Novel Loss of Function (G15D) Mutation on RAC2 in a Family with Combined Immunodeficiency and Increased Levels of Immunoglobulin G, A, and E.

Ras-related C3 botulinum toxin substrate 2 (RAC2) is a small guanine nucleotide binding molecule that is exclusively expressed in hematopoietic cell lineages as a switcher. Based on in vivo and/or in vitro model experiments, RAC2 plays important roles in different cells through proliferation, secretion, and phagocytosis. It also performs a suppressing function in immunoglobulin (Ig) switching in Rac2-/- animals or cells. Several RAC2 natural mutations have been described in patients with primary immunodeficiency. RAC2 mutations can be classified into loss-of-function inactivating (LoF-I) and gain-of-function activating mutations according to their functional effects. Only two LoF-I mutations on RAC2 have been reported, including a dominant D57N mutation in several cases that exhibit granulocyte function defects and a recessive D56X mutation in cases with common variable immunodeficiency. Regardless of the type of mutation, most of the reported RAC2 mutant cases have shown reduced IgG, IgA, and IgM levels. Herein, we report on a family with three members that suffer from persistent HPV infection, recurrent respiratory infections, bronchiectasis, and autoimmune disease. The immunologic profile suggests that the family was affected by combined immunodeficiency (CID) with increased serum levels of IgG, IgA, and IgE. Exome sequencing identified a de novo RAC2 mutation (c.44G > A/p.G15D) that was co-segregated with the disease in the family. Gene functional experiments identified that such mutation results in reduced guanosine triphosphate binding activity and RAC2 protein expression. In patients' lymphocytes, impaired aggregation and proliferation effects, decreased mitochondrial membrane potential, and increased levels of cell apoptosis were observed, although no functional abnormalities were detected in neutrophils. To our knowledge, this study was the first to identify a LoF-I mutation of RAC2 affecting lymphocyte function that consequently led to CID and increased levels of serum IgG, IgE, and IgA. This study presents a novel subtype of RAC2-related immune disorder.

Case series of congenital pseudarthrosis of the tibia unfulfilling neurofibromatosis type 1 diagnosis: 21% with somatic NF1 haploinsufficiency in the periosteum.

Up to 84% of patients with congenital pseudarthrosis of the tibia (CPT) present with neurofibromatosis type 1 (NF1) (NF1-CPT). However, the etiology of CPT not fulfilling the NIH diagnostic criteria for NF1 (non-NF1-CPT) is not well understood. Here, we collected the periosteum tissue from the pseudarthrosis (PA) site of 43 non-NF1-CPT patients and six patients with NF1-CPT, together with the blood or oral specimen of trios (probands and unaffected parents). Whole-exome plus copy number variation sequencing, multiplex ligation-dependent probe amplification (MLPA), ultra-high amplicon sequencing, and Sanger sequencing were employed to identify pathogenic variants. The result showed that nine tissues of 43 non-NF1-CPT patients (21%) had somatic mono-allelic NF1 inactivation, and five of six NF1-CPT patients (83.3%) had bi-allelic NF1 inactivation in tissues. However, previous literature involving genetic testing did not reveal somatic mosaicism in non-NF1-CPT patients so far. In NF1-CPT patients, when the results from earlier reports and the present study were combined, 66.7% of them showed somatic NF1 inactivation in PA tissues other than germline inactivation. Furthermore, no diagnostic variants from other known genes (GNAS, AKT1, PDGFRB, and NOTCH3) related to skeletal dysplasia were identified in the nine NF1 positive non-NF1-CPT patients and six NF1-CPT patients. In conclusion, we detected evident somatic mono-allelic NF1 inactivation in the non-NF1-CPT. Thus, for pediatric patients without NF1 diagnosis, somatic mutations in NF1 are important.

MECOM-related disorder: Radioulnar synostosis without hematological aberration due to unique variants.

