Frameshift Research Articles

NPM1-fusion proteins promote myeloid leukemogenesis through XPO1-dependent HOX activation.

Nucleophosmin (NPM1) is a nucleolar protein and one of the most frequently mutated genes in acute myeloid leukemia (AML). In addition to the commonly detected frameshift mutations in exon12 (NPM1c), previous studies have identified NPM1 gene rearrangements leading to the expression of NPM1-fusion proteins in pediatric AML. However, whether the NPM1-fusions are indeed oncogenic and how the NPM1-fusions cause AML have been largely unknown. In this study, we investigated the subcellular localization and leukemogenic potential of two rare NPM1-fusion proteins, NPM1::MLF1 and NPM1::CCDC28A. NPM1::MLF1 is present in both the nucleus and cytoplasm and occasionally induces AML in the mouse transplantation assay. NPM1::CCDC28A is more localized to the cytoplasm, immortalizes mouse bone marrow cells in vitro and efficiently induces AML in vivo. Mechanistically, both NPM1-fusions bind to the HOX gene cluster and, like NPM1c, cause aberrant upregulation of HOX genes in cooperation with XPO1. The XPO1 inhibitor selinexor suppressed HOX activation and colony formation driven by the NPM1-fusions. NPM1::CCDC28A cells were also sensitive to menin inhibition. Thus, our study provides experimental evidence that both NPM1::MLF1 and NPM1::CCDC28A are oncogenes with functions similar to NPM1c. Inhibition of XPO1 and menin may be a promising strategy for the NPM1-rearranged AML.

Frameshift mutation spectra overlap between constitutional mismatch repair deficiency tumors and Lynch syndrome tumors.

Frameshift mutation spectra overlap between constitutional mismatch repair deficiency tumors and Lynch syndrome tumors.

MDAR: A Multiscale Features-Based Network for Remotely Measuring Human Heart Rate Utilizing Dual-Branch Architecture and Alternating Frame Shifts in Facial Videos.

Remote photoplethysmography (rPPG) refers to a non-contact technique that measures heart rate through analyzing the subtle signal changes of facial blood flow captured by video sensors. It is widely used in contactless medical monitoring, remote health management, and activity monitoring, providing a more convenient and non-invasive way to monitor heart health. However, factors such as ambient light variations, facial movements, and differences in light absorption and reflection pose challenges to deep learning-based methods. To solve these difficulties, we put forward a measurement network of heart rate based on multiscale features. In this study, we designed and implemented a dual-branch signal processing framework that combines static and dynamic features, proposing a novel and efficient method for feature fusion, enhancing the robustness and reliability of the signal. Furthermore, we proposed an alternate time-shift module to enhance the model's temporal depth. To integrate the features extracted at different scales, we utilized a multiscale feature fusion method, enabling the model to accurately capture subtle changes in blood flow. We conducted cross-validation on three public datasets: UBFC-rPPG, PURE, and MMPD. The results demonstrate that MDAR not only ensures fast inference speed but also significantly improves performance. The two main indicators, MAE and MAPE, achieved improvements of at least 30.6% and 30.2%, respectively, surpassing state-of-the-art methods. These conclusions highlight the potential advantages of MDAR for practical applications.

