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At least 19 recordsLinked to original sources
PubMed2025

Transcript-guided targeted cell enrichment for scalable single-nucleus RNA sequencing.

Large-scale single-cell atlases have revealed many aging- and disease-associated cell types, yet these populations are often underrepresented in heterogeneous tissues, limiting detailed molecular analyses. To address this, we developed EnrichSci-a scalable, microfluidics-free platform that combines hybridization chain reaction RNA fluorescence in situ hybridization (FISH) with combinatorial indexing to profile single-nucleus transcriptomes of target cell types with full gene-body coverage. Applied to oligodendrocytes in the aging mouse brain, EnrichSci uncovered aging-associated molecular dynamics across distinct oligodendrocyte subtypes, revealing both shared and subtype-specific gene expression changes. Additionally, we identified aging-associated exon-level signatures missed by conventional gene-level analyses, highlighting post-transcriptional regulation as a critical dimension of cell-state dynamics in aging. By coupling transcript-guided enrichment with a scalable sequencing workflow, EnrichSci provides a versatile approach to decode dynamic regulatory landscapes in diverse cell types from complex tissues.

Animals↗
PubMed2025

PUS7-dependent Ψ reshapes specific synaptic gene exons to facilitate fear extinction memory formation.

RNA modifications serve as dynamic regulators of neural plasticity through their ability to fine-tune transcript stability and splicing. Pseudouridine (Ψ), an evolutionarily conserved RNA modification catalyzed by pseudouridine synthases, plays established roles in neurodevelopment, yet its functional significance in activity-dependent behavioral adaptation remains poorly defined. Here, we investigate Ψ-mediated epitranscriptomic regulation within the infralimbic prefrontal cortex (ILPFC), a brain region requiring precise synaptic remodeling for the clinically relevant form of fear extinction memory. Combining transcriptome-wide pseudouridylation profiling with behavioral analysis in mice, we identified selective Ψ enrichment at exons of synaptic regulatory genes within ILPFC during fear extinction learning. Fear extinction in the ILPFC drives concomitant exonic Ψ deposition and upregulation of synaptogenic transcripts, processes that involve pseudouridine synthase PUS7. Crucially, PUS7 knockdown in the ILPFC selectively impaired fear extinction memory formation without altering baseline fear expression, establishing a causal link between Ψ-dependent RNA processing and activity-dependent synaptic structural remodeling in this microcircuit. Our findings demonstrate that PUS7-mediated Ψ modification spatiotemporally regulates activity-dependent RNA dynamics in the ILPFC, providing the evidence that epitranscriptomic mechanisms precisely coordinate synaptic gene expression within behaviorally defined brain sub-region. This work bridges molecular RNA biology with systems neuroscience, revealing a novel mechanism for activity-dependent regulation of fear extinction in ILPFC.

Animals↗
PubMed2026

From neuropeptides to toxins: illuminating the origins of venom complexity in cone snails.

New genes and gene functions are key drivers of evolutionary innovation. Venomous animals, such as cone snails, provide striking examples of gene innovation, yet the mechanisms by which toxins arise remain poorly understood. Using the Conus textile genome, we uncover how neuropeptide genes were recruited into the venom and neofunctionalized as doppelgänger toxins. We identify over 20 independent recruitment events that evolved dynamically across the Conus lineage. Rather than arising from ohnologs of a whole-genome duplication event ∼200 mya, these toxins evolved through diverse mechanisms, including exon shuffling, alternative splicing, and ectopic recombination, often facilitated by lineage-specific transposable elements. Our findings reveal a dynamic interplay between genome architecture and molecular innovation, offering broad insight into the evolution of complex gene repertoires in venoms and beyond.

Animals↗
PubMed2025

A CRISPR/Cas9 mutant resource for OsSm RNA-binding genes in rice.

