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PubMed2026

Establishment of a human induced pluripotent stem cell line, KMUGMCi011-A, from a patient bearing a frameshift mutation in the KMT2D gene leading Kabuki syndrome 1.

Kabuki syndrome 1 is a rare genetic disorder typically characterized by facial abnormalities, cognitive impairment, developmental delay and organ dysfunction. It is caused by a loss-of-function mutation in the KMT2D gene. The peripheral blood mononuclear cells from a patient carrying frameshift mutation in the KMT2D gene were reprogrammed using the CytoTune-iPS2.0 Sendai Reprogramming Kit. This frameshift mutation results in a truncated protein. This established human induced pluripotent cell line will allow proper in vitro disease modelling of Kabuki syndrome 1.

Journal Article↗
PubMed2026

Phase 1 trial and biomarker analysis of Buparlisib with weekly Cisplatin and Radiotherapy in high risk locally advanced squamous cell cancer of the Head and Neck.

PURPOSE: We evaluated the pan-PI3K inhibitor buparlisib with weekly cisplatin and radiotherapy among patients with locally advanced (LA) squamous cell cancer of the head and neck (SCCHN) and tobacco history. PATIENTS AND METHODS: Patients with stage III/IV LA-SCCHN (AJCC7), ≥10 pack-year tobacco use treated with curative intent were enrolled. Patients received buparlisib during a 2-week run-in phase and during standard 70Gy of radiotherapy plus weekly cisplatin. An exploratory analysis of genomic sequencing was performed on biopsy specimens Results: Twenty-three patients were enrolled (n=17 at the MTD (buparlisib 40 mg daily, CDDP 30mg/m2/week)). Ninety-one percent (21/23) had stage IV disease. HPV was detected in 15 of 18 cases with oral/oropharyngeal disease. 5 patients suffered recurrences of whom 3 had activating mutations along the PI3K pathway. In 5 patients whose disease responded during the 2 week run-in phase with buparlisib alone, 3 of 4 with sequencing data showed loss-of-function mutations in either Tumor Necrosis Factor Receptor Associated Factor 3 (TRAF3), and/or Cylindromatosis Lysine Deubiquinatinase (CYLD). Preclinical studies with mutations in TRAF3 or CYLD via CRISPR/Cas9 knockout in HPV+SCCHN cells demonstrate that loss of TRAF3 or CYLD may sensitize SCCHN cell lines to PI3K through mechanisms other than blocking NFκb pathway. CONCLUSIONS: Buparlisib with CRT was feasible and active, though escalation to the standard weekly cisplatin dose of 40 mg/m2 was not possible. Our data suggests that TRAF3/CYLD mutant SCCHN may be susceptible to PI3K inhibition whereas PI3K pathway activation appeared to be associated with poor outcomes in this limited dataset.

Journal Article↗
PubMed2026

By comparing the effects of Lactobacillus paracasei KL1 and BK56 strains on yogurt quality, the optimal consumption time for 2 compound fermented yogurts was determined.

This study investigated the effects of 2 Lactobacillus paracasei strains, KL1 and BK56, on the physicochemical properties, microstructure, texture characteristics, and sensory quality of a compound fermented yogurt system (GK107: L. paracasei KL1, Leuconostoc mesenteroides G12S, Chr. Hansen Commercial Starter Culture; G56107: L. paracasei BK56, L. mesenteroides G12S, Chr. Hansen Commercial Starter Culture), and further integrated genomic and metabolomic analyses to infer their shelf-life and optimal consumption period. The results showed that GK107 yogurt maintained stable quality throughout the 28-d storage period (at d 28: pH 4.07; titratable acidity 93.25 °T; exopolysaccharide content 0.31 g/L; water-holding capacity 53.05%; sensory score 83), and rapidly formed a stable gel structure that persisted for an extended duration. In contrast, the quality of G56107 yogurt deteriorated during the later stage of storage (at d 28: pH 4.0; titratable acidity 98.4 °T; exopolysaccharide content 0.31 g/L; water-holding capacity 51.3%; sensory score 67). Genomic analysis revealed that, compared with the L. paracasei KL1 strain, the L. paracasei BK56 strain carried loss-of-function mutations in multiple key genes associated with flavor synthesis, polysaccharide metabolism, and proteolysis, including alsS, prtP, glpO, AWC33_RS01450, AWC33_RS00855, AWC33_RS01070, and AWC33_RS01805. These mutations may have played a role in the gradual flavor deterioration, and weak post-acidification control observed in G56107 yogurt during prolonged storage. Based on the above results, it is reasonable to suggest that GK107 yogurt is suitable for long-term storage with an optimal consumption period of 14 to 28 d, whereas G56107 yogurt is more suitable for short-term storage and recommended for consumption within the first 14 d.