Germline mutations of TP53 gene can be a key factor in prostate cancer genesis

Aim: The aim of this study is to investigate whether germline alterations of exon 5 of TP53 gene could be detected in the blood of known men with prostate cancer and to assess the potential association between the genomic alteration affecting this gene and clinicopathological characteristics of the patients. Methods: Forty-eight blood samples from men diagnosed with prostate cancer were analyzed for TP53 germline mutations and confirmed by Sanger sequencing. The frequency and distribution of high-frequency mutations were analyzed according to the pathological criteria of the patients and a computational study was performed to assess the effect of new mutations. Results: The Sanger sequencing revealed that 79% of the population studied carry mutations in TP53 gene. In summary, a total of 137 mutations have been identified in this gene, out of which 115 are new mutations. Frameshift mutations were the most frequent; the mutation c.392delA was recorded in fifteen cases (31%); the mutations c.383delC and c.432delG were observed at a frequency of 12.5% and 10% respectively. The most frequent missense mutation was the variant c.502C>A (p.His168Asn) identified in eleven patients (23%). One nonsense mutation was identified in one patient and resulted in a stop codon in position 126 (tyrosine). All codons affected by these alterations are part of the DNA binding domain of the protein TP53. Conclusions: The germline mutation frequency observed in prostate cancer patients, and the new mutations recorded in TP53 gene, could be in favor of a potential association of genomic alterations in this gene and prostate cancer genesis, thereby constituting a tool, similar to other genes in the DNA repair pathway such as BRCA1 and BRCA2. This could contribute to the advancement of diagnosis and therapeutic strategies for prostate cancer.

Audio feature enhancement based on quaternion filtering and deep hashing

This paper aims to solve the problems of difficult convergence of audio model training, large data demand, and large dimensionality of storage space for audio-generated feature vectors. To this end, this paper proposes the use of quaternion Gabor filtering to suppress the background information of the spectrogram and reduce the interference of the data for the case of insufficient data alignment between audio data and image data after shifting the domain. In addition, different scales of window lengths and frame shifts are used to capture the connections between different vocal objects. To address the problem that the generated feature vectors are large dimensional, we use a deep hash module to map high-dimensional features to low-dimensional features and use a probability function to make the learned samples more consistent with the overall distribution. In the experimental evaluation, the proposed method was evaluated on the environmental sound classification dataset and the music genre classification dataset. The proposed method uses only a common backbone network and improves the accuracy of audio recognition.

A genotypic and phenotypic analysis of four unrelated Chinese patients with Pitt–Hopkins syndrome

BackgroundPitt–Hopkins syndrome (PTHS) is a rare genetic condition caused by a mutation in the transcription Factor 4 (TCF4) gene and characterized by its unique clinical presentations. At present, there is an incomplete understanding of the possible TCF4 mutations and their downstream consequences, and no reliable treatment exists for patients with PTHS. Elucidating the variations in TCF4 occurring in PTHS could lead to new treatment ideas.Case presentationWe described the clinical and genetic characteristics of four Chinese patients with PTHS. Genetic mutations related to central nervous system (CNS) disorders were identified via high-throughput sequencing. The patient’s mutations were subsequently confirmed with Sanger sequencing. Most patients had facial features typical of PTHS; however, Patient 2 demonstrated poor auricle shape. Each patient presented with differing levels of delayed development and intellectual impairment. The patients showed a splice site mutation in intron 15 of TCF4 (c.1452 + 3A > G), a frameshift mutation in exon 18 of TCF4 (c.1942delA), and two missense mutations in exon 19 of TCF4 (c. 2147C > T and c.2026A > G).ConclusionsWe discovered four new TCF4 mutations in Chinese children with PTHS. To our knowledge, the c.2026A > G and c.1942delA mutations have not yet been reported. The detection of these mutations can help accurately diagnose PTHS early, especially in patients whose clinical symptoms are not obvious. Exploring the genotype and phenotype of individuals with PTHS, will enrich our understanding and guide further research into the role of TCH4.

RNA elements required for the high efficiency of West Nile Virus-induced ribosomal frameshifting.

