Mutation In Exon Research Articles

Short-Term Frequently Relapsing Ischemic Strokes Followed by Rapidly Progressive Dementia in CADASIL: A Case Report and Literature Review.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary cerebral small vessel disease with slow natural progression. Ischemic stroke and cognitive impairment are its most common clinical symptoms. Here, we report a rare 50-year-old woman who had rapid disease progression with c.457C>T, p.Argl53Cys heterozygous mutation in exon 4 of NOTCH3 and discuss the possible reasons. Furthermore, we summarized the clinical and neuroimaging characteristics of 14 CADASIL patients with Arg153Cys mutation in exon 4. The proband suffered acute ischemic stroke 5 times in 5 months, followed by rapidly progressive dementia (RPD) and inability to live independently, though she didn't have vascular risk factors and had been under standardized secondary prevention therapy since the first stroke. Magnetic resonance imaging showed extensive white matter hyperintensities, numerous ischemic infarcts and microbleeds, and severe brain atrophy. Her elder brother and other patients with Arg153Cys mutation in exon 4 all did not progress so quickly. Her multiple strokes may be associated with the poor self-regulation of vessels, which may promote the occurrence of RPD. Antiplatelet and anticoagulant drugs were difficult to prevent ischemic strokes. Severe imaging findings may indicate rapid progression of CADASIL. In addition, we found that headache was a very frequent symptom in CADASIL patients with Arg153Cys mutation in exon 4, accounting for 76.9%. CADASIL can also appear to have rapid progression, as illustrated by our proband, which is worthy of clinicians' attention and intervention timely. Headache may present in a relatively higher proportion of CADASIL patients with Arg153Cys mutation in exon 4.

USP8 Mutations Associated with Cushing’s Disease Alter Protein Structure Dynamics

The adenomas in Cushing’s disease frequently exhibit mutations in exon 14, within a binding motif for the regulatory protein 14-3-3 located between the catalytic domain (DUB), responsible for ubiquitin hydrolysis, and the WW-like domain that mediates autoinhibition, resulting in constantly active USP8. The exact molecular mechanism of deubiquitinase activity disruption in Cushing’s disease remains unclear. To address this, Sanger sequencing of USP8 was performed to identify mutations in corticotropinomas. These mutations were subjected to computational screening, followed by molecular dynamics simulations to assess the structural alterations that might change the biological activity of USP8. Eight different variants of the USP8 gene were identified both within and outside the “hotspot” region. Six of these had previously been reported in Cushing’s disease, while two were detected for the first time in our patients with CD. One of the two new variants, initially classified as benign during screening, was found in the neighboring SH3 binding motif at a distance of 20 amino acids. This variant demonstrated pathogenicity patterns similar to those of known pathogenic variants. All USP8 variants identified in our patients caused conformational changes in the USP8 protein in a similar manner. The identified mutations, despite differences in annotation results—including evolutionary conservation assessments, automated predictor data, and variations in localization within exon 14—exhibit similar patterns of protein conformational change. This suggests a pathogenic effect that contributes to the development of CD.

Mutational Landscape of KIT Proto-Oncogene Coding Sequence in 62 Canine Cutaneous and Subcutaneous Mast Cell Tumors

Canine mast cell tumors (MCTs) are common skin neoplasms with varying biological behaviors. The KIT proto-oncogene plays a key role in the development of these tumors, and internal tandem duplications on exon 11 are usually associated with more aggressive behavior, increased local recurrence, and decreased survival time. However, apart from exons 8–11 and 17, there is limited understanding of the overall KIT mutational landscape in canine MCTs. This work aims to analyze the entire KIT coding sequence (21 exons) in a cohort of 62 MCTs, which included 38 cutaneous and 24 subcutaneous tumors, and potentially identify new variants. In addition to confirming previously reported activating KIT mutations in exons 8, 9, and 11, we identified new variants in exons 2, 3, 5, 16, and the 3′ untranslated region (UTR). Notably, these last variants include an amino acid change (Asp/His) in exon 16. Additionally, we confirmed a differential prevalence of KIT variants in cutaneous and subcutaneous MCTs. These findings enhance our understanding of the KIT proto-oncogene coding sequence and provide valuable information for future confirmatory studies.