Pre-mRNA, produced by eukaryotic DNA transcription, undergoes splicing by the spliceosome, which removes introns and joins exons to form mRNA. The spliceosome is a large and highly dynamic molecular machine. Its core components include five small nuclear ribonucleoproteins (snRNPs) and the various spliceosome-related proteins. The conserved Smith (Sm) complex and the Sm-like proteins (LSm) serve as primary components of the snRNPs. Sm proteins are involved in processes such as pre-mRNA splicing and mRNA degradation, which can regulate gene expression, thereby influencing plant growth, development, and stress responses. While 25 Sm proteins have been identified in rice, their specific roles in regulating rice growth and development remain unclear. In this study, we employed the CRISPR/Cas9 system to edit 15 OsSm genes, and 13 mutants were obtained, with mutation rates ranging from 20.83 to 83.87%. In comparison to the wild type (WT), the mutants exhibited dwarfism, reduced tiller numbers, lower seed-setting rates or sterility, and increased susceptibility to diseases. One Sm mutant, ossmf-2, exhibited dwarfism, delayed flowering, and small grains. Through transcriptome analysis, three target genes, OsMRG702, OsRGG2, and OsLA1, were identified. Mutations of the OsSmF protein may lead to the abnormal splicing of these genes and finally lead to the inhibition of growth and development. Our study first edited the OsSm genes and generated a mutant library in rice. Most of the mutants exhibited abnormal growth and development, underscoring the essential roles of OsSm proteins in rice physiology. Furthermore, this work addresses a critical gap in the functional characterization of Sm proteins in rice. The resulting mutant collection offers valuable germplasm resources and lays a theoretical foundation for elucidating the molecular regulatory networks involving spliceosomal components and their target genes in the control of crop growth, development, and reproduction.

Oryza↗
PubMed2026

MET Exon 14 Skipping Mutation in NSCLC: From Genomic Discovery to Biomarker-Guided Therapeutic Innovation.

INTRODUCTION: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, and the MET exon 14 skipping mutation is a key oncogenic driver, which promotes tumor progression and provides a new direction for precision therapy. METHODS: A systematic search of English-language literature and clinical trial data related to the MET exon 14 skipping mutation from 2020-2025 was performed to summarize the role of the mutation and therapeutic advances. RESULTS: DNA-based next-generation sequencing (NGS), RNA-based NGS, and RT-qPCR were employed as the main detection methods. Preclinical models confirmed that mutations promote tumor progression by activating the RAS/MAPK pathway. Clinical trials have reported objective remission rates (ORR) of 46-68% for first-line treatment with MET inhibitors in NSCLC patients harboring MET exon 14 skipping mutations. DISCUSSION: MET exon 14 skipping mutation as a therapeutic target for NSCLC has made significant progress, and MET inhibitors are more advantageous than chemotherapy and immunotherapy, and have been recommended by national and international guidelines as a first-line treatment option. Additionally, NGS technology has the potential to dynamically monitor tumor evolution and drugresistant mutations, thereby helping to realize precision medicine. CONCLUSION: The MET exon 14 skipping mutation is an important target for the precision treatment of NSCLC, and MET-TKIs have remarkable efficacy but a prominent problem with drug resistance. The construction of a precision medicine system encompassing diagnosis, treatment, and drug resistance management through multi-omics research, technological innovation, and international collaboration is a key direction for improving prognosis.

Humans↗
PubMed2026

THE1 repeats: Ancient endogenous retroviruses rampaging behind sarcoid myopathy.