West Nile Virus (WNV), a member of the Flaviviridae family, requires programmed -1 ribosomal frameshifting (PRF) for translation of the viral genome. The efficiency of WNV frameshifting is among the highest observed to date. Despite structural similarities to frameshifting sites in other viruses, it remains unclear why WNV exhibits such a high frameshifting efficiency. Here we employed dual-luciferase reporter assays in multiple human cell lines to probe the RNA requirements for highly efficient frameshifting by the WNV genome. We find that both the sequence and structure of a predicted RNA pseudoknot downstream of the slippery sequence-the codons in the genome on which frameshifting occurs-are required for efficient frameshifting. We also show that multiple proposed RNA secondary structures downstream of the slippery sequence are inconsistent with efficient frameshifting. We mapped the most favorable distance between the slippery site and the pseudoknot essential for optimal frameshifting, and found the base of the pseudoknot structure likely is unfolded prior to frameshifting. Finally, we find that many mutations in the WNV slippery sequence allow efficient frameshifting, but often result in aberrant shifting into other reading frames. Mutations in the slippery sequence also support a model in which frameshifting occurs concurrent with or after translocation of the mRNA and tRNA on the ribosome. These results provide a comprehensive analysis of the molecular determinants of WNV-programmed ribosomal frameshifting and provide a foundation for the development of new antiviral strategies targeting viral gene expression.

Novel Frameshift Variant of the MYBPC3 Gene Associated with Hypertrophic Cardiomyopathy Significantly Decreases the Level of This Gene’s Transcript in the Myocardium

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease with a prevalence of 1 : 200–1 : 500 in the general population. The majority of HCM-linked pathogenic (or likely pathogenic) variants is located in eight genes encoding proteins of sarcomere, the main contractile unit of cardiomyocytes; one of these genes, MYBPC3, is the most commonly affected and usually associated with the more benign clinical course of the disease compared to other HCM-related genes. Here, we describe a novel frame shift variant NM_000256.3:c.2781_2782insCACA of the MYBPC3 gene that causes familial HCM in the heterozygous state. The proband had a progressive heart failure despite the surgical removal of left ventricular tract obstruction. Evaluation of levels of transcripts produced from the mutant allele and wild-type allele of the MYBPC3 gene in proband myocardial tissue and comparison of their total levels with ones in the control samples from patients without HCM showed a significant allele-specific reduction of mutant transcript levels. Our results expand the spectrum of known genetic variants with a proven role in the development of HCM.

Parathyroid carcinoma: molecular pathology and correlation with clinicopathologic features, a single center experience

Abstract Introduction/Objective Parathyroid Carcinomas are rare malignant neoplasms, accounting for less than 1% of primary hyperparathyroidism cases. Parathyroid carcinomas are characterized by markedly elevated levels of PTH, severe hypercalcemia and established target organ damage. The authors report the experience of a single center regarding the clinic-pathologic and genetic analysis of parathyroid carcinoma cases. Methods/Case Report The study is a retrospective review of all patients with parathyroid carcinoma that were evaluated at a tertiary oncologic center from 2001 until 2023. Results (if a Case Study enter NA) A total of nine cases (6 male and 3 female) were identified, with a mean age at diagnosis of 52 ± 16 years and a median follow-up of 16.5 years. Most patients presented with hypercalcemia (n = 7), with a mean serum calcium concentration of 13.5 mg/dl (9.6-16.5) and a mean PTH of 1123 pg/ml (<a href=“tel:276- 2500”>276-2500</a>). En bloc surgical resection was performed in 6 patients and 3 patients underwent adjuvant radiotherapy. Recurrence was observed in 4 cases (44.4%) after a median of 24 months following surgery. Negative immunohistochemical staining of parafibromin was noted in 3/4 cases of recurrence. Parathyroid carcinoma was diagnosed on the basis of finding lesions with vascular or perineural invasion, capsular penetration, and/or documented metastases. Immunohistochemical staining for parafibromin, Ki-67, and E-cadherin was performed on formalin-fixed, paraffin-embedded tissue samples. Next generation sequencing (NGS) was performed in 6/9 cases and CDC73 mutations were present in 38.5% of analyzed patients. Loss of TP53 and RB1 alleles and CCND1 amplification were other reported genetic alterations in the study cohort. Conclusion Parathyroid carcinoma is associated with a significant rate of recurrence and limited effective treatment beyond initial complete surgical resection. Inactivating CDC73 alterations which include truncating or frameshift mutations, as well as missense mutations lead to the loss of parafibromin immunoreactivity. Other molecular alterations like PTEN and PIK3CA mutations may represent potential targets for molecular therapy. An IHC panel of parafibromin, Ki-67 and E-cadherin may help to distinguish parathyroid carcinoma from other parathyroid neoplasms.