Analysis of a family with hypouricemia due to type Ⅰ xanthinuria

This article reports a patient presenting with"extremely low uric acid levels in blood and urine"clinically along with reviewing relevant literature to consider a diagnosis of xanthinuria. Peripheral blood samples of the patient and her family were further collected for xanthine dehydrogenase(XDH) gene sequencing, showing that the patient had compound heterozygous mutations in exon 19:c.1995_2006del12(p.His666_Gly669del) and exon 10:c.871G>T(p.Glu291*), however no mutations were found in the gene encoding MOCOS on chromosome 18, confirming the diagnosis of hereditary xanthinuria type Ⅰ.The patient's father, son and daughter carried heterozygous mutations in exon 19:c.1995_2006del12(p.His666_Gly669del), and the mother carried heterozygous mutations in exon 10:c.871G>T(p.Glu291*).Mutations in the XDH gene cause a lack of xanthine oxidoreductase function, which hinders the production of uric acid, leading to very low or undetectable levels in blood and urine. Patients present clinically with hematuria, renal colic, urolithiasis, and even acute renal failure. Through the diagnosis and treatment of this patient and literature review, the article aims to deepen the understanding of purine metabolism and uric acid production process, and improve the clinicians' diagnosis and treatment ability of hypouricemia.

Analysis of BRCA1 Exon 2 Mutations in FFPE Tissues of Bangladeshi Bangali Females with Breast Cancer

Background: Among all breast cancers, 5 to 10% are hereditary and related to mutation of BRCA1 and BRCA2 gene. To date, extensive researches have been carried out for detection of mutations in the exon2 of BRCA1 gene. Genetic study on these two genes from formalin-fixed paraffin-embedded tissue in Bangladeshi population has not been reported so far. Objective: To identify mutation in exon2 of BRCA1 gene from formalin-fixed paraffin-embedded tissue of adult Bangladeshi Bangali female patients with breast cancer. Methods: The research was cross-sectional descriptive type of study. The study was conducted on Adult Bangladeshi Bangali female patients with breast cancer aged more than 18 years. A questionnaire was developed to record information on socio-demographic and reproductive characteristics. The data was analyzed by SPSS (Statistical package for the social sciences) version 23.0. The whole sequence of exon2 of chromosome 17 was amplified by short range PCR using the Gotaq master mix and primer sequence. The amplicons were confirmed by 2% agarose gel electrophoresis and sequencing was done by Sanger sequencer. Data analysis was performed using Chromas® software version 2.33 and Mega 7 software. The quary sequences were compared with the NCBI database. Results: Average age of the breast cancer patients was 45.46 (± 11.52) and the mean age at menarche was 12.46 (± 0.646). In this study, new mutations along with known mutations were found in exon2 of BRCA1 gene of eight adult female breast cancer patients. The mutations are insertions (C>A, C>T, T>A, G>T, G>C, T>C, A>T, C>G), deletion (C_) and single nucleotide substitution (T-C, G-A, T-G, C-G, T-A, G-C, C-A) in types. Conclusions: The aim of the research was to identify mutation in exon2 of BRCA1 gene. Eight patients have mutation in their DNA sequence revealed from formalin-fixed paraffin-embedded tissue. Further studies are required to evaluate whether these mutation contribute to breast cancer or not. Identification of known mutation along with new mutation with this small sample size emphasizes the importance of exploration the genetic makeup of Bangladeshi population to develop a database for proper screening and genetic counseling of the disease.

Lung cancer drug development: From traditional chemotherapy to targeted and immunotherapies

Abstract. Lung cancer remains one of the deadliest types of cancer in the world, with the number of deaths due to lung cancer increasing dramatically year after year. In the same period, the approach to the treatment of lung cancer has changed dramatically over the past few decades, from systemic chemotherapeutic drugs-platinum-based drugs in the beginning to a wide range of newer therapeutic approaches such as targeted therapies and immunotherapies at the present time. This article reviews the development of drug therapy for lung cancer. By comparing the differences in mechanism of action and clinical side effects between traditional chemotherapeutic drugs and targeted drugs, we aim to highlight the importance of the development of new targeted drugs and new therapeutic means. In addition, the article also analyses the development and achievements of novel drugs targeting NSCLC with MET-14 exon mutations, and looks into the possible future therapeutic strategies, but there are some research gaps in combination therapy. Through an analysis of the development of lung cancer drugs, this paper aims to provide a more comprehensive perspective to provide guidance for the development and treatment of lung cancer drugs in the future, but there are still a lot of different efficacies brought about by the combination of drugs that have not been resolved, and future research can focus on the direction of the combination of therapies.

