Search PubMedSearch

SEARCH · Search PubMed

Results for “single nucleotide variants”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

556 records · Page 5Linked to original sources

Evaluating the pathogenic significance of unique chromosomal variants in craniosynostosis using patient-derived induced pluripotent stem cells and mouse modelling.

PURPOSE: Unravelling causal links between unique structural/copy-number variants (SV/CNV) and associated phenotypes is essential for correct genetic counselling. We investigated two families in which patients with craniosynostosis had SV/CNV potentially dysregulating a fibroblast growth factor (FGF)-encoding gene; a 730 kb dup(4)(q21.21) including FGF5; and a complex 568 kb interspersed 13q12.11 duplication, located 841 kb from FGF9. METHODS: We combined bioinformatic predictions of altered topologically-associating domain (TAD) structure, with experimental analysis (RNA- and ATAC- [assay for transposase-accessible chromatin] sequencing) of patient induced pluripotent stem cell lines (iPSCs) differentiated to neural crest (NCC) and osteoprogenitor (OPC) identities. For the dup(4)(q21.21) we generated a mouse bearing an equivalent rearrangement using CRISPR-Cas9 targeting. RESULTS: TAD analysis suggested potential dysregulation of the FGF5/FGF9 gene by bringing it into a novel genomic milieu. The RNA- and ATAC-seq assays demonstrated FGF5/FGF9 upregulation (2.7-18x) and local opening of chromatin, in 3/4 cell lines. For the dup(4)(q21.21), a causal role was supported by the mouse model, whereas interpretation of the 13q12.11 SV is confounded by a co-existing FOXP2 pathogenic variant. CONCLUSION: Patient iPSC-differentiated NCC and OPC lines, combined with TAD-based modelling to generate testable functional hypotheses, provide valuable functional evidence when evaluating causation of unique SV/CNV in craniosynostosis.

copy-number variant

Genomic insights into end-use grain quality and nutritional traits of an ancient Indian dwarf wheat ( Triticum sphaerococcum Percival) population using a multi-locus genome-wide association study.

BACKGROUND: Triticum sphaerococcum, an ancient hexaploid wheat species, is renowned for its stress resilience and superior nutritional quality. A panel of 116 T. sphaerococcum accessions (the largest known collection at a single site globally), with six bread wheat released varieties, was evaluated for its potential for genetic quality improvement. Field experiments were conducted under standard, heat and moisture-deficit conditions across two cropping seasons for ten grain end-use quality and nutritional traits. RESULTS: Genotypes showed highly significant differences (P ≤ 0.001) for measured traits, with high broad-sense heritability resulting from substantial genotypic variance contributions. Triticum sphaerococcum consistently outperformed T. aestivum across environments, with moisture-deficit stress proving more detrimental to quality parameters than heat stress, while micronutrient content increased under stressed conditions. Trait correlations revealed that the gluten index (GI) correlated negatively with the grain hardness index (GHI), wet gluten (WG), and water-binding capacity (WB), while positively correlating with dry gluten (DG) and protein content (PRO), whereas grain iron (GFE), zinc (GZN), and protein showed consistent positive interrelationships. Two superior accessions, PAUTS10 (WG 35.13%, DG 13.71%, PRO 16.42%, GZN 50.89 ppm) and Sonamoti (WG 33.33%, DG 12.92%, PRO 16.27%, GZN 56.03 ppm), were identified, surpassing the best check variety HD3226 for quality and nutritional parameters. Multi-locus genome-wide association studies identified 30 stable quantitative trait nucleotides across environments, with candidate gene analysis revealing genes involved in transcription regulation, biosynthetic processes, metal ion homeostasis, and transport. CONCLUSIONS: Triticum sphaerococcum demonstrated superior grain quality and micronutrient potential compared with modern wheat, highlighting its value as a genetic resource for biofortification. The identification of elite accessions and stable quantitative trait nucleotides (QTNs) provides useful targets for breeding programs aimed at improving protein and micronutrient content. Integrating ancient germplasm with modern genomic tools can accelerate the development of nutritionally enhanced wheat varieties. © 2026 Society of Chemical Industry.