Transposon-like human element (THE1) repeats are classified as part of the ERVL (endogenous retrovirus-like) -MaLR family and were previously thought to be remnants derived from retroviral infections in the germ cells of ancient primates. At present, at least 60,561 THE1 repeats have been mapped in the human genome, and they are divided into four subfamilies: THE1A, THE1B, THE1C, and THE1D. Although these repeats are largely silenced in somatic cells through multiple mechanisms, some of them are known to influence gene functions and genomic structures, particularly under disease conditions. Recently, we happened to identify the CIR1 driven from THE1B in the individuals with sarcoid myopathy (SM), which is characterized by the non-caseating granulomatous inflammation recognized in skeletal muscles biopsy. Retrotrans-genomics based on the COFFEE method showed that various THE1B fusion transcripts (THE1B/FTs) and retrotransposon-associated genomic dynamics in muscle of SM, including (1) splicing of THE1B to neighborhood exons, (2) expression of THE1B associated long noncoding RNAs in the intergenic regions, (3) ectopic expression of tissue specific transcripts driven by THE1B in SM, and (4) identification of a read through transcript, SIRPB1-SIRPD. Seven of eight THE1B/FTs downregulated by tofacitinib in cutaneous sarcoidosis were confined to the granuloma associated macrophage in sarcoidosis. The remaining transcript, SMFT4 exhibited stronger expression in mesenchymal stem cells. In addition, ectopic co-expression of canonical and LINE1 and THE1A-exonizing IL23R transcripts were identified in SM. This directory of THE1B/FTs in SM may serve as a fundamental molecular basis for understanding the pathogenesis of sarcoidosis.

Journal Article↗
PubMed2026

Long-read proteogenomic atlas of human neuronal differentiation reveals isoform diversity informing neurodevelopmental risk mechanisms.

RNA splicing shapes neuronal identity and disease risk, yet current maps lack the developmental resolution and depth to resolve this complexity. Here, we integrate deep long-read RNA sequencing and proteomics in induced pluripotent stem cell-derived cortical neurons to generate a high-resolution proteogenomic atlas of human neuron development. We identify 182,371 mRNA isoforms (over half previously unknown) and provide direct peptide evidence for the translation of hundreds of novel protein-coding sequences. Population genetics demonstrates that variants affecting novel exons and splice sites are under negative selection, underscoring the potential significance of these isoforms. During neuronal maturation, we observe that autism risk genes undergo dynamic isoform switching, including microexon inclusion and intron retention, that remodel key protein domains and regulatory regions. Furthermore, we uncover widespread, long-range coordination between alternative transcript processing events, including transcription start sites, exon splicing, and polyadenylation. Finally, our atlas enables variant reinterpretation in autism, highlighting the value of an isoform-centric view for interpreting pathogenic variation in neurodevelopment.

Humans↗
PubMed2026

Tandem duplication-driven expansion and UV-B stress adaptation of the LHC gene family in Artemisia annua L.

BACKGROUND: Artemisia annua L., is the primary natural source of the antimalarial drug artemisinin. In nature, fluctuating light is a major environmental stress that affects plant growth and artemisinin biosynthesis. Although the light-harvesting chlorophyll a/b-binding (LHC) superfamily plays a key role in mediating plant responses to fluctuating light, systematic research of this gene family in A. annua has not yet been conducted, limiting our understanding of light adaptation in this medicinally important species. RESULTS: This study investigated the evolutionary dynamics and functional adaptation of the light-harvesting chlorophyll a/b-binding (LHC) superfamily in A. annua, with a focus on the early light‑induced protein (ELIP) subfamily. Comparative genomics of 24 plant species showed that the LHC superfamily recently expanded in the examined Asteraceae lineages through duplication events. In A. annua, 229 LHC genes identified from four haplotype genomes comprised 205 allelic and 24 haplotype-specific loci, with the ELIP subfamily expanding significantly via tandem duplication. Notably, compared to non-Asteraceae plants, ELIPs exhibited a uniform single-exon architecture, indicating it is a genomic feature unique to Asteraceae plants. Population genomics of 41 individuals showed dynamic copy number variations ranging from 1 to 4 copies per locus. Interestingly, a structurally disrupted ELIP allele remained transcriptionally active and produced long aberrant transcripts, showing that this subfamily is still actively evolving. Under UV-B stress, AaELIP loci showed synchronized induction trend but differed in expression levels, suggesting a division into major and auxiliary roles within the expanded tandem cluster. Overall, while the response of ELIPs to light stress is evolutionarily conserved, this dramatic expansion and structural streamlining of AaELIPs may represent a key evolutionary adaptation that enhances the plant's ability to cope with intense light and radiation stress. CONCLUSIONS: Collectively, this study demonstrates a significant expansion of the LHC superfamily in A. annua, especially within the ELIP subfamily, as well as its robust response to UV-B treatment, underscoring the essential role of ELIPs in mediating light stress responses. These findings provide a valuable foundation for future research to uncover the molecular mechanisms underlying A. annua's adaptation to complex light environments.