A new immunomagnetic microfluidic device for characterizing EGFR mutations in circulating tumor cells from patients withnon-small cell lung cancer

Incorporating precision oncology into cancer management has begun to improve clinical outcomes. Accurate sampling techniques that detect molecular aberrations are crucial for effective implementation. Circulating tumor cells (CTCs), derived from primary or metastatic sites and present in the blood, are proposed as useful diagnostic tools, though their use has been limited due to their rarity, especially in early-stage cancers. This study presents a novel immunomagnetic microfluidic device that efficiently isolates CTCs for analyzing epidermal growth factor receptor (EGFR) mutations in patients with non-small cell lung cancer (NSCLC). The device was designed and laser-cut from polymethylmethacrylate. Validation experiments involved spiking PC-9 cells (an established lung cancer cell line containing GLU 746-ALA 750 deletion mutations in exon 19 of the EGFR gene) into media and isolating these cells. Exons 18 – 21 of EGFR were amplified using a polymerase chain reaction to demonstrate the device’s rapid mutation detection capability. Next-generation sequencing was used to characterize these exons in a cohort of 38 NSCLC patients, successfully isolating CTCs from all. Among these patients, 30 (79%) had EGFR mutations, with exon 19 showing the highest mutation rate (87%) and exon 21 the highest point mutation rate (23%). Our device captured CTCs effectively in <1 h, enabling mutation detection. Further studies are needed to assess the prognostic significance of these mutations, but this technology has potential applications in various solid tumors.

NCMP-01. EARLY RECURRENCE OF GLIOBLASTOMA MULTIFORM INVOLVING MULTIPLE BRAIN REGIONS ASSOCIATED WITH MUTATIONS IN EXON 4 OF ISOCITRATE DEHYDROGENASE 1 COMPLICATED BY GADOLINIUM-INDUCED ACUTE KIDNEY FAILURE: A CASE REPORT

Abstract BACKGROUND Glioblastoma multiform (GBM) remains one of the most aggressive primary brain tumors with high recurrence rates. Case presentation We present a case of a 43-year-old female, Yira, diagnosed with early recurrence of GBM involving multiple brain regions, accompanied by mutations in exon 4 of isocitrate dehydrogenase 1 (IDH1), a marker associated with poor prognosis. Additionally, this case was complicated by gadolinium-induced acute kidney failure on postoperative day 3. The patient initially presented with progressive neurological symptoms, including headache and cognitive decline. Multiplanar multiecho MRI of the brain was performed with IV contrast in orthogonal plane and revealed a moderate sized multilobulated heterogeneously and predominantly peripherally enhancing mass lesion with irregular margins and central non enhancing areas of necrosis arising from the right corona radiata, insular cortex, external capsule, lentiform nucleus, temporal, and frontal white matter with blood products. Perilesional edema was seen. Effacement of sulcal spaces. Right sylvian fissure, compression over right ventricle and midline shift of 8mm toward left side. There was dilatation of the left lateral ventricle with periventricular cerebrospinal fluid ooze. Uncal herniation was right side. On MR spectroscopy large choline, creatinine levels were seen in the lesion with reduced N-acetyl aspartate levels as compared to the normal parenchyma. Findings were suggestive of neoplastic lesion mostly high-grade glioma. Polymerase chain reaction sequencing confirmed missense mutation R132H in exon 4 of isocitrate dehydrogenase 1 gene. Despite maximal safe surgical resection, the patient developed recurrent GBM within three months, with gadolinium-based contrast agent exposure leading to acute kidney injury. CONCLUSION The combination of aggressive tumor behavior and complications from contrast agent administration highlights the challenges in managing recurrent GBM. This case underscores the importance of vigilant monitoring for complications in GBM patients, particularly those with IDH1 mutations, and the need for further research into novel therapeutic strategies.

