Mutations In Loci Research Articles

The effect of a dominant kinase-dead Csf1r mutation associated with adult-onset leukoencephalopathy on brain development and neuropathology

Amino acid substitutions in the kinase domain of the human CSF1R protein are associated with autosomal dominant adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP). To model the human disease, we created a disease-associated mutation (Glu631Lys; E631K) in the mouse Csf1r locus. Previous analysis demonstrated that heterozygous mutation (Csf1rE631K/+) had a dominant inhibitory effect on CSF1R signaling in vitro and in vivo but did not recapitulate human disease pathology. We speculated that leukoencephalopathy in humans requires an environmental trigger and/or epistatic interaction with common neurodegenerative disease-associated alleles. Here we examine the Csf1rE631K/+ mutation impact on microglial phenotype, postnatal brain development, age-related changes in gene expression and on prion disease and experimental autoimmune encephalitis (EAE), two pathologies in which microgliosis is a prominent feature. The Csf1rE631K/+ mutation reduced microglial abundance and the expression of microglial-associated transcripts relative to wild-type controls at 12 and 43 weeks of age. There was no selective effect on homeostatic markers e.g. P2ry12, or age-related changes in gene expression in striatum and hippocampus. An epistatic interaction was demonstrated between Csf1rE631K/+ and Cx3cr1EGFP/+ genotypes leading to dysregulated microglial and neuronal gene expression in hippocampus and striatum. Heterozygous Csf1rE631K mutation reduced the microgliosis associated with both diseases. There was no significant impact on disease severity or progression in prion disease. In EAE, inflammation-associated transcripts in the hippocampus and striatum were suppressed in parallel with microglia-specific transcripts. The results support a dominant inhibitory model of CSF1R-related leukoencephalopathy and likely contributions of an environmental trigger and/or genetic background to neuropathology.

Analysis of multidrug resistance gene locus mutations and clinical significance in children with Mycoplasma pneumoniae pneumonia

To detect multidrug resistance gene locus mutations in children with Mycoplasma pneumoniae pneumonia through targeted high-throughput sequencing and to explore its clinical significance. A retrospective analysis was conducted on the clinical data of 2 899 children with Mycoplasma pneumoniae pneumonia, who underwent respiratory pathogen-targeted high-throughput sequencing, treated at Hubei Maternal and Child Health Care Hospital between January and December 2023. The patients were divided into a mutation group (n=885) and a non-mutation group (n=2 014) based on whether there was a mutation in the 23SrRNA macrolide-resistant gene of Mycoplasma pneumoniae. Multivariate logistic regression analysis was used to investigate the risk factors for multidrug resistance gene locus mutations in children with Mycoplasma pneumoniae pneumonia. Among the 2 899 children, 885 cases (30.53%) had mutations in the 23SrRNA resistance gene, including 884 cases with the A2063G mutation and 1 case with the A2064G mutation. In children with 23SrRNA resistance gene mutations, treatment with doxycycline or ofloxacin was more effective than with azithromycin or clarithromycin, and doxycycline was more effective than ofloxacin (P<0.05). The mutation rate of resistance genes in children with Mycoplasma pneumoniae pneumonia increased with age (P<0.001). Multivariate logistic regression analysis showed that increased age, extrapulmonary infection, lung consolidation, prolonged fever, prolonged hospitalization, and elevated CRP levels were risk factors for 23SrRNA gene locus mutations (P<0.05). Age, extrapulmonary infections, lung consolidation, duration of fever, length of hospitalization, and CRP levels are closely related to 23SrRNA resistance gene locus mutations. Detecting multidrug resistance gene locus mutations in children with Mycoplasma pneumoniae pneumonia can aid in early diagnosis and prediction of treatment efficacy, promoting rational clinical treatment.