Artemisia annua↗
PubMed2026

k-mer-based Upstream Preprocessing of long reads for Isoform Discovery.

Eukaryotic genes can encode multiple protein isoforms based on alternative splicing of their transcribed regions. Most modern novel isoform discovery methods function by identifying and assembling exon splice junctions from an RNA-seq sample. However, splice junctions can only be accurately annotated with time-intensive dynamic programming alignment. This manuscript introduces KuPID, a method for preprocessing long RNA-seq reads with the goal of better identifying novel isoform transcripts. KuPID utilizes k-mer sketching as a prefilter to quickly pseudo-align reads to known reference isoforms. Full alignment need only then be applied to reads that are most relevant to isoform discovery. Not only does KuPID speed up the discovery pipeline, it also increases downstream accuracy by filtering out extraneous reads. KuPID preprocessing simultaneously increases the f1 accuracy of isoform discovery pipelines by up to 11.6 points while decreasing the runtime by a factor of 2-3×;. An optional mode permits a KuPID sample to be paired with both isoform discovery and transcript quantification.

Journal Article↗
PubMed2004

EnsMart: a generic system for fast and flexible access to biological data.

The EnsMart system (www.ensembl.org/EnsMart) provides a generic data warehousing solution for fast and flexible querying of large biological data sets and integration with third-party data and tools. The system consists of a query-optimized database and interactive, user-friendly interfaces. EnsMart has been applied to Ensembl, where it extends its genomic browser capabilities, facilitating rapid retrieval of customized data sets. A wide variety of complex queries, on various types of annotations, for numerous species are supported. These can be applied to many research problems, ranging from SNP selection for candidate gene screening, through cross-species evolutionary comparisons, to microarray annotation. Users can group and refine biological data according to many criteria, including cross-species analyses, disease links, sequence variations, and expression patterns. Both tabulated list data and biological sequence output can be generated dynamically, in HTML, text, Microsoft Excel, and compressed formats. A wide range of sequence types, such as cDNA, peptides, coding regions, UTRs, and exons, with additional upstream and downstream regions, can be retrieved. The EnsMart database can be accessed via a public Web site, or through a Java application suite. Both implementations and the database are freely available for local installation, and can be extended or adapted to 'non-Ensembl' data sets.

Animals↗
PubMed2026

Promoter identity shapes splicing outcomes and fidelity.

Gene expression is a complex process subject to regulation at multiple functionally interconnected levels. One prominent example is the crosstalk between transcription and splicing regulation. Past work has shown that transcription can influence splicing in multiple ways, but a systematic investigation of this complex interplay is lacking. Here we employ massively parallel reporter assays of large combinatorial promoter-splice site libraries to dissect how promoter identity and transcription dynamics affect alternative splicing in human cells. We find that promoter identity, rather than expression level, exerts strong and highly context-specific effects on cassette exon inclusion, exceeding the effect of pharmacological inhibitors of transcription initiation or elongation. Groups of exons display coordinated promoter-dependent splicing behavior, and we identified predictive sequence and structural features underlying this sensitivity. Promoter and gene architecture also shape isoform diversity by modulating cryptic splice site usage. These findings present promoters as central regulators of splicing outcomes and fidelity.