Identification and in vivo functional analysis of a novel missense mutation in GATA3 causing hypoparathyroidism, sensorineural deafness and renal dysplasia syndrome in a Chinese family.

Hypoparathyroidism, sensorineural deafness, and renal dysplasia (HDR) syndrome is a rare autosomal dominant genetic disease associated with mutations in the GATA3 gene, which encodes GATA3 that plays essential roles in vertebrate development. This study aimed to identify and report the pathogenic mutation in GATA3 in a Chinese family diagnosed with HDR syndrome and determine its functional impacts in vivo. The clinical features of a 25-year-old male patient with HDR syndrome and his parents were collected. GATA3 gene exome sequencing and Sanger sequencing were performed on the proband and his family, respectively. Functional analyses of GATA3 were performed using bioinformatics tools and zebrafish assays to determine pathogenicity and phenotype spectrum. A novel, heterozygous, missense mutation in exon 4 of the GATA3 gene, c.863 G > A, p.Cys288Tyr, in the proband and his mother who presented the complete HDR triad, was predicted to be deleterious by in silico tools. 3D structure modeling showed that the variant caused significant structural changes. In vivo studies using a zebrafish animal model revealed the deleterious impact of the variant on the gill buds, otoliths, and pronephros. We identified a novel missense mutation, GATA3 p.Cys288Tyr, within a family with HDR syndrome and delineated it as a loss-of-function variant in vivo. This expands the spectrum of GATA3 mutations associated with HDR syndrome in the Chinese population and mimics HDR-related changes in vivo.

A novel SERPINC1 c.119G>A (p.Cys40Tyr) mutation with variable clinical expression in an Indian family.

Hereditary antithrombin (AT) deficiency due to mutations in SERPINC1 is known to be the most severe form of thrombophilia. We report three members in a family with hereditary AT deficiency with a novel mutation in exon 2 of SERPINC1, that is c.119 G>A (p.Cys40Tyr). Two brothers presented with acute pulmonary thromboembolism (PTE) at 18 and 21 years of age, whereas their 58-year-old father did not have any thrombotic episode till date. The in-silico prediction of the variant was found to be highly damaging by PolyPhen-2, SIFT and MutationTaster. Clinical exome sequencing did not show any strong coinherited thrombophilia genes, except SERPINE1 -844 G>A variant in homozygous state in the two affected brothers as compared to the father who was heterozygous for this variant. The additive effect of SERPINE1 variant in the clinical expression in two siblings cannot be ruled out, in the absence of any other known environmental triggering factors.

DAAO Mutant Sites among Different Mice Strains and Their Effects on Enzyme Activity.

Previous studies reported that D-amino acid oxidase (DAAO) activity was closely associated with neuropathic pain, cognitive characteristics of schizophrenia and so on. To determine DAAO mutant sites in different strains of mice and their effects on enzyme activity, we successfully constructed a prokaryotic expression system for heterologous expression of DAAO in vitro. There were total five nucleotide mutations distributed in exons 2, 8, 9, 10 of C57 mice. Three mutations located on exons 8 and 9 were synonymous mutations and had no variation on the encoded amino acid. The remaining two mutations in exons 2 (V64A) and 10 (R295H) were non-synonymous mutations, which might affect enzymatic activity and protein structure of mDAAO. Based on the determination of the kinetic constants and IC50 of mDAAO mutants in vitro, the differences in amino acid levels at these two sites (V64A, R295H) increased the affinity of C57 DAAO with substrate and enhanced its catalytic efficiency. Besides, the IC50 value of C57 DAAO was less than that of Balb/c and other DAAO mutants (SUN: reducted by about 11.9%; CBIO: reducted by about 26.5%), which meant that the affinity of C57 DAAO with CBIO was higher.