7328 A case of Adrenal Calcifications in a Patient with Familial Cerebral Cavernous Malformations

Abstract Disclosure: R.I. Dorin: None. L.E. Aguirre: None. M. Bomgardner: None. Background: Familial syndromes of cerebral cavernous malformation (fCCM) having autosomal dominant inheritance and variable penetrance and expression have been linked to loss of function mutations at three genetic loci. The association of small focal adrenal calcifications with fCCM was only recently recognized in a New Mexican cohort of subjects predominately carrying the founder common Hispanic mutation in the CCM1 locus (stop codon Q455X in the Krev1 interaction trapped gene 1 [KRIT1]). We report a case of bilateral, focal adrenal calcifications in a patient affected by fCCM. Clinical Case: A 72-year-old Hispanic male with past medical history of intracranial CCM was referred for osteoporosis and hyperthyroidism due to multinodular goiter. Small focal calcifications of the adrenal glands were incidentally noted on prior imaging studies. There was no history of anticoagulant use, adrenal hemorrhage, or systemic/adrenal infection. The patient was without clinical manifestations of adrenal insufficiency, morning cortisol and plasma ACTH concentrations were normal, and exam was negative for hyperpigmentation or cutaneous vascular malformations. Brain MRI revealed the presence of over 100 parenchymal CCM lesions. A family history of CCM was reported in multiple family members, including 7/10 siblings. Conclusion: In addition to cutaneous malformations, small focal adrenal calcifications are now recognized as one of the extra-neurological manifestations of fCCM, particularly in patients harboring the common Hispanic CCM1/KRIT1 mutation. Whether adrenal calcifications are observed in fCCM patients having other mutations of KRIT1 or other genetic loci of fCCM (CCM2 or PDCD10) remains to be determined. The focal adrenal calcifications are believed to be result of dyssynchronous, subclinical hemorrhagic events related to vascular malformations in the adrenal gland. These findings implicate a role for KRIT1 in endothelial development in the adrenal gland in addition to established role in CNS, spinal cord, and skin. Our patient appeared had normal adrenocortical function, as expected for the focal nature of the adrenal lesions. Though adrenal function has not been evaluated in fCCM patients, there are no reports of primary adrenal insufficiency in fCCM in the literature. Adrenal calcifications may be considered to represent an imaging biomarker for fCCM, and fCCM should be included in the differential diagnosis of adrenal calcifications. The incidental recognition of characteristic small, focal adrenal calcifications in either bilateral or unilateral adrenal glands should prompt evaluation for fCCM.

A rare transcript homozygous variants in CLRN1(USH3A) causes Usher syndrome type 3 in a Chinese family

BackgroundUsher syndrome type 3 (USH3) is an autosomal recessive inherited disorder caused by pathogenic variants in the CLRN1 gene.ObjectTo evaluate the genotype-phenotype correlation of Usher syndrome type 3 (USH3) in a deaf-blind Chinese family of 3 generations with 2 patients.MethodsWe collected blood samples and clinical data from all of the pedigree family members. Genomic DNA was isolated from peripheral leukocytes using standard method. Targeted next generation sequencing and Sanger sequencing were performed to find the pathogenic variants in this family. Digital PCR and plasmid overexpression assay were used to verify the pathogenicity of variant sites in different transcripts.ResultsAll patients developed bilateral sensorineural hearing loss (SHL), progressive vision loss and nyctalopia. NGS of genes for Usher syndrome, deafness and retinal dystrophy identified a locus mutation in CLRN1 that caused completely different amino acid changes in different transcripts[CLRN1:c.474T > A(P.Cys158Ter) at NM_001256819.2 or c.302T > A(p.Val101Asp) at NM_174878.3], and plasmid overexpression experiments confirmed that the c.474T > A(P.Cys158Ter, NM_001256819.2) was a pathogenic variant which has never been associated with Usher syndrome in China, and the transcript of this mutation was not the version commonly found worldwide.ConclusionsThe CLRN1c.474T > A(NM_001256819.2) mutation is the causative variant in the Chinese family with USH3. The pathogenicity of different transcripts should be particularly considered in pathogenicity analysis.

KRAS and GNAS mutations in cell-free DNA and in circulating epithelial cells in patients with intraductal papillary mucinous neoplasms-an observational pilot study.