Genomics↗
PubMed2026

Distinct mutational landscapes for germline and somatic cancer variants in forty tumor suppressor genes.

Germline and somatic cancer variants in tumor suppressor genes (TSGs) share loss-of-function mechanisms, but studies of a few genes (DICER1 and CEBPA) have demonstrated differences in variant consequence and location. To systematically assess whether TSGs display distinct mutational patterns, we leveraged large public genetic databases and compared 32,941 high-quality pathogenic/likely pathogenic (P/LP) germline variants in ClinVar, with 12,907 oncogenic/likely oncogenic (O/LO) somatic tumor variants from cBioPortal across 40 TSGs. Only 3,863 (9.2%) variants were shared. Eighteen TSGs showed significantly different distributions of variant occurrences by molecular consequence, replicated with non-overlapping somatic data from the COSMIC database (chi-squared tests, false discovery rate = 5%). DICER1, TP53, and SMAD4 displayed excess somatic missense events, while nine TSGs (e.g., RB1 and APC) contained excess somatic stop-gain events throughout the coding sequence. Analysis by tumor type revealed excess stop-gain events in tissues exposed to environmental mutagens with corresponding mutation signatures. For several TSGs (WT1), germline variants predispose to tumors (Wilms' tumor) distinct from the majority source of somatic data (myeloid leukemia). Germline and somatic events are also distributed unevenly across cDNA locations, with 103 regions of preferential clustering in 39 TSGs (78 somatic and 25 germline). Twenty somatic clusters contained recurring frameshifts in homopolymer runs, many in tumors with microsatellite instability. Germline clusters contain more germline-exclusive variants, some driving non-cancer phenotypes reflecting genetic pleiotropy. Altogether, germline and somatic variants of TSGs represent unique sets with substantially different patterns shaped by selection pressures from gene-specific and somatic mutational mechanisms. Characterizing these distinctions enables more accurate clinical interpretation of TSG variants.

Humans↗
PubMed2026

Generation of two induced pluripotent stem cell lines from hereditary hemorrhagic telangiectasia patients harboring ACVRL1 mutations.

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder in which dysregulated endothelial signaling drives telangiectasias and arteriovenous malformations across multiple organs. Loss-of-function variants in ACVRL1 (ALK1), a core receptor in BMP9/10 signaling, are a major genetic cause. Here we report two patient-derived induced pluripotent stem cell (iPSC) lines generated from clinically diagnosed HHT donors carrying heterozygous ACVRL1 mutations: c.129dup (p.Pro44Alafs*125) and c.430C > T (p.Arg144*). Both lines showed expected iPSC morphology, robust expression of markers of the undifferentiated iPSC state, genomic stability by LP-WGS, and tri-lineage differentiation capacity. These resources enable human cell-based studies of ACVRL1 haploinsufficiency and provide a starting point for mechanistic and therapeutic work focused on HHT vascular pathobiology.

Journal Article↗
PubMed2026

FMRP promotes gastric cancer progression via m6A-dependent stabilization of DVL2 and activation of the Wnt/PCP-JNK pathway.