The p.D417N variant of TUBB4A as a possible cause of hereditary spastic paraplegia: a case report

BackgroundTubulins are dimeric proteins expressed in all eukaryotic cells, serving as the fundamental building blocks of microtubule filaments. The TUBB4A gene encodes the protein β-tubulin. Mutations of TUBB4A have been associated with two neurodegenerative diseases with very different clinical characteristics: dystonia type 4 (DYT4) and Hypomyelination with Atrophy of the Basal Ganglia and Cerebellum (H-ABC). Several cases of patients with H-ABC or unclassified leukoencephalopathy show spastic ataxia with or without leukodystrophy in association with mutations in exon 5 of TUBB4A gene.Case presentationWe report the case of a 65-year-old woman who has been complaining of progressive difficulty in walking since childhood. The neurological examination revealed, among all, a spastic gait, difficulties in standing on the toes and heels, brisk deep tendon reflexes at upper limbs, clonic patellar reflexes, brisk ankle reflexes, as well as bilateral Babinski and Hoffmann sign, brisk jaw jerk and severe lower limb spasticity. NGS studies for inherited cases of spastic paraplegia revealed a novel variant of unknown significance (VUS) (c.1249A > G, p.D417N), in TUBB4A. To the best of our knowledge, this variant has not been reported in the literature or any databases in association with these diseases.ConclusionWe report the case of a patient carrying a variant of uncertain significance (VUS) of the TUBB4A gene, showing a progressive, spastic paraparesis, supporting the extension of the phenotypic spectrum up to include spastic paraplegia.

Effects of mutation in myostatin exon 3 on growth and carcass characteristics of Savak Akkaraman sheep

The myostatin gene (MSTN) is one of the main regulatory genes involved in muscle growth and development in many animals. This study aims to determine the variations in the exon 3 region associated with MSTN expression in Savak Akkaraman sheep and analyze their relationship with growth characteristics. Molecular analyses (RLFP, Real-Time PCR and DNA sequencing) were performed using DNA and RNA isolations from 70 different sheep blood and meat samples. As a result of the study, exon 3 region analysis was performed using NgomIV, AluI, DraI, HaeIII and MspI restriction endonucleases to determine the genetic diversity in Savak Akkaraman sheep breed. Two genotypes (MM and Mm) were detected for MSTN/MspI and a monomorphic mm genotype indicating the conserved exon 3 region for MSTN/HaeIII. Additionally, four new Single Nucleotide Polymorphisms (SNPs) were detected at different positions (164th, 204th, 347th, and 441th) in the working exon region. Two of these SNPs (204th T→G: isoleucine→ methionine and 347th C→A-G: proline→glutamine-arginine) caused amino acid changes. In expression studies, it was determined that MSTN gene expression was higher in female sheep than in male sheep (p<0.05). The MM genotype (MSTN/MspI) was significantly associated with increased weight gain and MSTN expression, while TT genotype at SNP 204 and GG genotype at SNP 347 was found to be associated with meat yield and growth traits (p<0.05). As a result, the genetic differences and functional effects of the new genotypes determined in this study may shed light on breeding strategies aiming to increase meat production.

Generation of CRISPR/Cas9 modified human iPSC line with correction of heterozygous mutation in exon 6 of the CaSR gene.

The calcium-sensing receptor (CaSR) gene encodes a cell membrane G protein-coupled receptor (GPCR) which has a key role in maintaining the extracellular Ca2+ homeostasis. We aimed at correcting the compound heterozygous mutation in the 6th [c.1656delA, p.I554SfsX73] and 7th [c.2217T > A, p.C739X] exons of the CASR gene which the original patient-derived iPSC line had. The mutation is associated with neonatal severe primary hyperparathyroidism of the patient. We generated and characterized a CRISP/Cas9-edited hiPSC line with the restored sequence in the sixth exon of the CASR gene, bearing only heterozygous mutation in the 7th exon. The results showed that the new genetically modified cell line has karyotype without abnormalities, typical hiPSCs morphology, characteristic expression of pluripotency markers, and ability to develop into three germ layers, and differentiates in chondrogenic, adipogenic, osteogenic directions. This new cell line will complement the existing pool of CaSR-mutated cell lines, a valuable resource for in-depth understanding of neonatal severe primary hyperparathyroidism. This will allow further exploration of the application of pharmacological drugs in the context of personalized medicine to correct Ca-homeostasis disorders.

Optimizing Treatment Strategies for Egfr-Mutated Non-Small-Cell Lung Cancer Treated with Osimertinib: Real-World Outcomes and Insights.