Intraductal papillary mucinous neoplasms (IPMNs) are potential precursor lesions of pancreatic cancer. We assessed the efficacy of screening for KRAS proto-oncogene, GTPase (KRAS), and GNAS complex locus (GNAS) mutations in cell-free DNA (cfDNA)-using digital droplet polymerase chain reaction (ddPCR) and circulating epithelial cell (CEC) detection-as biomarkers for risk stratification in IPMN patients. We prospectively collected plasma samples from 25 resected patients at risk of malignant progression, and 23 under clinical surveillance. Our findings revealed KRAS mutations in 10.4% and GNAS mutations in 18.8% of the overall cohort. Among resected IPMN patients, KRAS and GNAS mutation detection rates were 16.0% and 32.0%, respectively, whereas both rates were 4.0% in conservatively managed IPMN. GNAS mutations in cfDNA were significantly more prevalent in resected IPMN (P = 0.024) compared with IPMN under surveillance. No CECs were detected. The absence of KRAS and GNAS mutations could be a reliable marker for branch duct IPMN without worrisome features. The emergence of GNAS mutations could prompt enhanced imaging surveillance. Neither the presence of established worrisome features nor GNAS or KRAS mutations appear effective in identifying high-grade dysplasia among IPMN patients.

GmHs1-1 and GmqHS1 Simultaneously Contribute to the Domestication of Soybean Hard-Seededness.

Seed physical dormancy (hard-seededness) is an interesting ecological phenomenon and important agronomic trait. The loss of seed coat impermeability/hard-seededness is a key target trait during the domestication of leguminous crops which allows seeds to germinate rapidly and uniformly. In this study, we examined the mutation of quantitative trait locus (QTL) genes, GmHs1-1 and GmqHS1, in 18 wild soybean (G. soja) and 23 cultivated soybean (G. max) accessions. The sequencing results indicate that a G-to-T substitution in GmqHS1 and a C-to-T substitution in GmHs1-1 occurred in all 23 cultivated soybean accessions but not in any of the 18 wild soybean accessions. The mutations in the two genes led to increased seed coat permeability in cultivated soybean. Therefore, we provide evidence that two genes, GmHs1-1 and GmqHS1, simultaneously contribute to the domestication of hard-seededness in soybeans. This finding is of great significance for genetic analysis and improved utilization of the soybean hard-seededness trait.

A novel splice-altering TNC variant (c.5247A > T, p.Gly1749Gly) in an Chinese family with autosomal dominant non-syndromic hearing loss

BackgroundThis study aims to analyze the pathogenic gene in a Chinese family with non-syndromic hearing loss and identify a novel mutation site in the TNC gene.MethodsA five-generation Chinese family from Anhui Province, presenting with autosomal dominant non-syndromic hearing loss, was recruited for this study. By analyzing the family history, conducting clinical examinations, and performing genetic analysis, we have thoroughly investigated potential pathogenic factors in this family. The peripheral blood samples were obtained from 20 family members, and the pathogenic genes were identified through whole exome sequencing. Subsequently, the mutation of gene locus was confirmed using Sanger sequencing. The conservation of TNC mutation sites was assessed using Clustal Omega software. We utilized functional prediction software including dbscSNV_AdaBoost, dbscSNV_RandomForest, NNSplice, NetGene2, and Mutation Taster to accurately predict the pathogenicity of these mutations. Furthermore, exon deletions were validated through RT-PCR analysis.ResultsThe family exhibited autosomal dominant, progressive, post-lingual, non-syndromic hearing loss. A novel synonymous variant (c.5247A > T, p.Gly1749Gly) in TNC was identified in affected members. This variant is situated at the exon–intron junction boundary towards the end of exon 18. Notably, glycine residue at position 1749 is highly conserved across various species. Bioinformatics analysis indicates that this synonymous mutation leads to the disruption of the 5' end donor splicing site in the 18th intron of the TNC gene. Meanwhile, verification experiments have demonstrated that this synonymous mutation disrupts the splicing process of exon 18, leading to complete exon 18 skipping and direct splicing between exons 17 and 19.ConclusionThis novel splice-altering variant (c.5247A > T, p.Gly1749Gly) in exon 18 of the TNC gene disrupts normal gene splicing and causes hearing loss among HBD families.

Clinical characteristics and logistic regression analysis of macrolide-resistant Mycoplasma pneumoniae pneumonia in children.

