A novel heterozygous variant p.(Trp538Arg) of SYNM is identified by whole-exome sequencing in a Chinese family with dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is a relatively frequent myocardial disease that may lead to heart failure, syncope, and sudden cardiac death. Genetic factors play important roles in the etiology of the disease. To date, at least 50 genes have been identified in patients with DCM, among them, only three mutations have been reported in Synemin (SYNM) gene. In this study, we investigate a Chinese family of three generations with four patients with DCM. Employing whole-exome sequencing (WES) and bioinformatics strategies, a novel heterozygous missense mutation p.(Trp538Arg) of SYNM was identified and cosegregated with the affected family members. The missense mutation locates in the C-terminal domain of SYNM and leads to a substitution of tryptophan by arginine and may cause the structure change of synemin protein. In conclusion, we employed WES to detect the mutations of DCM patients and identified a novel likely pathogenic mutation in SYNM gene. Our study not only expands the spectrum of SYNM mutations, it further confirms that mutations in SYMN may underlie nonfamilial DCM, and offers genetic testing information to additional DCM patients.

RTN3 deficiency exacerbates cisplatin-induced acute kidney injury through the disruption of mitochondrial stability.

Reticulum 3 (RTN3) is an endoplasmic reticulum (ER) protein that has been reported to act in neurodegenerative diseases and lipid metabolism. However, the role of RTN3 in acute kidney injury (AKI) has not been explored. Here, we employed public datasets, patient data, and animal models to explore the role of RTN3 in AKI. The underlying mechanisms were studied in primary renal tubular epithelial cells and in the HK2 cell line. We found reduced expression of RTN3 in AKI patients, cisplatin-induced mice, and cisplatin-treated HK2 cells. RTN3-null mice exhibit more severe AKI symptoms and kidney fibrosis after cisplatin treatment. Mitochondrial dysfunction was also found in cells with RTN3 knockdown or knockout. A mechanistic study revealed that RTN3 can interact with HSPA9 in kidney cells. RTN3 deficiency may disrupt the RTN3-HSPA9-VDAC2 complex and affect MAMs during ER-mitochondrion contact, which further leads to mitochondrial dysfunction and exacerbates cisplatin-induced AKI. Our study indicated that RTN3 was important in the kidney and that a decrease in RTN3 in the kidney might be a risk factor for the aggravation of AKI.

Correction to: Increased RTN3 phenocopies nonalcoholic fatty liver disease by inhibiting the AMPK-IDH2 pathway.

[This corrects the article DOI: 10.1002/mco2.226.].

Profiles of HBcrAg and pgRNA in Pregnant Women With Chronic HBV Under Different Disease Phases and Antiviral Prophylaxis.