BACKGROUND: N6-methyladenosine (m6A) modification has emerged as a critical regulator in gastric cancer progression. Fragile X messenger ribonucleoprotein 1 (FMRP), an RNA-binding protein with tumorigenic potential, remains poorly characterized in gastric cancer. METHODS: FMRP expression in gastric cancer was assessed through bioinformatic analyses and tissue microarray-based immunohistochemistry. Its biological functions were examined through loss-of-function experiments in vitro and in vivo. Mechanistic investigations, including RNA interaction, m6A site mutation, and RNA stability analyses, were performed to identify downstream targets and pathways regulated by FMRP. RESULTS: Bioinformatic analyses and tissue microarray-based immunohistochemistry showed that FMRP was significantly upregulated in gastric cancer tissues. FMRP depletion suppressed tumor growth and metastasis. Subsequently, Dishevelled segment polarity protein 2 (DVL2) was identified as a candidate downstream target of FMRP. DVL2 was also significantly upregulated in gastric cancer tissues, and its expression positively correlated with FMRP expression. Mechanistically, FMRP bound to DVL2 mRNA and enhanced its stability in an m6A-dependent manner. Among the candidate sites tested, mutation of 1271A attenuated FMRP-mediated regulation of DVL2 reporter activity, supporting the involvement of this site. Functionally, FMRP promoted activation of the noncanonical Wnt/planar cell polarity (PCP) signaling pathway and enhanced the proliferative, migratory, and invasive capacities of gastric cancer cells via DVL2. CONCLUSIONS: These results define FMRP as an oncogenic driver in gastric cancer that operates via the DVL2/Wnt/PCP axis. Targeting this pathway may provide a potential therapeutic strategy for gastric cancer.

Stomach Neoplasms↗
PubMed2026

Integration of multi-omics data uncovers novel germline susceptibility candidates in early-onset colorectal cancer.

Colorectal cancer (CRC) is increasingly diagnosed in individuals under 50 years of age, yet the underlying genetic predisposition remains largely unexplained, particularly in mismatch repair (MMR)-proficient cases. This study aimed to identify novel hereditary CRC susceptibility genes by integrating germline and tumour whole-exome sequencing (WES) with transcriptomic profiling across a cohort of early-onset CRC (EOCRC) patients. Tumours were categorised using Consensus Molecular Subtypes (CMS) classification and analysed for mutational signature and burden. We used a novel 'All vs One' multi-omic integration approach to identify loss-of-function rare germline variants with concordant gene expression alterations in tumour tissue. Five candidate genes (ADCY4, NOXO1, CDHR2, ARHGAP10, EEF2K) were prioritised based on this approach and potential biological relevance in CRC. These findings highlight the molecular heterogeneity of EOCRC and demonstrate the utility of multi-omic approaches in refining germline variant interpretation. Integrating tumour transcriptomics enhances gene discovery efforts and supports a more comprehensive understanding of CRC heritability in younger individuals.

Humans↗
PubMed2026

Involvement of tRNA thiolation in uORF-mediated translational regulation during Xylogenesis in Arabidopsis thaliana.

Post-transcriptional modification of tRNAs is an important mechanism for regulating translation efficiency and cellular homeostasis, yet its contribution to upstream open reading frame (uORF)-mediated translational control remains largely unexplored. In this study, we investigated the role of tRNA thiolation in thermospermine-dependent regulation of xylem development in Arabidopsis thaliana. Using a suppressor screen of the thermospermine-deficient mutant acaulis5 (acl5), which exhibits dwarfism and excessive xylem differentiation, we identified suppressor-of-acl502 (sac502) as a recessive loss-of-function allele of CTU2, a gene encoding a key enzyme in the biosynthesis of the wobble uridine modification 5-methoxycarbonylmethyl-2-thiouridine. Mutations in other components of the same modification pathway, including ROL5 and TRM9, similarly suppressed the acl5 phenotype. Translational analyses using 5' leader-GUS reporter constructs revealed that the ctu2 mutation did not enhance translation of the mRNA containing a thermospermine-responsive uORF of SAC51, but instead significantly reduced translation of that of SACL3, a member of the SAC51 family, and that of LONESOME HIGHWAY (LHW), which contains another conserved uORF in the 5' leader region. Polysome profiling further demonstrated decreased association of SACL3 and LHW mRNAs with actively translating ribosomes in ctu2. Genetic interaction analyses supported the conclusion that the suppression of excessive xylem formation in acl5 by ctu2 is attributable to reduced LHW activity. In addition, ctu2 mutants displayed increased sensitivity to exogenous thermospermine, resembling the response of lhw mutants. Together, our results reveal that tRNA thiolation contributes to uORF-mediated translational regulation of key developmental regulators and identify tRNA modification as an important regulatory layer controlling vascular development.