Background: Osimertinib, a third-generation EGFR tyrosine kinase inhibitor (TKI), demonstrated superior efficacy over first-generation TKIs in the FLAURA trial, resulting in its approval as first-line therapy for metastatic non-small-cell lung cancer (NSCLC). However, the real-world application of these trial results requires an evaluation of sequential therapeutic strategies. Methods: This retrospective, non-interventional study utilized data from the Epidemiological Strategy and Medical Economics (ESME) platform, which includes information on patients treated for lung cancer since 2015. Out of 39,974 patients in the database, 624 patients with EGFR-mutant advanced NSCLC treated with osimertinib as first-line (L1, n = 198) or second-line (L2, n = 426) treatment after first- or second-generation TKIs (n = 1262) were identified. Patient demographics, disease characteristics, treatment strategies, and disease progression were examined. Survival analyses were performed using Kaplan-Meier estimates and Cox proportional-hazards models. Results: In the study population (n = 624), 73.4% were female, with a median age of 70 years (range 28-93). Brain metastases at the start of osimertinib treatment were observed in 282 patients. ECOG PS-2 was reported in 29.4% of patients. The T790M mutation in exon 20 was identified in 257/426 patients (60.3%) receiving osimertinib in L2. Median progression-free survival (PFS) was 12.4 months (95% CI [10.7-14.7]) for L1 and 7.4 months (95% CI [6.2-8.7]) for L2. Median overall survival (OS) from advanced diagnosis was 28.5 months (95% CI [26.3-38.7]) for osimertinib L1 and 29.9 months (95% CI [28.6-31.8]) for osimertinib L2 (HR = 0.93; 95% CI [0.75-1.16]; p = 0.50). For L1, median OS was 27.1 months (95% CI [22.0-30.2]) for patients with cerebral metastases and 38.7 months (95% CI [26.3-52.8]) for those without (HR = 0.73; 95% CI [0.48-1.11]; p = 0.15). Discussion: Patients in the real-world ESME database exhibited a poorer prognosis compared to those in the FLAURA trial. The presence of cerebral metastases at diagnosis worsens the prognosis.

Artificial intelligence can be trained to predict c-KIT-11 mutational status of canine mast cell tumors from hematoxylin and eosin-stained histological slides.

Numerous prognostic factors are currently assessed histologically and immunohistochemically in canine mast cell tumors (MCTs) to evaluate clinical behavior. In addition, polymerase chain reaction (PCR) is often performed to detect internal tandem duplication (ITD) mutations in exon 11 of the c-KIT gene (c-KIT-11-ITD) to predict the therapeutic response to tyrosine kinase inhibitors. This project aimed at training deep learning models (DLMs) to identify MCTs with c-KIT-11-ITD solely based on morphology. Hematoxylin and eosin (HE) stained slides of 368 cutaneous, subcutaneous, and mucocutaneous MCTs (195 with ITD and 173 without) were stained consecutively in 2 different laboratories and scanned with 3 different slide scanners. This resulted in 6 data sets (stain-scanner variations representing diagnostic institutions) of whole-slide images. DLMs were trained with single and mixed data sets and their performances were assessed under stain-scanner variations (domain shifts). The DLM correctly classified HE slides according to their c-KIT-11-ITD status in up to 87% of cases with a 0.90 sensitivity and a 0.83 specificity. A relevant performance drop could be observed when the stain-scanner combination of training and test data set differed. Multi-institutional data sets improved the average accuracy but did not reach the maximum accuracy of algorithms trained and tested on the same stain-scanner variant (ie, intra-institutional). In summary, DLM-based morphological examination can predict c-KIT-11-ITD with high accuracy in canine MCTs in HE slides. However, staining protocol and scanner type influence accuracy. Larger data sets of scans from different laboratories and scanners may lead to more robust DLMs to identify c-KIT mutations in HE slides.

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.