PURPOSE: The etiology for a considerable proportion of patients with congenital radioulnar synostosis (RUS) remains unclear. This study aimed to investigate the genetic cause of RUS without a known cause. METHODS: Patients with RUS were investigated. Exome sequencing and/or Sanger sequencing was performed. Bioinformatics analysis was also performed. Pathogenicity was evaluated for variants of interest. RESULTS: We identified unique missense variants in MECOM (encodes EVI1) associated with RUS in 8 families. Of them, 6 families had variants in residue R781, including 3 families with R781C (c.2341C>T), 2 families with R781H (c.2342G>A), and 1 family with R781L (c.2342G>T). Another 2 variants included I783T (c.2348T>C) in 1 family and Q777E (c.2329C>G) in 1 family. All these variants were clustered within the ninth zinc finger motif of EVI1. Phenotype evaluation identified that most of these patients with RUS harboring mutant MECOM had finger malformations, but none of them had identifiable hematological abnormalities. Functional experiments showed that MECOM R781C led to alterations in TGF-ß-mediated transcriptional responses. CONCLUSION: This study examined MECOM variants by focusing on RUS instead of hematological abnormalities. The R781 residue in EVI1 is a hotspot for human RUS variants. Mutant MECOM is the second most common cause for familial RUS.

Expanding the genotypes and phenotypes for 19 rare diseases by exome sequencing performed in pediatric intensive care unit.

Phenotypes of some rare genetic diseases are atypical and it is a challenge for pediatric intensive care units (PICUs) to diagnose and manage such patients in an emergency. In this study, we investigated 58 PICU patients (39 deceased and 19 surviving) in critical ill status or died shortly without a clear etiology. Whole exome sequencing was performed of 103 DNA samples from their families. Disease-causing single-nucleotide variants (SNVs) and copy number variants (CNVs) were identified to do genotype-phenotypes analysis. In total, 27 (46.6%) patients received a genetic diagnosis. We identified 34 pathogenic or likely pathogenic SNVs from 26 genes, which are related to at least 19 rare diseases. Each rare disease involved an isolated patient except two patients caused by the same gene ACAT1. The genotypic spectrum was expanded by 23 novel SNVs from gene MARS1, PRRT2, TBCK, TOR1A, ECE1, ARX, ZEB2, ACAT1, CPS1, VWF, NBAS, COG4, and INVS. We also identified two novel pathogenic CNVs. Phenotypes associated with respiratory, multiple congenital anomalies, neuromuscular, or metabolic disorders were the most common. Twenty patients (74.1%) accompanied severe infection, 19 patients (70.1%) died. In summary, our findings expanded the genotypes and phenotypes of 19 rare diseases from PICU with complex characteristics.

Case report: two novel VPS13B mutations in a Chinese family with Cohen syndrome and hyperlinear palms.

BACKGROUND: Cohen syndrome (CS) is an uncommon developmental disease with evident clinical heterogeneity. VPS13B is the only gene responsible for CS. Only few sporadic cases of CS have been reported in China. CASE PRESENTATION: A Chinese family with two offspring-patients affected by developmental delay and intellectual disability was investigated in this study. Exome sequencing was performed, and compound heterozygous mutations in VPS13B were segregated for family members with autosomal recessive disorder. Splicing mutation c.3666 + 1G > T (exon 24) and nonsense mutation c. 9844 A > T:p.K3282X (exon 54) were novel. We revisited the family and learned that both patients are affected by microcephaly, developmental delay, neutropenia, and myopia and have a friendly disposition, all of which are consistent with CS phenotypes. We also found that both patients have hyperlinear palms, which their parents do not have. VPS13B mutations reported among the Chinese population were reviewed accordingly. CONCLUSIONS: This study presents two novel VPS13B mutations in CS. The identification of hyperlinear palms in a family affected by CS expands the phenotype spectrum of CS.

Mosaic variegated aneuploidy syndrome with tetraploid, and predisposition to male infertility triggered by mutant CEP192.