Arabidopsis↗
PubMed2026

Unveiling the power of TIIC: A prognostic tool for esophageal adenocarcinoma.

BACKGROUND: Esophageal adenocarcinoma (EAC) remains a lethal malignancy with limited prognostic tools for guiding immunotherapy. Tumor-infiltrating immune cells (TIICs) play a critical role in EAC prognosis and treatment response. METHODS: We integrated single-cell RNA sequencing and bulk transcriptome data from TCGA and GEO databases. TIIC-specific RNAs were identified via tissue specificity index calculation combined with machine learning feature selection. Twenty machine learning algorithms were benchmarked to construct an optimal TIIC signature score (TIIC-Score) based on the comprehensive C-index. Immunotherapy response, genomic mutation, and copy number variation were analyzed. Summary-data-based Mendelian randomization (SMR) and two-sample Mendelian randomization (MR) were performed to explore genetic associations. Core prognostic TIIC-related genes were functionally validated in esophageal cancer cell lines through loss-of-function assays. RESULTS: The TIIC-Score demonstrated robust prognostic value for 1-, 2-, and 3-year overall survival across multiple cohorts, outperforming 22 published models. High TIIC-Score was associated with poor survival and increased chromosomal instability. Mutation profiling revealed high frequencies of TP53 (78.2%), TTN (48.7%), and SYNE1 (30.8%). MR analysis identified a significant association between gastro-oesophageal reflux and EAC risk at SNP rs8130507. Functionally, CCNI was upregulated in esophageal cancer cells, and its knockdown suppressed malignant phenotypes while promoting apoptosis, supporting its pro-tumorigenic role. CONCLUSION: The TIIC-Score provides a novel prognostic framework for EAC that effectively stratifies patient risk and may help identify individuals most likely to benefit from immunotherapy.

Esophageal adenocarcinoma↗
PubMed2026

OsMYB8-OsARF12/25 module fine-tunes tiller angle via auxin signaling pathway in rice.

Tiller angle is a critical determinant of rice plant architecture and significantly impacts grain yield by influencing planting density and photosynthetic efficiency. Although auxin signaling is known to affect tiller angle in rice, the detailed regulatory networks remain largely unknown. In this study, we identify OsMYB8, an R2R3-MYB transcription factor, as a positive regulator of rice tiller angle. Functional analyses revealed that loss-of-function mutants of OsMYB8 exhibited reduced tiller angles and a more compact architecture, while overexpression of OsMYB8 resulted in more expanded tiller angles. Further investigations found that OsMYB8 might negatively regulate the shoot gravitropic response by disrupting asymmetric auxin distribution. At the molecular level, OsMYB8 directly binds to the promoters of 2 auxin response factors, OsARF12 and OsARF25, and represses their transcription. Genetic analyses confirmed that OsMYB8 acts upstream of OsARF12 and OsARF25 in regulating rice tiller angle. Our finding elucidates a previously uncharacterized OsMYB8-OsARF12/25 transcriptional module that fine-tunes auxin signaling to regulate tiller angle in rice, and offers valuable genetic targets for the optimization of rice architecture and yield potential.

Oryza↗
PubMed2026

Epigenetic Repression of TP53 Transcription Underlies Cancer Cell Persistence for Carboplatin Resistance in Non-Small Cell Lung Cancer.