Humans↗
PubMed2022

TTC5 syndrome: Clinical and molecular spectrum of a severe and recognizable condition.

Biallelic mutations in the TTC5 gene have been associated with autosomal recessive intellectual disability (ARID) and subsequently with an ID syndrome including severe speech impairment, cerebral atrophy, and hypotonia as clinical cornerstones. A TTC5 role in IDs has been proposed based on the physical interaction of TTC5 with p300, and possibly reducing p300 co-activator complex activity, similarly to what was observed in Menke-Hennekam 1 and 2 patients (MKHK1 and 2) carrying, respectively, mutations in exon 30 and 31 of CREBBP and EP300, which code for the TTC5-binding region. Recently, TTC5-related brain malformation has been linked to tubulinopathies due to the function of TTC5 in tubulins' dynamics. We reported seven new patients with novel or recurrent TTC5 variants. The deep characterization of the molecular and phenotypic spectrum confirmed TTC5-related disorder as a recognizable, very severe neurodevelopmental syndrome. In addition, other relevant clinical aspects, including a severe pre- and postnatal growth retardation, cryptorchidism, and epilepsy, have emerged from the reversal phenotype approach and the review of already published TTC5 cases. Microcephaly and facial dysmorphism resulted in being less variable than that documented before. The TTC5 clinical features have been compared with MKHK1 published cases in the hypothesis that clinical overlap in some characteristics of the two conditions was related to the common p300 molecular pathway.

Exons↗
PubMed2025

U2AF1 mutations rescue deleterious exon skipping induced by KRAS mutations.

The mechanisms by which somatic mutations of splicing factors, such as U2AF1S34F in lung adenocarcinoma, contribute to cancer pathogenesis are not well understood. Here, we used prime editing to modify the endogenous U2AF1 gene in lung adenocarcinoma cells and assessed the resulting impact on alternative splicing. These analyses identified KRAS as a key target modulated by U2AF1S34F. One specific KRAS mutation, G12S, generates a cryptic U2AF1 binding site that leads to skipping of KRAS exon 2 and generation of a non-functional KRAS transcript. Expression of the U2AF1S34F mutant reverts this exon skipping and restores KRAS function. Analysis of cancer genomes reveals that U2AF1S34F mutations are enriched in KRASG12S-mutant lung adenocarcinomas. A comprehensive analysis of splicing factor/oncogene mutation co-occurrence in cancer genomes also revealed significant co-enrichment of KRASQ61R and U2AF1I24T mutations. Experimentally, KRASQ61R mutation leads to KRAS exon 3 skipping, which in turn can be rescued by the expression of U2AF1I24T. Our findings provide evidence that splicing factor mutations can rescue splicing defects caused by oncogenic mutations. More broadly, they demonstrate a dynamic process of cascading selection where mutational events are positively selected in cancer genomes as a consequence of earlier mutations.

Journal Article↗
PubMed2025

Expanding and improving analyses of nucleotide recoding RNA-seq experiments with the EZbakR suite.

Nucleotide recoding RNA sequencing methods (NR-seq; TimeLapse-seq, SLAM-seq, TUC-seq, etc.) are powerful approaches for assaying transcript population dynamics. In addition, these methods have been extended to probe a host of regulated steps in the RNA life cycle. Current bioinformatic tools significantly constrain analyses of NR-seq data. To address this limitation, we developed EZbakR (https://github.com/isaacvock/EZbakR), an R package to facilitate a more comprehensive set of NR-seq analyses, and fastq2EZbakR (https://github.com/isaacvock/fastq2EZbakR), a Snakemake pipeline for flexible preprocessing of NR-seq datasets, collectively referred to as the EZbakR suite. Together, these tools generalize many aspects of the NR-seq analysis workflow. The fastq2EZbakR pipeline can assign reads to a diverse set of genomic features (e.g., genes, exons, splice junctions), and EZbakR can perform analyses on any combination of these features. EZbakR extends standard NR-seq mutational modeling to support multi-label analyses (e.g., s4U and s6G dual labeling), and implements an improved hierarchical model to better account for transcript-to-transcript variance in metabolic label incorporation. EZbakR also generalizes dynamical systems modeling of NR-seq data to support analyses of premature mRNA processing and flow between subcellular compartments. Finally, EZbakR implements flexible and well-powered comparative analyses of all estimated parameters via design matrix-specified generalized linear modeling. The EZbakR suite will thus allow researchers to make full, effective use of NR-seq data.

