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Summary: Long‐term repopulating haematopoietic stem cells (LT‐HSCs) have the ability to reconstitute the entire haematopoietic system following transplantation permanently. Despite great achievements in HSC transplantation, the limited transplantable HSC number, especially LT‐HSCs, remains critical for successful transplantation and broader applications. In this study, we established a defined serum‐free culture system for in vitro expansion of LT‐HSCs. This culture system (E1) expanded LT‐HSCs from umbilical cord blood, human mobilization peripheral blood and bone marrow. These E1‐expanded HSCs reconstituted the haematopoietic and immune systems in primary and secondary transplanted mice in a short time. Better haematopoietic reconstitution was observed in secondary xenografted mice. Moreover, we obtained the comprehensive expression profile and cellular components of LT‐HSCs from umbilical cord blood. Our study provides a valuable tool for LT‐HSC research and may improve clinical applications of HSCs. [ABSTRACT FROM AUTHOR]

Advances in third-generation sequencing technologies provide an opportunity to investigate the complex organizational structure of the genome and unravel the genetic mechanisms of disease and physiological traits. Here we report the sequencing and de novo assembly of a healthy male northern Han Chinese genome and detection of structural variants using only nanopore sequencing data. We performed de novo assembly after filtering the raw data. Then, we aligned the assembled contigs to the human reference genome, and visualized chromosomes plot, which illustrated the contiguity of the nanopore assembly. Additionally, genomic structural variants were detected using a structure variation detection tool with long-read sequencing data. Median coverage depth was 30-fold and the read N50 was 27,136 bp. 96.51% of reads had at least one alignment to the human reference genome. The final assembled genome was 2.85 GB in size, with an N50 contig size of 5.4 MB. We identified 20,085 structural variants. Third-generation sequencing technologies have many advantages in de novo whole-genome assembly and detection of structural variants. Our results provide reference data for disease research, and can be used as a novel population-specific dataset of structural variants to support the efficient development of personalized precision medicine. [ABSTRACT FROM AUTHOR]

Preeclampsia (PE) is one of the major causes of maternal and perinatal mortality worldwide. This study aimed to determine the immunological characteristics of PE patients and normal pregnancy at the T cell receptor beta-chain (TRB) level by using high-throughput sequencing. High-throughput sequencing was performed to analyze the expression of TRB-CDR3 in circulating T cells. T cells were isolated from 36 healthy pregnant women, 24 patients with severe PE, and 18 patients with moderate PE. Rearranged mRNA sequences were assigned to their germline V, D, and J counterparts, and translated into proper amino acids by the IMGT database. In general, PE samples had more TRB-CDR3 reads and types than those of normal pregnant woman in the circulation, but the mean number of TRB-CDR3 reads and unique TRB-CDR3 reads in severe group was lower than that in the moderate group. In PE patients, the V7_9 and V20_1 gene loci were more prevalent than in healthy pregnant women. In addition, 4 kinds of TRB-CDR3 peptides were found to be highly relevant to the pathogenesis of PE. Of them, peptides matched to herpes simplex virus antigen-specific T cells were much lower in PE samples. [ABSTRACT FROM AUTHOR]

Background: Joubert syndrome (JBTS) is a rare genetic disorder that is characterized by midbrain‐hindbrain malformations. Multiple variants in genes that affect ciliary function contribute to the genetic and clinical heterogeneity of JBTS and its subtypes. However, the correlation between genotype and phenotype has not been elucidated due to the limited number of patients available. Methods: In this study, we observed different clinical features in two siblings from the same family. The older sibling was classified as a pure JBTS patient, whereas her younger sibling displayed oral‐facial‐digital defects and was therefore classified as an oral‐facial‐digital syndrome type VI (OFD VI) patient. Next, we performed human genetic tests to identify the potential pathogenic variants in the two siblings. Results: Genetic sequencing indicated that both siblings harbored compound heterozygous variants of a missense variant (c.1067C>T, p.S356F) and a frameshift variant (c.8377_8378del, p.E2793Lfs*24) in CPLANE1 (NM_023073.3). Conclusion: This study reports that two novel CPLANE1 variants are associated with the occurrence of JBTS and OFD VI. These results help elucidate the intrafamilial phenotypic variability associated with CPLANE1 variants. [ABSTRACT FROM AUTHOR]

Background: Joubert syndrome (OMIM 213300) is an autosomal recessive disorder with gene heterogeneity. Causal genes and their variants have been identified by sequencing or other technologies for Joubert syndrome subtypes. Case presentation: A two-year-old boy was diagnosed with Joubert syndrome by global development delay and molar tooth sign of mid-brain. Whole exome sequencing was performed to detect the causative gene variants in this individual, and the candidate pathogenic variants were verified by Sanger sequencing. We identified two pathogenic variants (NM_006346.2: c.1147delC and c.1054A > G) of PIBF1 in this Joubert syndrome individual, which is consistent with the mode of autosomal recessive inheritance. Conclusion: In this study, we identified two novel pathogenic variants in PIBF1 in a Joubert syndrome individual using whole exome sequencing, thereby expanding the PIBF1 pathogenic variant spectrum of Joubert syndrome. [ABSTRACT FROM AUTHOR]

Psoriasis is a T cell-mediated chronic inflammatory skin disease with inflammatory cell infiltrates in the dermis and epidermis. Previous studies suggested that there are some expanded T-cell receptor (TCR) clones in psoriatic skin. However, the effect of psoriasis on the immunological characteristics of TCR in circulating blood has not been reported. To address this, we performed high-throughput sequencing to reveal the immunological characteristics of TCR beta chain (TRB) in both psoriasis patients and healthy controls. Our results revealed that the TRB-CDR3 region of psoriasis patients had distinctive immunological characteristics compared with that of healthy controls, including V gene usage, nt of N addition. In addition, three types of TRB-CDR3 peptides were found highly relevant to psoriasis. Our findings show the comprehensive characteristics of psoriasis on the TRB-CDR3 repertoire of circulating blood at sequence-level resolution. These findings may contribute to a better understanding of the pathogenesis of psoriasis and open opportunities to explore potential therapeutic targets. [ABSTRACT FROM AUTHOR]

Background: Joubert syndrome (JS, OMIM: 213300) is a recessive developmental disorder characterized by cerebellar vermis hypoplasia and a distinctive mid‐hindbrain malformation called the "molar tooth sign" on axial magnetic resonance imaging. To date, more than 35 ciliary genes have been identified as the causative genes of JS. Methods: Whole exome sequencing was performed to detect the causative gene mutations in a Chinese patient with JS followed by Sanger sequencing. RT‐PCR and Sanger sequencing were used to confirm the abnormal transcript of centrosomal protein 104 (CEP104, OMIM: 616690). Results: We identified two novel heterozygous mutations of CEP104 in the proband, which were c.2364+1G>A and c.414delC (p.Asn138Lysfs*11) (GenBank: NM_014704.3) and consistent with the autosomal recessive inheritance mode. Conclusion: Our study reported the fourth case of JS patients with CEP104 mutations, which expands the mutation spectrum of CEP104 and elucidates the clinical heterogeneity of JS. [ABSTRACT FROM AUTHOR]