In this study, we report on mosaic variegated aneuploidy (MVA) syndrome with tetraploidy and predisposition to infertility in a family. Sequencing analysis identified that the CEP192 biallelic variants (c.1912C>T, p.His638Tyr and c.5750A>G, p.Asn1917Ser) segregated with microcephaly, short stature, limb-extremity dysplasia, and reduced testicular size, while CEP192 monoallelic variants segregated with infertility and/or reduced testicular size in the family. In 1,264 unrelated patients, variant screening for CEP192 identified a same variant (c.5750A>G, p.Asn1917Ser) and other variants significantly associated with infertility. Two lines of Cep192 mice model that are equivalent to human variants were generated. Embryos with Cep192 biallelic variants arrested at E7 because of cell apoptosis mediated by MVA/tetraploidy cell acumination. Mice with heterozygous variants replicated the predisposition to male infertility. Mouse primary embryonic fibroblasts with Cep192 biallelic variants cultured in vitro showed abnormal morphology, mitotic arresting, and disruption of spindle formation. In patient epithelial cells with biallelic variants cultured in vitro, the number of cells arrested during the prophase increased because of the failure of spindle formation. Accordingly, we present mutant CEP192, which is a link for the MVA syndrome with tetraploidy and the predisposition to male infertility.

Applying Blockchain Technology in Network Public Opinion Risk Management System in Big Data Environment.

Network public opinion represents public social opinion to a certain extent and has an important impact on formulating national policies and judgment. Therefore, China and other countries attach great importance to the study of online public opinion. However, the current researches lack the combination of theory and practical cases and lack the intersection of social and natural sciences. This work aims to overcome the technical defects of traditional management systems, break through the difficulties and pain points of existing network public opinion risk management, and improve the efficiency of network public opinion risk management. Firstly, a network public opinion isolation strategy based on the infectious disease propagation model is proposed, and the optimal control theory is used to realize a functional control model to maximize social utility. Secondly, blockchain technology is used to build a network public opinion risk management system. The system is used to conduct a detailed study on identifying and perceiving online public opinion risk. Finally, a Chinese word segmentation scheme based on Long Short-Term Memory (LSTM) network model and a text emotion recognition scheme based on a convolutional neural network are proposed. Both schemes are validated on a typical corpus. The results show that when the system has a control strategy, the number of susceptible drops significantly. Two days after the public opinion is generated, the number of susceptible people decreased from 1,000 to 250; 3 days after the public opinion is generated, the number of susceptible people stabilized. 2 days after the public opinion is generated, the number of lurkers increased from 100 to 620; 3 days after the public opinion is generated, the number of lurkers stabilized. The data demonstrate that the designed isolation control strategy is effective. Changes in public opinion among infected people show that quarantine control strategies played a significant role in the early days of Corona Virus Disease 2019. The rate of change in the number of infections is more affected when quarantine controls are increased, especially in the days leading up to the outbreak. When the system adopts the optimal control strategy, the influence scope of public opinion becomes smaller, and the control becomes easier. When the dimension of the word vector of emergent events is 200, its accuracy may be higher. This method provides certain ideas for blockchain and deep learning technology in network public opinion control.

Mutant B3GALT6 in a Multiplex Family: A Dominant Variant Co-Segregated With Moderate Malformations.

B3GALT6 is a well-documented disease-related gene. Several B3GALT6-recessive variants have been reported to cause Ehlers-Danlos syndrome (EDS). To the best of our knowledge, no dominant B3GALT6 variant that causes human disease has been reported. In 2012, we reported on a three-generation, autosomal-dominant family with multiple members who suffered from radioulnar joint rotation limitation, scoliosis, thick vermilion of both lips, and others, but the genetic cause was unknown. Here, exome sequencing of the family identified mutant B3GALT6 as the cause of the multiplex affected family. We observed that, in the compound heterozygous pattern (i.e., c.883C>T:p.R295C and c.510_517del:p.L170fs*268), mutant B3GALT6 led to severe consequences, and in the dominant pattern, an elongated B3GALT6 variant co-segregated with moderate phenotypes. The functional experiments were performed in vitro. The R295C variant led to subcellular mislocalization, whereas the L170fs*268 showed normal subcellular localization, but it led to an elongated protein. Given that most of the catalytic galactosyltransferase domain was disrupted for the L170fs*268 (it is unlikely that such a protein has activity), we propose that the L170fs*268 occupies the normal B3GALT6 protein position in the Golgi and exerts a dominant-negative effect.

A genotype and phenotype analysis of SMAD6 mutant patients with radioulnar synostosis.