While chemoresistance in non-small cell lung cancer (NSCLC) cells has historically been attributed to permanent genetic mutations, emerging evidence highlights the role of nongenetic transcriptional plasticity and 'drug-tolerant persister' cells. To systematically map these epigenetic vulnerabilities, we utilized a genome-wide CRISPR interference library to screen wild-type TP53 NSCLC (A549) cells under carboplatin selection. Using the DrugZ algorithm and subsequent pathway enrichment analyses, this screen revealed that transcriptional suppression of interstrand crosslink DNA repair networks, including the Fanconi anemia pathway, markedly sensitized cells to carboplatin. Unexpectedly, transcriptional silencing of TP53 and its downstream target CDKN1A emerged as the strongest drivers of resistance, enabling cells to bypass therapy-induced senescence and maintain their proliferative potential later. To validate these findings in a clinically relevant context, we established a chronic carboplatin-resistant cell model (A549CarboR cells). A549CarboR exhibited a reduction in TP53 transcripts, along with decreased H3K27 acetylation and increased DNA hypermethylation on its promoter. Epigenetic remodeling using the DNA methyltransferase inhibitor (DNMTi) was associated with unblocking TP53 transcription, restored p53 signaling, and resensitization of resistant cells to carboplatin. Conversely, histone deacetylase inhibitors induced CDKN1A transcription to bypass TP53, indicating distinct epigenetic circuits. Collectively, the results demonstrate for the first time that TP53 expression is dynamically regulated at the transcriptional level through promoter methylation related to the drug tolerance. These insights emphasize that epigenetic silencing, rather than exclusive genetic loss-of-function, contribute to platinum resistance and underscore the therapeutic potential of pairing platinum regimens with DNMTi to target the transcriptomic plasticity of persistent cancer cell populations.

CRISPR interference screening↗
PubMed2026

Multi-Omics Integration Identifies a Five-Gene Metabolic Signature With Experimental Validation in Clear Cell Renal Cell Carcinoma.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is hallmarked by profound metabolic reprogramming; however, its intricate crosstalk with the tumor immune microenvironment (TIME) and its clinical ramifications remain inadequately elucidated. This study aims to systematically decipher the metabolic-immune interplay in ccRCC through multi-omics integration, with the goal of identifying robust prognostic biomarkers and actionable therapeutic vulnerabilities. AIMS: This study aims to systematically decipher the metabolic-immune interplay in clear cell renal cell carcinoma (ccRCC) through multi‑omics integration, and to identify robust prognostic biomarkers and actionable therapeutic vulnerabilities that can inform precision risk stratification and individualized treatment strategies. METHODS: We integrated bulk transcriptomic, genomic, and clinical data from multiple ccRCC cohorts. Differential expression and functional enrichment analyses were performed to characterize metabolic pathway alterations. Mendelian randomization (MR) was employed to infer causal relationships between metabolic disorders and ccRCC risk. A machine learning-based prognostic framework, incorporating SHAP (SHapley Additive exPlanations) for feature interpretability, was constructed and rigorously validated. TIME heterogeneity was dissected using deconvolution algorithms, while drug sensitivity, tumor mutation burden (TMB), and TIDE scores were utilized to assess therapeutic responses and immune evasion. Candidate gene function was evaluated through in vitro gain- and loss-of-function assays, with expression validated via TCGA, HPA, western blot, and qRT-PCR. RESULTS: Enrichment analysis identified coordinated dysregulation in lipid metabolism, energy homeostasis, and hypoxia response pathways. MR analysis confirmed lipid metabolism disorders as a causal risk factor for ccRCC. Our machine-learning model, centered on five core SHAP-identified features (SUCLA2, ACAT1, PC, SUCLG1, and HMGCS2), demonstrated superior predictive accuracy over conventional clinical staging. Immune profiling unveiled dichotomous TIME states: the low-risk group retained active immune surveillance, whereas the high-risk group was enriched with immunosuppressive subsets. Drug sensitivity screening pinpointed LY2109761 and carmustine as high-risk-specific candidate agents. Furthermore, TMB and TIDE analyses stratified high-risk patients displaying genomic instability and immune evasion phenotypes. Functionally, SUCLA2 knockdown significantly enhanced ccRCC cell proliferation and invasion, while its overexpression suppressed these malignant phenotypes, corroborating its tumor-suppressive role. Expression patterns of the hub genes were consistently validated across multi-level datasets and experimental assays. CONCLUSION: This study establishes a precision oncology framework for ccRCC by functionally linking metabolic biomarkers, immunophenotypes, and stratified therapeutic strategies. Importantly, we identify SUCLA2 as a potential functional tumor suppressor and a promising target for further mechanistic and translational investigation.