Intrinsic functional defects in B cells of patients with NFKB2 mutations.

Mutations in the human nuclear factor-κB2 gene (NFKB2) are associated with common variable immunodeficiency (CVID) or combined immunodeficiency diseases (CID), characterized by B-cell lymphopenia, hypogammaglobulinemia, and T cell dysfunction. This study investigated whether B cells with NFKB2 mutations exhibit intrinsic impairments in activation, class-switch recombination, and differentiation. We analyzed five patients from four unrelated families with CVID, each carrying a heterozygous NFKB2 mutation: P1 (C.2595_2614del, p.A867Gfs*12), P2 (C.2597G>A, p.S866N), P3 (C.2540dupT, p.R848Efs*38), and P4 and P5 (C.2570_2571insCAGCACA, p.A860Qfs*28). The patients with frameshift mutations (P1, P3, P4, and P5) exhibited truncated proteins detectable in their peripheral blood mononuclear cells, while P2 had a missense mutation. All identified mutations disrupted the processing of p100 into the active p52 form, resulting in NF-κB2 loss-of-function and IκBδ gain-of-function. Clinically, P1, P2, and P3 exhibited B-cell lymphopenia, and all five patients presented with hypogammaglobulinemia. Notably, P2 exhibited a markedly low B-cell count, associated with increased proportions of memory B and IgD-CD27- double negative B cells. In vitro experiments with naïve B cells from P1 and P4 demonstrated decreased survival, impaired activation, and reduced differentiation into CD27+IgD- cells and plasmablasts, while class switch recombination was unaffected. These findings reveal novel B cell-intrinsic functional defects in patients with NFKB2 mutations.

Knockout mutation in TaD27 enhances number of productive tillers in hexaploid wheat.

Recent advances allow the deployment of cluster regularly interspaced short palindromic repeats (CRISPR)-associated endonucleases (Cas) system for the targeted mutagenesis in the genome with accuracy and precision for trait improvement in crops. CRISPR-Cas systems have been extensively utilized to induce knockout or frameshift mutations in the targeted sequence of mostly negative regulating genes for wheat improvement. However, most of the reported work has been done in non-commercial varieties of wheat and introgression of edited alleles into breeding population comes with the penalty of unwanted linkage-drag. Wheat yield is controlled by various genes such as positive and negative regulators. The TaD27 gene is described as a negative regulator of shoot branching or tillering and involved in the biosynthesis of strigolactones. In this study, we developed Tad27 knockout mutant lines of an elite wheat cultivar that showed a twofold increase in the number of tillers and 1.8-fold increase in the number of grains per plant. Subsequently, enhancing the grain yield without any morphological penalty in the architecture of the plants. The co-transformation of regeneration enhancing growth regulator, Growth Regulating Factor 4 (GRF4) and its cofactor GRF-Interacting Factor 1 (GIF1), under single T-DNA cassette improved the regeneration efficiency up to 6% of transgenic events from mature embryos of wheat. Our results indicate that the CRISPR-mediated targeted mutagenesis confers the potential to knockout yield-related negative regulators in elite cultivars of wheat that can substantially enhance grain yield per plant and this strategy can be harnessed for the improvement of future wheat.