Software↗
PubMed2025

Genomic context-dependent roles of 5-hydroxymethylcytosine in regulating gene expression during rice drought response.

DNA methylation (5-methylcytosine, 5mC) is a key epigenetic regulator of genome stability and stress adaptation in plants. However, the functional role of its oxidative derivative, 5-hydroxymethylcytosine (5hmC), remains poorly understood in plant systems, largely due to its low abundance and unresolved enzymatic origins. Here, we integrated ACE-seq (APOBEC-coupled epigenetic sequencing) with an optimized Tn5mC-seq (transposase-based library preparation in the context of whole-genome bisulfite sequencing, WGBS) approach to generate the first single-base resolution map of 5hmC in rice (Oryza sativa), unveiling its stress-responsive dynamics and regulatory interplay with 5mC during drought adaptation. Genome-wide profiling revealed a basal 5hmC level of ~0.03 (defined as the ratio of C/(C + T) at each site), with drought triggering a pronounced reduction in 5hmC abundance and locus number, followed by incomplete recovery post-rehydration. Unlike 5mC, which accumulates in heterochromatin, 5hmC preferentially localized to euchromatic regions, including promoters, exons, and intergenic elements, and exhibited enrichment at ABA-responsive transcription factors (e.g., OsATAF1, bZIP50). Strikingly, drought induced an antagonistic relationship between 5hmC and 5mC, with the latter increasing globally to reinforce transposon silencing. Multi-omics analyses demonstrated that 5hmC depletion in promoters correlated with transcriptional downregulation, while its accumulation in gene bodies (notably 5'-UTRs) suppressed stress-responsive genes. These findings highlight 5hmC's bifunctional regulatory capacity, contingent on genomic context, and its role in balancing transcriptional plasticity with genome stability during stress. Our work establishes 5hmC as a dynamic epigenetic mark in plant environmental adaptation and provides a foundation for leveraging DNA hydroxymethylation in crop resilience engineering.

Oryza↗
PubMed2026

Genome-Wide Impact of Human DBR1 Depletion on RNA Processing Networks Reveal a Connection Between Pre-mRNA Splicing, mRNA Surveillance and Stress Granule Dynamics.

The RNA lariat debranching enzyme DBR1 is essential for intron turnover and RNA metabolism, yet its broader impact on transcriptome regulation remains incompletely defined. To elucidate the consequences of DBR1 depletion, we performed transcriptome-wide RNA sequencing of DBR1-knockdown and wild-type HEK293 cells. Differential expression analysis revealed widespread perturbations in pathways linked to RNA splicing, mRNA surveillance, translational control, and stress-granule biology. Many of the most significantly altered transcripts encode splicing factors and RNA quality-control components, underscoring DBR1's influence on post-transcriptional regulation. Alternative splicing analysis showed changes across multiple event types, with exon skipping accounting for >50% of events, followed by mutually exclusive exons, alternative 5' and 3' splice sites, and retained introns, indicating that DBR1 depletion induces pervasive splicing defects. Direct spliceosome inhibition using isoginkgetin (blocks tri-snRNP recruitment) and pladienolide B (targets SF3B1) reproduced the DBR1-KD mis-splicing patterns of cell signaling genes and factors involved in RNA metabolism, supporting a functional link between DBR1 activity and alternative splicing. Notably, DBR1 knockdown revealed a subset of transcripts that are both NMD-sensitive and enriched within stress granules. Consistent with this observation, G3BP1 immunopurification and confocal microscopy further support a role for DBR1 and UPF1 in stress-granule dynamics, suggesting that these factors may participate at distinct stages to influence mRNA fate under stress conditions. Together, these findings indicate that DBR1 functions beyond lariat RNA turnover as a common regulator of RNA processing, transcriptome stability, and stress granule homeostasis, revealing intricate crosstalk between RNA splicing and RNA quality control pathways in human cells.