Background: Pregnant women with chronic hepatitis B (CHB) exhibit unique clinical features in terms of postpartum immune system reconstitution and recovery from pregnancy-related changes. However, current studies focus primarily on the outcomes of maternal-infant transmission and postpartum hepatitis flares. We aimed to evaluate the profiles of hepatitis B core-related antigen (HBcrAg) and pregenomic RNA (pgRNA) in pregnant women with CHB. Methods: This retrospective analysis included treatment-naïve pregnant women with CHB who were followed up regularly in an outpatient clinic from 2014 to 2021. Baseline HBcrAg and pgRNA levels were compared in patients with different disease phases. Changes in these parameters were examined in a subset of patients receiving antiviral prophylaxis. HBcrAg and pgRNA levels were measured before treatment, at 32 weeks of gestation, and postpartum. Results: The final analysis included a total of 121 patients, 100 of whom were hepatitis B e antigen (HBeAg)-positive (96 and 4 in the immune-tolerant and -indeterminate phases, respectively) and 21 of whom were HBeAg-negative (6 and 15 in the immune-active and -inactive carrier phases, respectively). The HBeAg-negative group vs the HBeAg-positive group had lower levels of baseline HBcrAg (median [interquartile range {IQR}], 3.7 [3.0-5.9] vs 8.6 [8.4-8.7] log10 U/mL; P < .01) and pgRNA (median [IQR], 0.0 [0.0-2.5] vs 7.8 [7.6-8.1] log10 copies/mL; P < .01). The serum levels of HBcrAg and pgRNA were highest in immune-tolerant carriers and lowest in immune-inactive carriers. In HBeAg-positive patients, the correlation coefficients of HBcrAg and pgRNA with hepatitis B virus (HBV) DNA were 0.40 and 0.43, respectively; in HBeAg-negative patients, they were 0.53 and 0.51, respectively (all P < .05). The correlation coefficients with hepatitis B surface antigen (HBsAg) were 0.55 and 0.52 (P < .05) in HBeAg-positive patients, respectively, while in HBeAg-negative patients they were 0.42 and 0.37, respectively (P > .05). Among 96 patients receiving antiviral prophylaxis, we detected a rapid decrease in HBV DNA to an undetectable level during treatment but relatively stable levels of pgRNA and HBcrAg. Conclusions: HBcrAg and pgRNA levels are lower in HBeAg-negative patients than in HBeAg-positive patients. These 2 markers are significantly associated with HBV DNA irrespective of HBeAg status, while they are significantly associated with HBsAg only in HBeAg-positive patients.

Single-cell transcriptomic profiling reveals decreased ER protein Reticulon3 drives the progression of renal fibrosis.

Chronic kidney disease (CKD) poses a significant global health dilemma, emerging from complex causes. Although our prior research has indicated that a deficiency in Reticulon-3 (RTN3) accelerates renal disease progression, a thorough examination of RTN3 on kidney function and pathology remains underexplored. To address this critical need, we generated Rtn3-null mice to study the consequences of RTN3 protein deficiency on CKD. Single-cell transcriptomic analyses were performed on 47,885 cells from the renal cortex of both healthy and Rtn3-null mice, enabling us to compare spatial architectures and expression profiles across 14 distinct cell types. Our analysis revealed that RTN3 deficiency leads to significant alterations in the spatial organization and gene expression profiles of renal cells, reflecting CKD pathology. Specifically, RTN3 deficiency was associated with Lars2 overexpression, which in turn caused mitochondrial dysfunction and increased reactive oxygen species levels. This shift induced a transition in renal epithelial cells from a functional state to a fibrogenic state, thus promoting renal fibrosis. Additionally, RTN3 deficiency was found to drive the endothelial-to-mesenchymal transition process and disrupt cell-cell communication, further exacerbating renal fibrosis. Immunohistochemistry and Western-Blot techniques were used to validate these observations, reinforcing the critical role of RTN3 in CKD pathogenesis. The deficiency of RTN3 protein in CKD leads to profound changes in cellular architecture and molecular profiles. Our work seeks to elevate the understanding of RTN3's role in CKD's narrative and position it as a promising therapeutic contender.

Case report: A novel WASHC5 variant altering mRNA splicing causes spastic paraplegia in a patient.

Background: Hereditary spastic paraplegia (HSP) is a progressive upper-motor neurodegenerative disease. Mutations in the WASHC5 gene are associated with autosomal dominant HSP, spastic paraplegia 8 (SPG8). However, due to the small number of reported cases, the exact mechanism remains unclear. Method: We report a Chinese family with HSP. The proband was referred to our hospital due to restless leg syndrome and insomnia. The preliminary clinical diagnosis of the proband was spastic paraplegia. Whole-exome sequencing (WES) and RNA splicing analysis were conducted to evaluate the genetic cause of the disease in this family. Results: A novel splice-altering variant (c.712-2A>G) in the WASHC5 gene was detected and further verified by RNA splicing analysis and Sanger sequencing. Real-time qPCR analysis showed that the expression of genes involved in the Wiskott-Aldrich syndrome protein and SCAR homolog (WASH) complex and endosomal and lysosomal systems was altered due to this variant. Conclusion: A novel heterozygous splice-altering variant (c.712-2A>G) in the WASHC5 gene was detected in a Chinese family with HSP. Our study provided data for genetic counseling to this family and offered evidence that this splicing variant in the WASHC5 gene is significant in causing HSP.