Ribosomal frameshifting selectively modulates the assembly, function, and pharmacological rescue of a misfolded CFTR variant

The cotranslational misfolding of the cystic fibrosis transmembrane conductance regulator chloride channel (CFTR) plays a central role in the molecular basis of CF. The misfolding of the most common CF variant (ΔF508) remodels both the translational regulation and quality control of CFTR. Nevertheless, it is unclear how the misassembly of the nascent polypeptide may directly influence the activity of the translation machinery. In this work, we identify a structural motif within the CFTR transcript that stimulates efficient -1 ribosomal frameshifting and triggers the premature termination of translation. Though this motif does not appear to impact the interactome of wild-type CFTR, silent mutations that disrupt this RNA structure alter the association of nascent ΔF508 CFTR with numerous translation and quality control proteins. Moreover, disrupting this RNA structure enhances the functional gating of the ΔF508 CFTR channel at the plasma membrane and its pharmacological rescue by the CFTR modulators contained in the CF drug Trikafta. The effects of the RNA structure on ΔF508 CFTR appear to be attenuated in the absence of the ER membrane protein complex, which was previously found to modulate ribosome collisions during "preemptive quality control" of a misfolded CFTR homolog. Together, our results reveal that ribosomal frameshifting selectively modulates the assembly, function, and pharmacological rescue of a misfolded CFTR variant. These findings suggest that interactions between the nascent chain, quality control machinery, and ribosome may dynamically modulate ribosomal frameshifting in order to tune the processivity of translation in response to cotranslational misfolding.

Germline and somatic alterations in NBN and their putative impact on the pathogenesis of malignant neoplasms

Disruption of mechanisms that maintain genome stability is an essential factor of tumor progression. Accordingly, predisposition to the development of neoplasms is often associated with germline mutations in genes involved in DNA damage detection and repair. At the same time, impairment of DNA repair systems may be a predictor of antitumor treatment efficacy while overexpression of genes involved in DNA repair is a frequent event in various types of malignancies that can lead to development of tumor cells’ resistance to chemo- and radiotherapy. NBN (nibrin) gene encodes the subunit of the MRN complex which acts as a sensor of double-strand DNA breaks and participates in their repair by homologous recombination. Germline variants in NBN which are associated with increased risk of tumor development are generally represented by frameshift mutations that lead to the synthesis of truncated protein as well as by nonsense and some missense mutations which occur in functionally significant domains. These germline mutations result in partial loss of nibrin function and in increased frequency of spontaneous and induced chromosomal aberrations in the cells of the carriers. On the contrary, amplification of NBN locus is a predominant type of somatic mutations affecting this gene, which indicates a dual role of NBN protein in tumor progression. The results of several studies demonstrate the influence of NBN expression level and its mutational status on anti-tumor drug resistance in particular types of tumor cells and on the survival rate of patients. These data indicate that an in-depth study of different variants and their functional significance is necessary since NBN status may be essential for the choice of treatment tactics for some types of tumors.

Hemoglobin Balkh, a Novel Mutation in Codon 132 of α2-Globin Gene [α132(H15) (+T) or HBA2:C.396dup (p.Val134fs)]: A Case Report and Insight into the Pathophysiology

We report a novel mutation on α2-globin gene leading to an elongated α-chain. This novel frameshift mutation was detected in a 13-year-old boy from Balkh province, Afghanistan. DNA analysis identified an insertion of thymine (T) at codon 132 [HBA2:c.396dup (p.Val134fs)]. We named the novel hemoglobin variant ‘Hemoglobin Balkh’ after the geographic location from which the patient originated. This novel variant was found in association with α3.7 kb α-globin gene deletion, suggesting a compound heterozygous state that contributes to the patient’s clinical presentation.

Identification and Characterization of Four Novel Viruses in Balclutha incisa.

Balclutha incisa (Cicadellidae: Deltocephalinae), a leafhopper prevalent in tropical and temperate regions, is notably abundant in grasses and rice. The virome of B. incisa was investigated using deep transcriptome sequencing, leading to the first identification of four viruses belonging to the families Aliusviridae, Iflaviridae, and Totiviridae in B. incisa. These viruses have been provisionally named B. incisa ollusvirus 1 (BiOV1), B. incisa ollusvirus 2 (BiOV2), B. incisa iflavirus 1 (BiIV1), and B. incisa totivirus 1 (BiTV1). The complete genome sequences of these viruses were obtained through rapid amplification of cDNA ends (RACE). BiOV1 has a linear genome of 15,125 nucleotides (nt), while BiOV2 possesses a circular genome of 14,853 nt. The BiIV1 genome, excluding the poly(A) tail, is 10,903 nt in length and encodes a single open reading frame (ORF) for a polyprotein consisting of 3194 amino acids (aa). The BiTV1 genome is 4357 nt long and contains two overlapping ORFs, with the viral RNA-dependent RNA polymerase (RdRp) translated via a -1 ribosomal frameshift. Phylogenetic and sequence identity analyses suggest that all these viruses are novel members of their respective families. This study significantly expands our understanding of the virome associated with B. incisa by reporting and characterizing these novel viruses.