Humans↗
PubMed2026

Monogenic ALB Variants as Determinants of Severe Hypercholesterolemia: A Population-Based Cohort Study.

BACKGROUND: Hypoalbuminemia is associated with several risk factors for myocardial infarction, including hypercholesterolemia, liver disease, kidney disease, and diabetes. Homozygosity of loss-of-function (LoF) variants in the ALB gene, which encodes albumin, is a known cause of congenital hypoalbuminemia. Studies have also shown that heterozygous ALB LoF variants are associated with increases in low-density lipoprotein cholesterol (LDL-C), comparable to those seen in familial hypercholesterolemia. OBJECTIVES: This study examined the effect of ALB LoF variants and other causes of low albumin on LDL-C levels in 2 population biobanks. METHODS: This study used data from 2 large cohorts with linked electronic health record and genetic information: Geisinger's MyCode Community Health Initiative, a health care population based in Pennsylvania, USA; and the National Institutes of Health All of Us Research Program, a nationwide epidemiologic cohort. LDL-C values were adjusted for lipid-lowering medication use. Myocardial infarction diagnoses were extracted from electronic health records using International Classification of Diseases codes. A polygenic score for serum albumin was calculated for participants of European ancestry. Linear regression models were used to estimate associations, and results were meta-analyzed across cohorts using fixed-effects models. RESULTS: Among 155,530 MyCode and 405,701 All of Us adult participants, 77 individuals (1 of 7,289) carried an ALB LoF variant. Among noncarriers, a 1 g/dL decrease in serum albumin was associated with a 10.9 mg/dL (95% CI:, 10.4-11.4) decrease in LDL-C. In contrast, ALB LoF variants were associated with a 0.69 g/dL (95% CI: 0.60-0.78) reduction in serum albumin and a 38.3 mg/dL (95% CI: 28.2-48.5) increase in LDL-C. Paradoxically, whereas monogenic determinants of hypoalbuminemia were associated with increased LDL-C, polygenic determinants of lower albumin were associated with a 0.22 mg/dL (95% CI: 0.17-0.26) decrease in LDL-C per decile. CONCLUSIONS: ALB LoF variants represent a previously underrecognized monogenic cause of elevated LDL-C, with effect sizes slightly less than canonical familial hypercholesterolemia variants. The divergent effects of ALB-mediated vs polygenic or physiological reductions in albumin on LDL-C suggest distinct underlying mechanisms.

Humans↗
PubMed2026

Gastrointestinal involvement in Ehlers-Danlos syndrome classical-like type 2 associated with a novel AEBP1 splice-site variant.

Ehlers-Danlos syndrome classical-like type 2 (clEDS2) is a rare autosomal recessive connective tissue disorder caused by biallelic loss-of-function variants in the gene encoding adipocyte enhancer-binding protein 1 (AEBP1). While cutaneous and skeletal manifestations are commonly observed, gastrointestinal complications, including bowel rupture, have been reported only rarely, and their histopathological basis remains poorly characterized. Here, we report findings of molecular investigations, gastrointestinal histopathological evaluation, and long-term clinical follow-up in the 16th reported patient with AEBP1-related clEDS2, complicated by spontaneous bowel perforation. A homozygous AEBP1 splice-site variant (NM_001129.5:c.1401-2 A > G) was identified by a custom next-generation sequencing-based panel analysis for hereditary connective tissue disorders. Transcript-level analysis by reverse transcription-polymerase chain reaction and Sanger sequencing demonstrated complete skipping of exon 12, resulting in a frameshift and predicted loss of function. Clinically, the patient experienced postoperative perforation in the sigmoid colon shortly after rectal cancer surgery, followed nearly 20 years later by spontaneous small intestinal perforation. Histopathological examination of the affected colonic tissue demonstrated mildly widened intermuscular spaces without other overt structural abnormalities. Notably, repeated upper and lower gastrointestinal endoscopic procedures were performed during long-term oncological surveillance without procedure-related bowel perforation. This observation could offer an opportunity to learn about gastrointestinal involvement in AEBP1-related clEDS2 and suggests that its gastrointestinal manifestations may differ in clinical context from those typically associated with vascular Ehlers-Danlos syndrome, warranting further investigation as additional cases are accumulated.