Case report: A novel mutation of RecQ-like helicase 5 in a Chinese family with early myocardial infarction, coronary artery disease, and stroke hemiplegia.

Background: Myocardial infarction (MI) is a type of severe coronary artery disease (CAD) that can lead to heart failure and sudden cardiac death. The prevalence of heart failure globally is estimated at 1%-2%, of which ∼60% of cases are the consequence of MI as the primary cause. At present, several disease-causing genes have been identified that may be responsible for MI, such as autophagy-related 16-like 1 (ATG16L1) and RecQ-like helicase 5 (RECQL5). Methods: In this study, we enrolled a Chinese family with MI, CAD, and stroke hemiplegia. Whole-exome sequencing was applied to analyze the genetic lesion of the proband. Sanger sequencing was used to validate the candidate mutation in five family members and 200 local control cohorts. Results: After data filtering, we detected a novel mutation (NM_004259: c.1247T>C/p.I416T) of RECQL5 in the proband. Sanger sequencing further validated that the novel mutation was existent in the affected individuals, including the proband's younger sister and her mother, and absent in the other healthy family members and 200 local control cohorts. Furthermore, bioinformatics analysis confirmed that the novel mutation, located in a highly evolutionarily conserved site, was predicted to be deleterious and may change the hydrophobic surface area and aliphatic index of RECQL5. Conclusion: Here, we report the second mutation (NM_004259: c.1247T>C/p.I416T) of RECQL5 underlying MI and CAD by whole-exome sequencing. Our study expanded the spectrum of RECQL5 mutations and contributed to genetic diagnosis and counseling of MI and CAD.

Increased RTN3 phenocopies nonalcoholic fatty liver disease by inhibiting the AMPK-IDH2 pathway.

Reticulon 3 (RTN3), an endoplasmic reticulum protein, is crucial in neurodegenerative and kidney diseases. However, the role of RTN3 in liver tissues has not been described. Here, we employed public datasets, patients, and several animal models to explore the role of RTN3 in nonalcoholic fatty liver disease (NAFLD). The underlying mechanisms were studied in primary hepatocytes and L02 cells in vitro. We found an increased expression of RTN3 in NAFLD patients, high-fat diet mice, and oxidized low-density lipoprotein-treated L02 cells. The RTN3 transgenic mice exhibited the phenotypes of fatty liver and lipid accumulation. Single-cell RNA sequencing analysis indicated that increased RTN3 might induce mitochondrial dysfunction. We further showed this in primary hepatocytes, the L02 cell line, and the Caenorhabditis elegans strain. Mechanistically, RTN3 regulated these events through its interactions with glucose-regulated protein 78 (GRP78), which further inhibited the adenosine 5 monophosphate-activated protein kinase (AMPK)-isocitrate dehydrogenase 2 (IDH2) pathway. In the end, knockout of RTN3 relieved fatty liver and mitochondrial dysfunction. Our study indicated that RTN3 was important in NAFLD and lipid catabolism and that an increase in RTN3 in the liver might be a risk factor for nonalcoholic steatohepatitis and NAFLD.

Postoperative clinical outcomes of patients with thymic epithelial tumors after over-3-year follow-up at a single-center.