7971 The Role of PDX1 In Beta Cell Response To GLP1

Abstract Disclosure: C. Bheeman: None. K. Vann: None. O. Astapova: None. Mature Onset of Diabetes of the Young Type 4 is a rare form of diabetes mellitus caused by a defect in the Pancreatic and Duodenal homeobox 1 (PDX-1) gene, which is predominantly expressed in β-cells and is an important factor in insulin gene transcription. We aim to study the impact that a PDX1 mutation (modeled after a patient) has on the beta cell response to GLP1. This was a 33-year-old nonobese man who presented to the clinic with new onset diabetes without ketosis. He was treated with insulin and metformin and his hemoglobin A1c decreased from 16% to 6.1% in six months. Other labs showed c-peptide of 8.9 ng/mL in setting of a blood glucose of 231 mg/dL, negative islet cell antibodies and glutamic acid antibodies. Of note, patient also had significant family history of diabetes. Due to high probability of MODY, genetic testing was obtained. He was found to have a heterozygous frameshift mutation in codons 228 -233 leading to a 17 base pair deletion in the PDX1 gene causing replacement of the 56 C- terminal amino acids with a shorter, missense C-terminal tail. Patient was started on dulaglutide 0.75 mg weekly but was hypoglycemic on the smallest dose so he was then switched to Semaglutide and has been maintained on less than 0.25 mg weekly. The clinical question we aim to answer was why was this patient so sensitive to GLP1 agonist activity. To study how the mutation affects response to GLP1 we are using mouse beta-TC-6 cell as they are insulin secreting, and regulated by glucose. The PDX-1 gene is highly conserved among species and the mouse PDX gene is comparable to the human gene. We used CRISPR-Cas9 to introduce the same 17 base-pair deletion into the mouse PDX-1 gene in beta-TC-6 cells. We first measured the glucose stimulated insulin secretion in control cells to examine first and second phases of insulin secretion, determining that the first phase of insulin occurs in twenty minutes and the second phase starts at about two hours. We also evaluated if these cells responded GLP-1 by increasing insulin secretion. We found that these cells respond to glucose and GLP1 in an additive manner. Insulin was measured by enzyme-linked immunosorbent assay (ELIZA). In the next phase of the experiment we aim to determine the effect of the GLP-1 in cell lines with the PDX1 deletion mutation as compared to control cell line. We will measure insulin secretion by ELISA in both mutant and the control cells treated with and without glucose and GLP1. We will measure insulin at 0 minutes and 30 minutes and insulin mRNA at 0 minutes and 6 hours to determine the first and second phases of insulin production. Our results will help guide personalized treatment for patients with MODY type 4 and improve our understanding of beta cell response to GLP1. Presentation: 6/2/2024

8415 Rapid Generation Of An In Vivo Loss-Of-Function Genetic Model Of sdhb Zebrafish: Functional And Metabolic Characterization