Humans↗
PubMed2026

Mapping genetic modifiers of epimutation rates identifies VIM2/4 as dosage-sensitive negative regulators of CG methylation maintenance.

Spontaneous epimutations are stochastic gains and losses of cytosine methylation that arise from imperfect maintenance across cell divisions. At CG sites, such epimutations can be inherited across generations in plants and constitute a major source of CG methylation (mCG) diversity. However, why the fidelity of mCG inheritance varies among genotypes, and how this variation relates to steady-state mCG levels, remains poorly understood. Here we tracked DNA methylation over 10 generations in ~400 mutation-accumulation lines derived from ~70 Arabidopsis thaliana Ler × Cvi recombinant inbred founders. By treating methylation gain and loss rates as quantitative molecular traits, we mapped a major-effect locus to a Cvi-derived deletion between VARIANT IN METHYLATION (VIM)2 and VIM4, two key components of the METHYLTRANSFERASE 1-dependent mCG maintenance pathway. Lines carrying this deletion showed elevated VIM2/4 (VIM2 and VIM4) expression, a rapid shift of genome-wide mCG towards a lower steady state and reduced fidelity of methylation inheritance across generations. Complementary overexpression and loss-of-function experiments identify VIM2/4 as dosage-sensitive negative regulators of mCG maintenance, in contrast to the canonical positive role of VIM-family proteins in mCG. Together, our results support a punctuated-equilibrium model of DNA methylome evolution, in which naturally segregating modifiers of mCG homeostasis can produce abrupt shifts in methylation state and alter the rate at which heritable epigenetic variation accumulates in plant genomes.

Journal Article↗
PubMed2026

Automated patch clamp data improve variant classification and penetrance stratification for SCN5A-Brugada syndrome.

BACKGROUND AND AIMS: Brugada Syndrome (BrS) is an inherited arrhythmia disorder that causes an elevated risk of sudden cardiac death. Approximately 20% of patients with BrS have rare variants in SCN5A, which encodes the cardiac sodium channel NaV1.5. Genetic workup of BrS is often complicated by SCN5A variants of uncertain significance (VUS) and/or incomplete penetrance. This study deployed an SCN5A-BrS functional assay at cohort scale to facilitate the implementation of genetic and precision medicine. METHODS: All 252 missense and in-frame insertion/deletion SCN5A variants from a previously published large cohort of BrS cases (n = 3335 patients) were analysed using a calibrated high-throughput automated patch-clamp (APC) assay. Variant functional Z-scores were assigned evidence levels ranging from BS3_moderate (normal function) to PS3_strong (loss-of-function), as defined by American College of Medical Genetics and Genomics criteria. Functional evidence was combined with population frequency, hotspot, case counts, protein-length changes, and in silico predictions. Odds ratios of BrS case-control enrichment and penetrance for BrS were calculated from variant frequencies in the BrS cohort and in gnomAD. RESULTS: Most variants (146/252) were functionally abnormal (Z ≤ -2), with 100 having severe loss-of-function (Z ≤ -4). Functional evidence enabled the reclassification of 110 of 225 VUS; 104 to likely pathogenic and 6 to likely benign. SCN5A variants with loss-of-function were mainly localized to the transmembrane domains, especially the regions comprising the central pore. SCN5A variant penetrance was proportional to the severity of loss-of-function; variants with Z ≤ -6 had penetrance of 24.5% (15.9%-37.7% CI) and an odds ratio of 501 for BrS. CONCLUSIONS: This cohort-scale APC dataset stratifies SCN5A variants found in BrS patients into normal function 'bystander' variants that have a low risk of BrS and loss-of-function variants that have a high risk for BrS. Functional data can be integrated with other criteria to reclassify a substantial fraction of VUS. The dataset helps clarify the SCN5A-BrS relationship and will improve the diagnosis and clinical management of BrS probands and their families.