BACKGROUND: To evaluate postoperative clinical outcomes and analyze influencing factors for patients with thymic epithelial tumors over 3 years after operation. METHODS: Patients with thymic epithelial tumors (TETs) who underwent surgical treatment in the Department of Thoracic Surgery at Beijing Hospital from January 2011 to May 2019 were retrospectively enrolled in the study. Basic patient information, clinical, pathological, and perioperative data were collected. Patients were followed up by telephone interviews and outpatient records. Statistical analyses were performed using SPSS version 26.0. RESULTS: A total of 242 patients (129 men, 113 women) with TETs were included in this study, of which 150 patients (62.0%) were combined with myasthenia gravis (MG) and 92 patients (38.0%) were not. 216 patients were successfully followed up and their complete information was available. The median follow-up period was 70.5 months (range, 2-137 months). The 3-year overall survival (OS) rate of the whole group was 93.9%, and the 5-year OS rate was 91.1%. The 3-year relapse-free survival (RFS) rate of the whole group was 92.2%, and the 5-year relapse-free survival rate was 89.8%. Multivariable COX regression analysis indicated that recurrence of thymoma was an independent risk factor for OS. Younger age, Masaoka-Koga stage III + IV, and TNM stage III + IV were independent risk factors for RFS. Multivariable COX regression analysis indicated that Masaoka-Koga staging III + IV, WHO type B + C were independent risk factors for postoperative improvement of MG. For patients with MG, the postoperative complete stable remission (CSR) rate was 30.5%. And the result of multivariable COX regression analysis showed that thymoma patients with MG with Osserman staging IIA + IIB + III + IV were not prone to achieving CSR. Compared with patients without MG, MG was more likely to develop in patients with WHO classification type B, and patients with myasthenia gravis were younger, with longer operative duration, and more likely to develop perioperative complications. CONCLUSIONS: The 5-year overall survival rate of patients with TETs was 91.1% in this study. Younger age and advanced stage were independent risk factors for RFS of patients with TETs, and recurrence of thymoma were independent risk factors for OS. In patients with MG, WHO classification type B and advanced stage were independent predictors of poor outcomes of MG treatment after thymectomy.

Case report: Whole-exome sequencing identifies a novel DES mutation (p. E434K) in a Chinese family with cardiomyopathy and sudden cardiac death.

Background: Desmin is an intermediate filament protein that plays a critical role in the stabilization of the sarcomeres and cell contacts in the cardiac intercalated disk. Mutated DES gene can cause hereditary cardiomyopathy with heterogeneous phenotypes, while the underlying molecular mechanisms requires further investigation. Methods: We described a Chinese family present with cardiomyopathy and sudden cardiac death (SCD). Whole-exome sequencing (WES) and bioinformatics strategies were employed to explore the genetic entity of this family. Results: An unknown heterozygote missense variant (c.1300G > A; p. E434K) of DES gene was identified. The mutation cosegregates in this family. The mutation was predicted as pathogenic and was absent in our 200 healthy controls. Conclusion: We identified a novel DES mutation (p. E434K) in a Chinese family with cardiomyopathy and SCD. Our study not only provided a new case for the study of the relationship between DES mutations and hereditary cardiomyopathy but also broadened the spectrum of DES mutations.

Doubly bi-allelic variants of MTHFR and MTHFD1 in a Chinese patient with hyperhomocysteinemia and failure of folic acid therapy.

Background: Hyperhomocysteinemia (HHcy) is a risk factor for thromboembolic disease. Defects in one-carbon metabolism (1-CM)-related genes, such as methylenetetrahydrofolate reductase (MTHFR), methylenetetrahydrofolate dehydrogenase, cyclohydrolase, and formyltetrahydrofolate synthetase 1 (MTHFD1), can cause HHcy and may also affect the efficacy of folic acid therapy. The details of mechanisms are yet to be further investigated. Method: We described a Chinese family with hereditary HHcy. The proband suffered from severe thromboembolic disease and experienced failure of folic acid therapy. Two sons of the proband were also diagnosed with HHcy but were sensitive to folic acid therapy. Whole-exome sequencing (WES) was conducted to evaluate the genetic lesion of this family. Results: Compound heterozygous variants (a common polymorphism, p. A222V, and a novel variant, p. C631*fs*1) of the MTHFR gene and a homozygous missense variant (p. K134R) of the MTHFD1 gene were identified in the proband. The two sons, with successful intervention, only harbored the homozygous p. A222V variant of the MTHFR gene. Conclusion: The clinical manifestations and genetic research synergistically confirmed the diagnosis of HHcy and clarified the failure of folic acid therapy in the proband caused by doubly bi-allelic variants of the MTHFR and MTHFD1 genes. Our study increased our understanding of the molecular basis of 1-CM-related gene defects on folic acid therapy in HHcy.