Abstract Disclosure: S. Parisien-La Salle: None. F. Nobilleau: None. J. Lamontagne: None. S. Éric: None. I. Bourdeau: None. Introduction: Animal research has been limited in pheochromocytomas and paragangliomas (PPGLs). Recently, Dona et al., described a sdhb mutated zebrafish model by introducing a 13 bp frameshift mutation at the sdhb exon1—intron1 boundary into the zebrafish sdhb gene that recapitulated features of PPGLs. Objective: To generate a new model of mutated sdhb zebrafish to further investigate the underlying metabolic and biochemical perturbations in vivo. Methods: We took advantage of the genetic accessibility of zebrafish embryo to generate loss-of-function model for sdhb using CRISPR/Cas9 technology. Three guide RNAs were designed and microinjected in one-cell stage zebrafish embryos to target the coding sequence of zebrafish sdhb gene. In order to control for the stress brought on by injections, we injected a group of zebrafish with Cas9 endonuclease as a control. At five days post fertilization, mutant and control zebrafish were flash frozen and sent for liquid chromatography mass spectrometry measurements of Krebs cycle metabolites and normetanephrines/metanephrines. All results were normalized to the control groups consisting of wild-type or Cas9 injected larvae. Sdhb expression was analyzed by RT-qPCR in sdhb mutants and wild-type zebrafish larvae. We also monitored survival and heart rate in sdhb mutant zebrafish, compared to wild-type and Cas9. Results: Firstly, we confirmed the significant reduction of sdhb expression in CRISPR-injected larvae compared to wild-type larvae at 5 dpf (0.0613 vs 1.000 p<0.0001). Our metabolic panel showed that succinate was up to 26 times more elevated in sdhb mutants than in wild-type fish extracts (sdhb: 26.51 p<0.0001). Lactate (sdhb: 5.27 p<0.0001), leucine (sdhb: 2.88 p<0.0001), arginine (sdhb: 1.50 p=0.0034) and HMG-CoA (sdhb: 1.36 p=0.0033) were also higher in sdhb mutants. Whereas aspartate (sdhb: 0.244 p<0.0001) and oxidized gluthiatone (sdhb: 0.64 p=0.0011) were significantly lower in sdhb mutants than in wild-types. In regards to functionality, normetanephrine and metanephrine levels were at least four folds higher in sdhb mutants than in Cas9 injected larvaes (4.06 p<0.0001 and 3.42 p<0.0001 respectively). Interestingly, this difference was more noticeable in the fish bathing medium than in larvae tissue extracts, suggesting an increased hormonal excretion (normetanephrines: 4.81 p<0.0001 and metanephrines: 9.40 p<0.0001). Finally, sdhb mutated zebrafish presented with a higher heart rate (148 vs 133 p<0.0001) and reduced lifespan (p<0.0001) when compared to the wild-type/Cas9 group. Conclusion: These findings confirm that the zebrafish is an ideal model for studying PPGLs and their associated genetic defects. Our approach allows the in vivo assessment of a large metabolic panel, opening avenues on new potential clinical metabolic biomarkers in a loss-of-function of the SDHB gene. Ref: Dona M, et al. Endocr Relat Cancer. 2021 Presentation: 6/1/2024

A novel BCHE frameshift mutation in a Chinese woman with butyrylcholinesterase deficiency: A case report and literature review.

Congenital butyrylcholinesterase deficiency (BCHED) is a rare autosomal recessive genetic disorder caused by a pathogenic mutation in the BCHE gene. Patients with BCHED may experience prolonged apnea or even death after the application of drugs such as succinylcholine. We aimed to identify the genetic basis of disease in a patient presenting with butyrylcholinesterase deficiency in order to confirm the diagnosis, expand BCHE gene mutation spectrum, and elucidate potential genotype-phenotype associations to inform management. A 51-year-old woman presented with "vague pain in the upper and middle abdomen." Her serum cholinesterase level was 211 U/L (reference value 4000-13,000 U/L). Other laboratory findings were normal. Genetic analysis revealed compound heterozygous mutations in BCHE gene, which was considered pathogenic in this case. The patient presented with low serum cholinesterase levels, which excluded common causes such as liver disease, drug toxicity, and chronic illness. Whole exon examination revealed compound heterozygous mutations in the BCHE gene; thus, the patient was diagnosed with congenital BCHED. Gastroscopy without succinylcholine or mivacurium chloride was recommended. The gastroscopy results were "gastric polyps," and gastroscopic "polypectomy" was performed. The patient was advised to avoid succinylcholine use. The patient's serum cholinesterase level was reviewed 3 months later, and the result was 215 U/L. Double heterozygous mutations are the cause of BChE deficiency of this woman in this study, including a novel mutation NM_000055.4: c.666_669del (p.Phe223Glufs*38). A review of the literature reveals considerable variation in the hotspot variants of the BCHE gene across different populations. The Chinese population displays a higher prevalence of the silent type, which is more sensitive to anesthetics such as succinylcholine. Clinical manifestations of congenital BCHED were not significant. This study avoided a potential anesthetic accident, and the novel variant enriched the BCHE gene mutation spectrum.

