders may have no specific syndromes or laboratory findings. A comprehensive strategy including mtDNA testing may facilitate the diagnosis and early clinical interventions.

Mechanism of long non-coding RNA MALAT1 in promoting migration of hepatocellular carcinoma cells / 军事医学

Objective To investigate whether the long non-coding RNA (lncRNA) metastasis associated lung adenocarcinoma transcript 1 (MALAT1) can act as a competitive endogenous RNA (ceRNA) to promote the migration of hepatocellular carcinoma (HCC) cells.Methods Transient transfection of small interfering RNA (siRNA) against MALAT1 was used to knockdown MALAT1 in HepG2 cells.Transwell assays were employed to assess the migration capabilities of HepG2 cells upon MALAT1 knockdown.RNA pull-down assays were performed to validate the direct binding between MALAT1 and miR-126*.Quantitative reverse transcription PCR (qRT-PCR) and Western blotting assays were used to detect the mRNA and protein levels of the miR-126* target genes.The dysregulation and prognostic significance of MALAT1 and miR-126* were analyzed in the public dataset of The Cancer Genome Atlas (TCGA).Results Compared with the control group, MALAT1 knockdown significantly inhibited the migration of HCC cells.MALAT1, with three miR-126* response elements, directly sponged miR-126* in a sequence-specific manner.The mRNA and protein levels of CXCL12, which was the miR-126* target gene, were significantly down-regulated upon MALAT1 knockdown.The TCGA database showed that MALAT1 was significantly up-regulated in HCC and high expression levels of MALAT1 were significantly associated with poor disease-free survival, whereas an opposite pattern of miR-126* was observed.Conclusion This study suggests that MALAT1 directly sponges miR-126* and upregulates the expression of CXCL12, which in turn promotes the migration of HCC cells.