The repeated treatment of targeted therapy in the treatment of skin melanoma

Currently, patients with disseminated forms of skin melanoma have limited treatment options. The most effective treatments, according to research, are targeted drugs BRAF/MEK inhibitors when a mutation in exon 15 of the BRAF gene is detected in tumor biopsy tissue and immune synapse modulators, specifically anti-CTLA-4 and anti-PD-1 drugs. Both classes of drugs show a significant benefit in overall and progression-free survival, but convincing data on their effectiveness in second and subsequent lines of therapy are still lacking. Most often, with the progression of disseminated skin melanoma during tyrosine kinase inhibitor therapy, a dual immunotherapy combination is used. In the event of further progression, due to the limited treatment options, clinical oncologists face questions about the possibility of returning to targeted therapy, changing tyrosine kinase inhibitor drugs, or using the initial combination, and their impact on progression-free survival in choosing treatment strategies for such patients, as well as the potential use of BRAF/MEK inhibitors. Assessing the reuse of tyrosine kinase inhibitor drugs is a highly relevant issue in clinical oncology.

Correction of Griscelli Syndrome Type 2 causing mutations in the RAB27A gene with CRISPR/Cas9.

Griscelli Syndrome Type 2 (GS-2) is a rare, inherited immune deficiency caused by a mutation in the RAB27A gene. The current treatment consists of hematopoietic stem cell transplantation, but a lack of suitable donors warrants the development of alternative treatment strategies, including gene therapy. The development of mutation-specific clustered regularly interspaced palindromic repeats (CRISPR)/Cas9 gene editing technology has opened the way for custom-designed gene correction of patient-derived stem cells. In this study, we aimed to custom design CRISPR/Cas9 constructs and test their efficiency on homology-directed repair (HDR) on the correction of exon 3 and exon 7 mutations in the RAB27A gene of GS-2 patient-derived mesenchymal stem cells (MSCs) and induced pluripotent stem cells. We assessed RAB27A gene and protein expression using qRT-PCR, Western Blot, and immune fluorescence in GS-2 patient-derived MSCs and induced pluripotent stem cells (iPSCs). Guide RNAs (gRNAs) and donor DNAs were designed based on patient mutations in exon 3 and exon 7 using the CHOPCHOP online tool and transfected into GS-2 MSCs and iPSCs by electroporation. The cells were cultured for 2 days and then used for mutation analysis using DNA sequencing. MSCs and iPSCs from the GS-2 patients lacked RAB27A gene and protein expression. After gRNA and donor DNAs were designed and optimized, we found HDR efficiency with gRNA3.3 (10% efficiency) and gRNA7.3 (27% efficiency) for MSCs but lower efficiency in iPSCs (<5%). However, transfection of both MSCs and iPSCs resulted in massive cell death, loss of colony formation, and spontaneous differentiation. The use of CRISPR/Cas9 to genetically correct MSCs and iPSCs from GS-2 patients with different mutations through HDR is feasible but requires optimization of the procedure to reduce cell death and improve stem cell function before clinical application.

Editedeukaryotic translation initiation factors confer resistance against maize lethal necrosis.

Maize lethal necrosis (MLN), which is caused by maize chlorotic mottle virus along with a potyvirus, has threatened the food security of smallholders in sub-Saharan Africa. Mutations in eukaryotic translation initiation factors (eIFs), which also facilitate virus genome translation, are known to confer variable resistance against viruses. Following phylogenetic analysis, we selected two eIF4E proteins from maize as the most likely candidates to facilitate MLN infection. A knockout (KO) of each of the corresponding genes in elite but MLN-susceptible maize lines conferred only partial protection. Our inability to knockout both the genes together suggested that at least one was required for survival. When we edited (ED) the eIF4E genes in Mini Maize, however, the plants with the eif4e1-KO became highly resistant, whereas those with the eif4e2-KO remained susceptible. Neither of the causal viruses could be detected in the MLN-inoculated eif4e1-KO plants. The eIF4E2 cDNA in Mini Maize lacked the entire 4th exon, causing a 22-amino acid in-frame deletion, which shortened the protein to 198 amino acids. When we introduced mutations in the 4th exon of the eIF4E2 gene in two elite, MLN-susceptible lines pre-edited for an eif4e1-KO, we obtained as strong resistance against MLN as in eif4e1-KO Mini Maize. The MLN-inoculated lines with eif4e1-KO/eIF4E2-exon-4ED performed as well as the uninoculated wild-type lines. We demonstrate that the C-terminal 38 amino acids of eIF4E2 are dispensable for normal plant growth but are required for the multiplication of MLN viruses. Our discovery has wide applications across plant species for developing virus-resistant varieties.