To investigate macrolide-resistant Mycobacterium pneumoniae (MRMP) pneumonia in children and construct a logistic regression model for mutations in the Mycoplasma pneumoniae drug-resistant gene. Clinical data of 281 children were analyzed. Sequencing confirmed a mutation at the A2063G locus of the 23S rRNA gene in 227 children (A2063G group); 54 children showed no mutations (non-MRMP [NMRMP] group). We compared clinical features, laboratory tests, imaging, and bronchoscopy results and constructed a multifactorial logistic regression model to analyze risk and protective factors. The A2063G group had longer durations of fever and hospitalization before admission, a higher proportion of treatment with sodium methylprednisolone succinate (MPS)/dexamethasone, longer time to discontinue hormones, and higher probability of combined infections. Monocyte percentage was significantly higher in the A2063G group. Imaging suggested a higher incidence of infections in the right lung compared to both lungs. Univariate analysis revealed fever duration before admission, hormone dose and duration, monocyte percentage, and mixed infections as risk factors for Mycoplasma pneumoniae infection with the A2063G mutation. The logistic regression model showed that mixed infections were an independent risk factor for the A2063G locus mutation, whereas hormone dose was a protective factor. A prevalence of macrolide resistance of 80.8% among children was observed in the region. Logistic regression analysis revealed that co-infection with other respiratory pathogens is an independent risk factor for the development of resistance genes, while the use of hormone dosage acts as a protective factor.

From Headaches to Obstructive Ileus: Following the Dots

Meningioma and colorectal cancer can co-exist in the same patient and may share mutations in common genetic loci and similar cellcycle regulating proteins in comparable mechanisms of action.

Correlation analysis between driver gene mutation and clinicopathological features in lung adenocarcinoma based on real-world cumulative clinical data.

Driver genes are essential predictors of targeted therapeutic efficacy. Detecting driver gene mutations in lung adenocarcinoma (LUAD) patients can help to screen for targeted drugs and improve patient survival benefits. This study aims to investigate the mutation characterization of driver genes and their correlation with clinicopathological features in LUAD. A total of 440 LUAD patients were selected from Sir Run Run Shaw Hospital between July 2019 and September 2022. Postoperative tissue specimens were analyzed for gene mutations using next-generation sequencing technology, focusing, including epidermal growth factor receptor EGFR, ALK, ROS1, RET, KRAS, MET, BRAF, HER2, PIK3CA and NRAS. At the same time, clinicopathological data were collected and organized for multidimensional correlation analysis. Of 440 LUAD patients, driver gene mutations were not detected in 48 patients. The proportion of patients with driver gene mutations was as high as 89.09%. The top three driver genetic mutations were EGFR, KRAS, and MET. Sixty-nine types of EGFR mutations were detected and distributed in the protein tyrosine kinase catalytic domain (56, 81.16%), Furin-like cysteine-rich region (9, 13.04%), receptor binding domain (3, 4.35%), and EGFR transmembrane domain (1, 1.45%). Single gene locus mutation occurred in 343 LUAD patients, but the mutation gene types covered all tested genes. Our findings showed that EGFR mutations were more commonly observed in non-smoking and female patients (P<0.01), KRAS mutations were more prevalent in male patients and smokers (P<0.01), ROS1 mutations had larger tumor diameters (P<0.01) and RET mutations were more prevalent in smokers (P<0.05). LUAD patients exhibit diverse genetic mutations, which may co-occur simultaneously. Integrated analysis of multiple mutations is essential for accurate diagnosis and effective treatment of the disease. The use of NGS can significantly expand our understanding of gene mutations and facilitate integrated analysis of multiple gene mutations, providing critical evidence for targeted treatment methods.

Manuka combinations with nigella sativa and hydroxyurea in treating iron overload of pediatric β-thalassemia major, randomized clinical trial

Backgroundβ-thalassemia major is microcytic hypochromic anemia disorder inherited from parents, resulting from a mutation in the β-globin locus. As a result, a quantitative defective hemoglobin synthesis and relative excess in α-globin is occurred. As such, frequent blood transfusion is required, that leads to iron overload. Iron overload results in several pathological complications, including cell death, tissue injury, organ dysfunction, and liver fibrosis. The present study examined the effectiveness of nigella Sativa and manuka honey combination or manuka honey alone to the conventional therapy (Deferasirox + blood transfusion) used for preventing and managing iron overload in pediatric β-thalassemia major patients. MethodsOne hundred sixty-five patients participated in this randomized, double-blind, standard therapy-controlled, parallel-design multisite trial. The patients were randomly allocated into three groups, receiving either 500 mg nigella sativa oil combined with manuka honey lozenge (344 mg) daily or manuka honey alone plus the conventional therapy for ten treatment months. Ferritin level, serum iron, transferrin saturation, total iron binding capacity, alanine transaminase, and aspartate transaminase were determined at baseline and month 10. ResultsEventually, serum ferritin and iron were decreased significantly in the nigella sativa + manuka honey group as compared with the control group. Other clinical parameters were significantly impacted. The level of alanine transaminase and aspartate transaminase were significantly decreased in the nigella sativa plus manuka honey group compared with the control group. ConclusionResults showed that nigella sativa plus manuka honey was more effective than manuka alone or the conventional treatment alone in managing iron overload of β-thalassemia major patients.