The first case report of CODAS syndrome in Chinese population caused by two LONP1 pathogenic mutations.

Background: CODAS syndrome (MIM 600373) is a multi-system developmental disorder characterized by cerebral, ocular, dental, auricular, and skeletal anomalies. CODAS syndrome is rare in the world and no cases have been reported in Chinese population so far. Mutations in the LONP1 gene can contribute to CODAS syndrome, while the underlying molecular mechanisms requires further investigation. Method: We described a Chinese boy who has suffered from cognition impairment, cataracts, caries, abnormal auricle and skeletal anomalies since birth. The patient's parents are non-consanguineous and healthy. Whole-exome sequencing (WES) was employed to explore the genetic entity of this family. Results: A compound heterozygous missense mutation (NM_004793: c.2009C>T/p.A670V and c.2014C>T/p.R672C) of LONP1 was identified in the patient. Considering the clinical phenotypes and genetic results, the patient was diagnosed as CODAS syndrome. Conclusion: Here we reported the first case with CODAS syndrome in Chinese population. WES identified a compound heterozygous missense mutation of LONP1 gene in the patients. Our study not only provided data for genetic counseling and clinical diagnosis to this family, but also expanded the clinical spectrum of LONP1-related CODAS syndrome.

Identification of a novel mutation in the C6 gene of a Han Chinese C6SD child with meningococcal disease.

Deficiency of the sixth complement component (C6D) is a genetic disease associated with increased susceptibility to Neisseria meningitides infection. Individuals with C6D usually present with recurrent meningococcal disease (MD). According to the patients' C6 levels, C6D is divided into complete genetic deficiency of C6 and subtotal deficiency of C6 (C6SD). The present study reported on a Han Chinese pediatric patient with MD, in whom further investigation revealed a C6SD genetic lesion. A heterozygote nonsense mutation (c.1062C>G/p.Y354*) in the C6 gene was identified by Sanger sequencing. The mutation alters the tyrosine codon at position 354 to a termination codon and results in a truncated protein. In conclusion, the genetic lesion of a pediatric patient with C6SD who was diagnosed due to having MD was investigated and a novel pathogenic mutation in the C6 gene was identified. The study confirmed the clinical diagnosis for this patient with C6SD and also expanded the spectrum of C6 mutations.

A Novel Homozygous Variant of TMEM231 in a Case With Hypoplasia of the Cerebellar Vermis and Polydactyly.

Background: Transmembrane protein 231 (TMEM231) is a component of the B9 complex that participates in the formation of the diffusion barrier between the cilia and plasma membrane. Mutations in TMEM231 gene may contribute to the Joubert syndrome (JBTS) or Meckel-Gruber syndrome (MKS). However, reports on JBTS or MKS caused by TMEM231 mutations are comparatively rare. Method: We describe a Chinese fetus with unexplained hypoplasia of the cerebellar vermis and polydactyly, detected by ultrasound imaging. The fetus was primarily diagnosed with JBTS/MKS. The parents of this fetus were non-consanguineous and healthy. Whole-exome sequencing (WES) and bioinformatics strategies were employed to explore the genetic lesion of this family. Results: An unknown missense variant (c.19C>T;p.R7W) of TMEM231 gene was detected. The variant was predicted as pathogenic and was absent in our 200 healthy controls. Conclusion: WES was employed to explore the genetic lesion of a fetus with unexplained hypoplasia of the cerebellar vermis and polydactyly. A novel variant in TMEM231 gene was identified. Our study not only provided data for genetic counseling and prenatal diagnosis to this family but also broadened the spectrum of TMEM231 mutations.