BACKGROUND: SMAD6 variants have been reported in patients with radioulnar synostosis (RUS). This study aimed to investigate the genotypes and phenotypes for a large cohort of patients with RUS having mutant SMAD6. METHODS: Genomic DNA samples were isolated from 251 RUS sporadic patients (with their parents) and 27 RUS pedigrees. Sanger sequencing was performed for the SMAD6 coding regions. For positive probands, co-segregation and parental-origin analysis of SMAD6 variants and phenotypic re-evaluation were performed for their family members. RESULTS: We identified 50 RUS probands with SMAD6 variants (13 co-segregated with RUS in pedigrees and 37 in RUS-sporadic patients). Based on the new and previous data, we identified SMAD6 mutated in 16/38 RUS pedigrees and 61/393 RUS sporadic patients, respectively. Overall, 93 SMAD6 mutant patients with RUS were identified, among which 29 patients had unilateral RUS, where the left side was more involved than the right side (left:right = 20:9). Female protective effects and non-full penetrance were observed, in which only 6.90% mothers (vs. ~50% fathers) of SMAD6 mutant RUS probands had RUS. Pleiotropy was observed as a re-evaluation of SMAD6 mutant families identified: (a) three families had axial skeletal malformations; (b) two families had polydactyly; and (c) eight families had other known malformations. CONCLUSION: SMAD6 was mutated in 42.11% RUS pedigrees and 15.52% RUS sporadic patients. The RUS patients with SMAD6 variants exhibit both non-full-penetrance, variable expressivity, pleiotropy, female protective effects, and the left side is more susceptible than the right side.

Disorder of Sexual Development Males With XYY in Blood Have Exactly X/XY/XYY Mosaicism in Gonad Tissues.

Y chromosome represents masculinization. The extra Y chromosome of XYY patients usually leads to over-masculinization phenotypes. The occurrence of several DSD cases with XYY in blood is controversial. Is XYY associated with disorder of sex development (DSD)? What is the mechanism behind DSD in males with XYY in blood? To this end, this study retrospectively analyzed blood-karyotype data of 4,437 DSD male children and karyotypes data of 6,259 newborn males as the control. Exome sequencing (ES) was performed to test whether the patients with DSD and with XYY in blood had other variants on known DSD-genes. Testicular biopsy was performed. Fluorescence in situ hybridization (FISH) was used to test whether a sex chromosome mosaicism was present in the oral epithelial cells or gonad tissue of patients with DSD and with XYY in blood. Among 4,437 DSD males who received cytogenetic evaluation, 14 patients with 47,XYY were identified. By contrast, five individuals among the 6,259 controls had 47,XYY. XYY in blood is more frequent among males with DSD than in other males (p = 0.004). The XYY karyotypes were confirmed again by GTG-banding in blood samples and by FISH performed on oral epithelial cells. ES on seven XYY DSD patients was successfully performed, but results did not identify any pathogenic variant on 55 known DSD genes. Gonad biopsy (n = 3) revealed testicular dysplasia and true hermaphroditism. FISH of gonad tissues (n = 3) showed that all of the samples had mosaic for X/XY/XYY. This study is the first to investigate the relationship between XYY in blood and DSD. The knowledge that XYY is in the blood and in oral cells have X/XY/XYY mosaicism in gonadal tissue is new for both researchers and clinicians who seek to understand the genetic basis of DSD males.

High-Efficiency Monolayer Molybdenum Ditelluride Light-Emitting Diode and Photodetector.

Developing a high-efficiency and low-cost light source with emission wavelength transparent to silicon is an essential step toward silicon-based nanophotonic devices and micro/nano industry platforms. Here, a near-infrared monolayer MoTe2 light-emitting diode (LED) has been demonstrated and its emission wavelength is transparent to silicon. By taking advantage of the quantum tunneling effect, the device has achieved a very high external quantum efficiency (EQE) of 9.5% at 83 K, which is the highest EQE obtained from LED devices fabricated from monolayer TMDs so far. When the device is operated as a photodetector, the MoTe2 device exhibits a strong photoresponsivity at resonant wavelength 1145 nm. The low dark current of ∼5pA and fast response time 5.06 ms are achieved due to suppression of hBN tunneling layer. Our results open a new route for the investigation of novel near-infrared silicon integrated optoelectronic devices.