Functional mechanism of hypoxia-like conditions mediating resistance to ferroptosis in cervical cancer cells by regulating KDM4A SUMOylation and the SLC7A11/GPX4 pathway.

The discovery of ferroptosis has unveiled new perspectives for cervical cancer (CC) management. We elucidated the functional mechanism of hypoxia-like conditions in CC cell ferroptosis resistance. CC cells were subjected to normoxia or hypoxia-like conditions, followed by erastin treatment to induce ferroptosis. The assessment of cell viability/ferroptosis resistance was performed by MTT assay/Fe2+, MDA, and glutathione measurement by colorimetry. KDM4A/SUMO1/Ubc9/SENP1 protein levels were determined by Western blot. Interaction and binding sites between KDM4A and SUMO1 were analyzed and predicted by immunofluorescence/co-immunoprecipitation and GPS-SUMO 1.0 software, with the target relationship verified by mutation experiment. SLC7A11/GPX4/H3K9me3 protein levels, and H3K9me3 level in the SLC7A11 gene promoter region were determined by RT-qPCR and Western blot/chromatin immunoprecipitation. H3H9me3/SLC7A11/GPX4 level alterations, and ferroptosis resistance after KDM4A silencing or KDM4A K471 mutation were assessed. Hypoxia-like conditions increased CC cell ferroptosis resistance and KDM4A, SUMO1, and Ubc9 protein levels, while it decreased SENP1 protein level. KDM4A and SUMO1 were co-localized in the nucleus, and hypoxia-like conditions promoted their interaction. Specifically, the K471 locus of KDM4A was the main locus for SUMO1ylation. Hypoxia-like conditions up-regulated SLC7A11 and GPX4 expression levels and decreased H3K9me3 protein level and H3K9me3 abundance in the SLC7A11 promoter region. KDM4A silencing or K471 locus mutation resulted in weakened interaction between KDM4A and SUMO1, elevated H3K9me3 levels, decreased SLC7A11 expression, ultimately, a reduced CC cell ferroptosis resistance. CoCl2-stimulated hypoxia-like conditions enhanced SUMO1 modification of KDM4A at the K471 locus specifically, repressed H3K9me3 levels, and up-regulated SLC7A11/GPX4 to enhance CC cell ferroptosis resistance.

Enhanced Molecular Response in Myeloproliferative Neoplasms with Complete JAK2V617F Inhibition.

Dunbar, Bowman, and colleagues present here a novel genetic mouse model with inducible and reversible expression of the JAK2V617F mutation in the endogenous locus. Results from this study clearly demonstrate an absolute requirement for myeloproliferative neoplasm-initiating cells for this mutation in their survival and imply that more efficacious inhibitors could be curative for these patients even in the setting of additional cooperating mutations. See related article by Dunbar et al., p. 737 (8).

Immune system parameters in patients with chronic opistorchiasis based on genetic polymorphism associated with carbohydrate and lipid metabolism disorders