Case Report: A Novel Heterozygous Mutation of CD2AP in a Chinese Family With Proteinuria Leads to Focal Segmental Glomerulosclerosis.

Idiopathic focal segmental glomerulosclerosis (FSGS) is a relatively frequent kidney disorder that manifest clinically as proteinuria and progressive loss of renal function. Genetic factors play a dominant role in the occurrence of FSGS. CD2-associated protein (CD2AP) is an adapter molecule and is essential for the slit-diaphragm assembly and function. Mutations in the CD2AP gene can contribute to FSGS development. Here, we describe a Chinese family of four generations with unexplained proteinuria. The proband, a 12-year-old boy, was diagnosed as FSGS. Whole-exome sequencing (WES) revealed an unknown frameshift insertion mutation (p.K579Efs*7) of CD2AP gene that leads to a truncation of CD2AP protein. Bioinformatics strategies predicted that the novel mutation was pathogenic. The mutation was absent in either healthy family members or our 200 healthy controls. In summary, we used WES to explore the genetic lesion of FSGS patients and identified a novel mutation in CD2AP gene. This work broadens the mutation spectrum of CD2AP gene and provides data for genetic counseling to additional FSGS patients.

The genetic spectrum of familial hypercholesterolemia in the central south region of China.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH) is the most common and severe autosomal dominant lipid metabolism dysfunction, which causes xanthoma, atherosclerosis and coronary heart disease. Earlier studies showed that mutations in LDLR, APOB and PCSK9 cause FH. Although more than 75% of the population in Europe has been scrutinized for FH-causing mutations, the genetic diagnosis proportion among Chinese people remains very low (less than 0.5%). The aim of this study was to perform a survey and mutation detection among the Chinese population. METHODS: 219 FH patients from the central south region of China were enrolled. After extracting DNA from circulating lymphocytes, we used direct DNA sequencing to screen each exon of LDLR, APOB and PCSK9. All detected variants were predicted by Mutationtaster, Polyphen-2 and SIFT to assess their effects. RESULTS: In total, 43 mutations were identified from 158 FH patients. Among them, 11 novel mutations were found, including seven LDLR mutations, two APOB mutations and two PCSK9 mutations. Moreover, five common mutations in LDLR were detected. We geographically marked their distributions on the map of China. CONCLUSIONS: The spectrum of FH-causing mutations in the Chinese population is refined and expanded. Along with future studies, our study provides the necessary data as the foundation for the characterization of the allele frequency distribution in the Chinese population. The identification of more LDLR, APOB and PCSK9 novel mutations may expand the spectrum of FH-causing mutations and contribute to the genetic diagnosis and counseling of FH patients.

[Effects of acupuncture at different periods on circadian rhythms of locomotor activity and core body temperature in hamsters].

OBJECTIVE: To explore the time law of electroacupuncture in regulation of circadian rhythms of the organism. METHODS: Effects of electroacupuncture at "Shenshu" (BL 23) at Zi, Wu, Mao and You periods on circadian rhythms of locomotor activity and core body temperature in hamsters were observed with chronobiological research methods. RESULTS: Electroacupuncture at Wu period could decrease the amplitude of locomotor activity rhythm (P < 0.05), at Mao period could delay the peak phase of circadian rhythm and at You period could advance the peak phase of circadian rhythm (both P < 0.05); and electroacupuncture at Mao period could delay 22.36 degrees and at You period advance 39.32 degrees for the rhythm peak of the circadian rhythm of core body temperature. CONCLUSION: Acupuncture has a certain effect on circadian rhythm of locomotor activity and core body temperature.