Activity-Based DNA-Encoded Library Screening for Selective Inhibitors of Eukaryotic Translation.

Small molecule probes exist for only ∼2% of human proteins because most lack functional binding pockets or cannot be assayed for high-throughput screening. Selective translation modulation circumvents canonical druggability and assay development constraints by using in vitro transcription-translation (IVTT) as a universal biochemical screening assay. We developed an IVTT activity assay by fusing a GFP reporter to various target gene sequences and screened the target sequences for inhibitors in microfluidic picoliter-scale droplets using a 5,348-member translation inhibitor DNA-encoded library (DEL). Screening a proof-of-concept PCSK9-GFP reporter yielded many hits; 6/7 hits inhibited PCSK9-GFP IVTT (IC50 1-20 μM), and the lead hit reduced PCSK9 levels in HepG2 cells. Preliminary selectivity was informed by counterscreening the DEL against a frameshift mutant PCSK9-GFP reporter. A plug-and-play approach to assay development and screening was demonstrated by scouting the DEL for activity using reporter genes of targets with difficult-to-assay or even unknown function (RPL27, KRASG12D, MST1, USO1). This microfluidic IVTT DEL screening platform could scale probe discovery to the human proteome and perhaps more broadly across the tree of life.

Identification of a Novel Frameshift variant of the ATRX gene: a Case Report and Review of the genotype–phenotype relationship

BackgroundX-linked intellectual disability-hypotonic facies syndrome-1 (MRXHF1) and Alpha-thalassemia X-linked intellectual disability (ATR-X) syndrome are caused by pathogenic variant in the ATRX gene, a member of the switch/sucrose non-fermentable (SWI-SNF) protein family that exhibits chromatin remodeling activity. These syndromes show a wide spectrum of clinical manifestations, such as distinctive dysmorphic features, mild-to-profound intellectual disability, motor development delay, seizures, urogenital abnormalities, and gastrointestinal disorders.Case presentation and literature reviewA 3-year-old boy from a Chinese non-consanguineous family was diagnosed with MRXHF1 by whole-exome sequencing. Comprehensive family history information was obtained. The Medline database was searched until 1st Aug 2023 for articles related to ATRX pathogenic variant. Data on gene/protein mutations and clinical symptoms were extracted. The proband showed intellectual disability, motor development delay, typical facial abnormalities, urogenital defect, behavior problems, and optical nerve dysplasia. A novel frameshift mutation c.399_400dup, (p.Leu134Cysfs*2) in the ATRX gene was the primary cause, which occurs right before the ATRXDNMT3-DNMT3L (ADD) domain of ATRX protein. Missense mutation is the most common variation type. The ADD and helicase-like domains are the most frequently affected domains. Epilepsy, congenital heart disease, urogenital defect, acoustic defect, and optical defect are more prevalent in patients with frameshift mutations compared to those with missense mutations. There are more urogenital defects with C-terminal frameshift mutations than with N-terminal frameshift mutations.ConclusionWe described a novel frameshift mutation in the ATRX gene in a patient with MRXHF1 syndrome and summarized the genotype–phenotype relationship of ATRX pathogenic variant by variation type and affected protein domain. The regulatory mechanism underlying ATRX variant requires comprehensive analysis in future studies.