Humans↗
PubMed2026

Transposable Element Dynamics Drive the Genomic Evolution and Phenotypic Diversification of Allotetraploid Common Carp.

An important question in evolutionary biology is how polyploidization generates raw material for phenotypic diversification. Transposable elements (TEs) represent an underestimated source of genetic variation in eukaryotic genomes. By integrating 516 whole-genome resequencing datasets and 236 transcriptomes from common carp (Cyprinus carpio), a representative allotetraploid fish, we constructed the first population-scale landscape of TE insertions in teleosts. TE insertions are widespread in the carp genome and preferentially associated with stress-responsive genes, with DNA transposons as major contributors. Relaxed purifying selection and TE burst events coexist, generating abundant variation for subsequent subspecies differentiation. Compared with a closely related diploid species, carp exhibits more exonic TE insertions and shorter TE-gene distances, and multiple TE superfamilies expanded during tetraploidization. Genome-wide association analyses uncovered intragenic TE variants underlying domesticated traits missed by SNPs, including DNA transposon deletions associated with scale reduction and altered body shape. Notably, lighter-colored individuals harbor homozygous deletions of LTR and DNA transposons within mdfic2, whose knockout in zebrafish reduces pigmentation. Most trait-associated variants reflect lineage-specific loss of ancient TE insertions rather than recent transposition. Overall, these findings highlight the distinct role of TEs in polyploid genome evolution and phenotypic diversification, providing new insights into TE dynamics in vertebrates.

allotetraploidization↗
PubMed2026

Hemizygous loss-of-function variants of EIF1AX are associated with a syndromic neurodevelopmental disorder.

Pathogenic variants of genes encoding initiation factors can cause neurological diseases, including neurodevelopmental disorders and brain abnormalities. The eukaryotic translation initiation factor 1 A, X-linked (EIF1AX) is a gene located at Xp22.12 that plays an important role in the regulation of translation initiation. Here, we identified de novo hemizygous EIF1AX variants in male individuals with neurodevelopmental disorders and explored their possible involvement in these neurological disorders. We performed trio-based exome or whole genome sequencing in four families. The pathogenicity of EIF1AX variants was evaluated using a molecular dynamic simulation and transgenic Drosophila models. We identified four de novo hemizygous EIF1AX variants in four male individuals with variable neurodevelopmental delay, dysmorphic features, behavioral problems, ophthalmological abnormalities, and structural abnormalities in the brain. One variant was predicted to cause a splicing alteration, and minigene analysis confirmed exon skipping leading to the generation of a premature termination codon. In transgenic Drosophila harboring wild-type (WT) EIF1AX or the three other EIF1AX missense variants, overexpression of WT and the p.(Asn17Asp) variant caused structural abnormalities in the compound eye, whereas the p.(Lys64Glu) and p.(Asp90Gly) variants significantly reduced these eye abnormalities. In addition, WT overexpression resulted in significant axonal toxicity in the Drosophila optic nerve, causing a significant reduction in the number of axons, whereas all mutants showed only a mild reduction in axonal number. Our findings indicated that all variants resulted in different degrees of EIF1AX loss-of-function. Overall, EIF1AX is a novel gene for which loss-of-function variants appear to produce syndromic neurodevelopmental disorders in males.

Humans↗