A study assessing differences in the immunopathogenesis of chronic opisthorchiasis with or without genetic polymorphisms in patients associated with predisposition to type II diabetes mellitus and lipid metabolism disorders was carried out. Venous blood samples from 89 patients were collected to analyze immunological parameters and genetic polymorphisms by using pyrosequencing. In the presence of mutations affecting regulation of carbohydrate metabolism, patients with opisthorchiasis had less pronouncedly increased phagocytic activity, a lower monocyte count, higher total T-lymphocyte count, lower T-cytotoxic cell and B-lymphocyte counts, lower IgA, IgG but higher IgM concentration. This indicates a moderately compromised nonspecific resistance, imbalanced effector T- and B-immunity, but in most cases (PPARG, TCF7L2 rs12255372, CDKAL1, CDKN2A/2B, SLC30A8) aggravated humoral immune reaction to invasion particularly revealed by lower B-lymphocyte count. The presence of polymorphisms that alter lipid metabolism regulation bidirectionally affects the parameters of immune response. An increased B-lymphocyte count and other indicators of humoral immune activation to invasion, which are detected in groups with mutations in the APOE (rs429358), PCSK9, ABCA1, APOC3 rs2854117 genes, can contribute to a more effective response to sustained antigenic stimulation. Changes in the T-lymphocytes subpopulations, characteristic of opisthorchiasis invasion, are aggravated in the presence of mutations in the PCSK9, ABCA1, and APOC3 rs2854117 genes. Mutations in the genes APOC3 rs5128, LPL rs268 activate patients’ nonspecific resistance, although this effect may also be associated with exhaustion of neutrophil bactericidal reserve. In general, minor alleles of the APOE (rs429358), APOC3 rs2854117, LPL rs268, LPL rs328, PON1 rs662 genes can be considered “protective” for the immunopathogenesis of chronic opisthorchiasis. Thus, patients with chronic opisthorchiasis with different genotypes predisposing to carbohydrate and lipid metabolism disorders had significant differences in immune system parameters, which can also affect the disease course. Mutations in different loci of the PCSK9, ABCA1, APOE, APOC3, and PON1 genes have opposite effects on the analyzed immune parameters. In the presence of mutations in other genes (PPARG, TCF7L2 rs12255372, CDKAL1, CDKN2A/2B, SLC30A8, LPL), opisthorchiasis invasion leads to more pronounced alterations in immune response; mutations in the lipoprotein lipase gene may have some “protective” immune-related effect in opisthorchiasis. The effect of all studied genetic polymorphisms associated with a predisposition to developing type II diabetes mellitus was predominantly negative.

Phenotypic characterization and candidate gene analysis of a short kernel and brassinosteroid insensitive mutant from hexaploid oat (Avena sativa).

In an ethyl methanesulfonate oat (Avena sativa) mutant population we have found a mutant with striking differences to the wild-type (WT) cv. Belinda. We phenotyped the mutant and compared it to the WT. The mutant was crossed to the WT and mapping-by-sequencing was performed on a pool of F2 individuals sharing the mutant phenotype, and variants were called. The impacts of the variants on genes present in the reference genome annotation were estimated. The mutant allele frequency distribution was combined with expression data to identify which among the affected genes was likely to cause the observed phenotype. A brassinosteroid sensitivity assay was performed to validate one of the identified candidates. A literature search was performed to identify homologs of genes known to be involved in seed shape from other species. The mutant had short kernels, compact spikelets, altered plant architecture, and was found to be insensitive to brassinosteroids when compared to the WT. The segregation of WT and mutant phenotypes in the F2 population was indicative of a recessive mutation of a single locus. The causal mutation was found to be one of 123 single-nucleotide polymorphisms (SNPs) spanning the entire chromosome 3A, with further filtering narrowing this down to six candidate genes. In-depth analysis of these candidate genes and the brassinosteroid sensitivity assay suggest that a Pro303Leu substitution in AVESA.00010b.r2.3AG0419820.1 could be the causal mutation of the short kernel mutant phenotype. We identified 298 oat proteins belonging to orthogroups of previously published seed shape genes, with AVESA.00010b.r2.3AG0419820.1 being the only of these affected by a SNP in the mutant. The AVESA.00010b.r2.3AG0419820.1 candidate is functionally annotated as a GSK3/SHAGGY-like kinase with homologs in Arabidopsis, wheat, barley, rice, and maize, with several of these proteins having known mutants giving rise to brassinosteroid insensitivity and shorter seeds. The substitution in AVESA.00010b.r2.3AG0419820.1 affects a residue with a known gain-of function substitution in Arabidopsis BRASSINOSTEROID-INSENSITIVE2. We propose a gain-of-function mutation in AVESA.00010b.r2.3AG0419820.1 as the most likely cause of the observed phenotype, and name the gene AsGSK2.1. The findings presented here provide potential targets for oat breeders, and a step on the way towards understanding brassinosteroid signaling, seed shape and nutrition in oats.

Clinical characteristics and genetic analysis of six children with carnitine palmitoyltransferase 2 deficiency.