Humans↗
PubMed2026

Establishment of a Common Marmoset Lineage Carrying a Frameshift Mutation in SETD1A, a Schizophrenia Risk Gene.

Appropriate histone modifications are essential for maintaining functional chromatin structure and gene expression, and dysfunction of their regulators has been linked to a variety of diseases. Among these modifications, trimethylation of lysine 4 on histone H3 (H3K4me3) is a well-characterized epigenetic mark enriched at transcription start sites of actively transcribed genes. H3K4me3 regulates gene transcription by recruiting transcription factors, facilitating chromatin accessibility, and preventing DNA methylation. In mammals, methylation of H3K4 is catalyzed by a family of histone methyltransferases including SET domain containing 1A (SETD1A), which is primarily responsible for genome-wide deposition of H3K4me2/3. Loss-of-function variants in SETD1A, highlighting its critical role in brain development and cognitive function, are strongly associated with schizophrenia (SCZ) and other neurodevelopmental disorders, but the underlying mechanisms remain largely unclear. To better understand the epigenetic and neurobiological consequences of SETD1A dysfunction, non-human primate models can serve as a useful tool because of their close evolutionary relationship to humans and highly developed cognitive abilities. In this study, we established a genetically engineered common marmoset (Callithrix jacchus) lineage carrying a frameshift mutation in SETD1A, which is, to the best of our knowledge, the first non-human primate lineage carrying a mutation in an epigenetic regulatory gene associated with SCZ, and confirmed germline transmission of the mutant allele. In a comparison between fibroblasts derived from one SETD1A mutant and one wild-type marmoset, the mutant showed a lower SETD1A protein level, modest differences in H3K4me3 deposition, and broader differences in gene expression profiles. Although these molecular observations require validation using additional biological replicates, the establishment of this SETD1A mutant marmoset lineage provides a valuable platform for bridging molecular mechanisms with primate neurobiology and for investigating the role of epigenetic regulation in the pathophysiology of neuropsychiatric and neurodevelopmental disorders.

Animals↗
PubMed2026

Identification of biallelic loss-of-function PREP variants in three individuals with syndromic intellectual disability.

BACKGROUND: Neurodevelopmental disorders are one of the most prevalent reasons for genetic testing in childhood. Despite the identification of over 1950 associated genes, many proposed candidate genes lack convincing gene-disease validity. The gene PREP encodes the broadly expressed prolyl endopeptidase whose exact function remains largely unknown. A homozygous PREP variant has been reported once as a candidate gene in two siblings with intellectual disability but no functional studies were conducted. METHODS: Exome and trio genome sequencing were performed in two unrelated families as part of larger cohorts. Segregation analysis, RNA sequencing and immunoblots were performed to further examine the pathogenicity of detected PREP variants. RESULTS: We report three individuals from two unrelated families who presented with intellectual disability, behavioural abnormalities, strabismus, generalised muscular hypotonia, dysmorphic facial features and epilepsy. Exome and genome sequencing identified two different homozygous rare PREP variants: c.1570_1573dup, p.(Asn525Thrfs*5) and c.1839-2A>G, p.?. RNA sequencing confirmed the detected intronic variant to result in two aberrant mRNA isoforms. In patient-derived cells immunoblots showed absence of PREP protein. CONCLUSION: Our data suggest PREP deficiency as the underlying cause of a syndromic neurodevelopmental disorder.

Female↗