To investigate the clinical characteristic and genetic variants of children with carnitine palmitoyltransferase 2 (CPT2) deficiency. The clinical and genetic data of 6 children with CPT2 deficiency were retrospectively analyzed. The blood acylcarnitines and genetic variants were detected with tandem mass spectrometry and whole-exon gene sequencing, respectively. There were 4 males and 2 females with a mean age of 32 months (15 d-9 years) at diagnosis. One case was asymptomatic and with normal laboratory test results, 2 had delayed onset, and 3 were of infantile type. Three cases were diagnosed at neonatal screening, and 3 cases presented with clinical manifestations of fever, muscle weakness, and increased muscle enzymes. Five children presented with decreased free carnitine and elevated levels of palmitoyl and octadecenoyl carnitines. CPT2 gene variants were detected at 8 loci in 6 children (4 harboring biallelic mutations and 2 harboring single locus mutations), including 3 known variants (p.R631C, p.T589M, and p.D255G) and 5 newly reported variants (p.F352L, p.R498L, p.F434S, p.A515P, and c.153-2A>G). It was predicted by PolyPhen2 and SIFT software that c.153-2A>G and p.F352L were suspected pathogenic variants, while p.R498L, p.F434S and p.A515P were variants of unknown clinical significance. The clinical phenotypes of CPT2 deficiency are diverse. An early diagnosis can be facilitated by neonatal blood tandem mass spectrometry screening and genetic testing, and most patients have good prognosis after a timely diagnosis and treatment.

Epidemiological and genetic characteristics of norovirus in Hangzhou, China, in the postepidemic era

ObjectiveNorovirus (NoV) is an important human pathogen that can cause severe gastroenteritis in vulnerable populations. This study aimed to analyze the epidemiological and genetic characteristics of 2021–2023 NoV in Hangzhou, China. MethodsThis study enrolled patients aged 0–18 years who underwent NoV RNA detection in the hospital between January 2021 and October 2023 and analyzed the epidemiological characteristics of NoV. Polymerase chain reaction (PCR) was used to detect NoV RNA. Subtype classification and whole-genome sequencing were performed. ResultsThere was a high prevalence of NoV infection in 2023, with NoV-positive samples accounting for 63.10 % of the total number of positive samples collected during the three-year period. The prevalence was abnormally high in summer, and the number of positive samples accounted for 48.20 % of the total positive samples for the whole year, which was much greater than the level in the same period in previous years (2023, 48.20% vs 2021, 13.66% vs 2022, 15.21 %). The GⅡ.4 subtype played a leading role, followed by increased mixed infection with GⅠ.5 and GⅡ.4. Whole-genome sequencing results suggested that GII.P16-GⅡ.4 had R297H and D372N key locus mutations. The evolutionary rate was 4.29 × 10−3 for the RdRp gene and 4.84 × 10−3 for the VP1 gene. The RdRp gene and VP1 gene of NoV GII.P16-GⅡ.4 have undergone rapid population evolution during the COVID-19 epidemic. ConclusionIn the summer of 2023, an abnormally high incidence of NoV appeared in Hangzhou, China. The major epidemic strain GII.P16-GⅡ.4 showed a certain range of gene mutations and a fast evolutionary rate.

Evaluation of Fusobacterium nucleatum Enoyl-ACP Reductase (FabK) as a Narrow-Spectrum Drug Target.

Fusobacterium nucleatum, a pathobiont inhabiting the oral cavity, contributes to opportunistic diseases, such as periodontal diseases and gastrointestinal cancers, which involve microbiota imbalance. Broad-spectrum antimicrobial agents, while effective against F. nucleatum infections, can exacerbate dysbiosis. This necessitates the discovery of more targeted narrow-spectrum antimicrobial agents. We therefore investigated the potential for the fusobacterial enoyl-ACP reductase II (ENR II) isoenzyme FnFabK (C4N14_ 04250) as a narrow-spectrum drug target. ENRs catalyze the rate-limiting step in the bacterial fatty acid synthesis pathway. Bioinformatics revealed that of the four distinct bacterial ENR isoforms, F. nucleatum specifically encodes FnFabK. Genetic studies revealed that fabK was indispensable for F. nucleatum growth, as the gene could not be deleted, and silencing of its mRNA inhibited growth under the test conditions. Remarkably, exogenous fatty acids failed to rescue growth inhibition caused by the silencing of fabK. Screening of synthetic phenylimidazole analogues of a known FabK inhibitor identified an inhibitor (i.e., 681) of FnFabK enzymatic activity and F. nucleatum growth, with an IC50 of 2.1 μM (1.0 μg/mL) and a MIC of 0.4 μg/mL, respectively. Exogenous fatty acids did not attenuate the activity of 681 against F. nucleatum. Furthermore, FnFabK was confirmed as the intracellular target of 681 based on the overexpression of FnFabK shifting MICs and 681-resistant mutants having amino acid substitutions in FnFabK or mutations in other genetic loci affecting fatty acid biosynthesis. 681 had minimal activity against a range of commensal flora, and it was less active against streptococci in physiologic fatty acids. Taken together, FnFabK is an essential enzyme that is amenable to drug targeting for the discovery and development of narrow-spectrum antimicrobial agents.

A Zebrafish-Based Platform for High-Throughput Epilepsy Modeling and Drug Screening in F0.

The zebrafish model has emerged as a reference tool for phenotypic drug screening. An increasing number of molecules have been brought from bench to bedside thanks to zebrafish-based assays over the last decade. The high homology between the zebrafish and the human genomes facilitates the generation of zebrafish lines carrying loss-of-function mutations in disease-relevant genes; nonetheless, even using this alternative model, the establishment of isogenic mutant lines requires a long generation time and an elevated number of animals. In this study, we developed a zebrafish-based high-throughput platform for the generation of F0 knock-out (KO) models and the screening of neuroactive compounds. We show that the simultaneous inactivation of a reporter gene (tyrosinase) and a second gene of interest allows the phenotypic selection of F0 somatic mutants (crispants) carrying the highest rates of mutations in both loci. As a proof of principle, we targeted genes associated with neurodevelopmental disorders and we efficiently generated de facto F0 mutants in seven genes involved in childhood epilepsy. We employed a high-throughput multiparametric behavioral analysis to characterize the response of these KO models to an epileptogenic stimulus, making it possible to employ kinematic parameters to identify seizure-like events. The combination of these co-injection, screening and phenotyping methods allowed us to generate crispants recapitulating epilepsy features and to test the efficacy of compounds already during the first days post fertilization. Since the strategy can be applied to a wide range of indications, this study paves the ground for high-throughput drug discovery and promotes the use of zebrafish in personalized medicine and neurotoxicity assessment.

Relationship between polymorphisms and mutations at rs7125942 and rs3736228 of LRP5 gene and bone metabolism in postmenopausal women

ObjectiveTo analyze the relationship between the polymorphism and mutation of rs7125942 and rs3736228 locus in the low-density lipoprotein receptor-related protein 5 (LRP5) genotype and bone mineral density (BMD) in postmenopausal women in Xinjiang, China, to provide a basis for prevention and treatment of the disease.MethodsAccording to the results of dual-energy X-ray (DEXA) determination of BMD, the 136 subjects were divided into three groups: Group A: normal bone mass, Group B: osteopenia, Group C: osteoporosis. 1. Age, body, mass index (BMI), and menopause of all subjects were recorded. 2. Fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), and clinical biochemical data were determined. 3. LRP5 locus polymorphisms were determined by time-of-flight mass spectrometry.Results1. Compared with group A, the age, ALP, Cr, and BUN levels in group B and group C were increased, but UA levels were lower (P < 0.05), and Serum P was higher in the group C (P < 0.05). 2. There was no statistically significant difference in the prevalence of diabetes between the three groups (P > 0.05). 3. The ROC curves for different BMD sites such as L1, L2, L3, L4, L total, and femoral neck were 0.929, 0.955, 0.901, 0.914, 0.885, and 0.873 (P < 0.01). 4. At rs7125942 locus, there was statistically significant difference in the distribution of wild-type (CC) and mutant (CG) with the normal bone mass (NBM) group and the abnormal bone mass (ABM) group (P < 0.05). 5. At rs7125942 locus, compared with wild-type (CC), mutant (CG) had lower LDL and FPG in NBM group (P < 0.05), and lower serum ALP in the ABM group (P < 0.05). At rs3736228 locus, the BMD (Femoral neck) of mutant (CT/TT) was lower than that of wild-type (CC) in the NBM group (P < 0.05). 6. Age and menopausal years were negatively correlated with BMD of the femoral neck and L1-4 (P < 0.05), and BMI and TG were positively (P < 0.05), and the results of multiple linear regression analysis showed that age, BMI, and TG were both independent factors affecting BMD (P < 0.05).