Triticum

Genetic Ancestry and Carrier Variant Frequency Enrichment in a Colombian Andean Population: Insights From the Eje Cafetero.

Colombia is one of the most genetically diverse populations in Latin America, and its demographic process has promoted the persistence and local enrichment of deleterious alleles, increasing the frequency of autosomal recessive disorders, particularly in semi-isolated Andean populations such as the Eje Cafetero. However, exome-based reference data from this region remain scarce, limiting ancestry-aware variant interpretation and carrier screening strategies. We aimed to characterize the ancestry proportions of this population using exome data, and to estimate the carrier frequency and distribution of pathogenic and likely pathogenic (P/LP) variants in clinically relevant recessive genes. We conducted a cross-sectional study with whole-exome sequencing (WES) in 316 unrelated individuals from the Colombian Eje Cafetero. P/LP variants were evaluated in 454 genes associated with autosomal recessive disorders. The global ancestry proportions were estimated using a validated panel of 250 exome-compatible ancestry-informative markers. Carrier frequencies were compared against Non-Finnish Europeans (NFE) and Admixed Americans (AMX) from gnomAD v4. The cohort showed predominant European ancestry (mean 51%), followed by Native American (36%) and African (13%) components. We identified 151 carriers of 89 distinct pathogenic variants across autosomal recessive genes. The most frequent variants were SERPINA1 c.863A>T (5.5%), CFTR c.1210-11T>G (3.5%), and PYGM c.1094C>T (1.5%). Also, recurrent variants were significantly enriched compared with both NFE and AMX populations, supporting regional founder effects. This study represents one of the most comprehensive exome-based genetic characterizations of the Colombian Eje Cafetero, revealing ancestry-specific enrichment of clinically relevant autosomal recessive variants driven by founder effects.

Female

[Analysis of clinical phenotypes and pathogenicity of a c.4476+5G>T variant of SCN1A gene in a Chinese pedigree affected with Genetic epilepsy with febrile seizures plus].

OBJECTIVE: To explore the pathogenicity and characteristics of a heterozygous splicing variant of SCN1A gene in a Chinese pedigree affected with Genetic epilepsy with febrile seizures plus (GEFS+). METHODS: A retrospective analysis was carried out on the clinical data and results of genetic testing of a GEFS+ pedigree consisting of 5 members who had visited the First Affiliated Hospital of Zhengzhou University on July 1, 2024. Pathogenicity of the splicing variant of the SCN1A gene was validated with a minigene splicing assay. This study was approved by the Medical Ethics Committee of the the First Affiliated Hospital of Zhengzhou University (Ethics No.: KS-2018-KY-36). RESULTS: The proband, a 24-year-old female, presented with FS in conjunct with focal seizures, and both of her younger brothers had Dravet syndrome. All of the three patients had carried a c.4476+5G>T variant of the SCN1A gene, which was unreported previously. Minigene experiment verified that the variant could cause loss of the first 7 bps of exon 24 and 138 bps from exon 23 of the SCN1A gene, resulting in alteration p.V1447_1495delfs*6 and affecting splicing. Based on the guidelines from American College of Medical Genetics and Genomics (ACMG), the variant was predicted as likely pathogenic (PVS1+PM2_Supporting). CONCLUSION: The c.4476+5G>T variant at an intronic site of the SCN1A gene probably underlay the pathogenesis of GEFS+ in this pedigree.

Adult

Pathogenic Variants in HEPACAM Alter Protein Localization and Interactome in Astrocytes of the Developing Mouse Cortex.

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare leukodystrophy characterized by early-onset macrocephaly, white matter edema, seizures, and motor and cognitive decline. Approximately 25% of MLC patients carry HEPACAM pathogenic variants, many of which are dominant missense variants causing remitting MLC Type 2b. HEPACAM encodes hepatic and glial cell adhesion molecule (hepaCAM), also known as GlialCAM, an astrocyte-enriched transmembrane protein with important roles in astrocyte territory establishment, gap junction coupling, branching organization, synaptic function, and development of the gliovascular unit. The molecular mechanisms through which pathogenic variants in HEPACAM alter hepaCAM protein function in vivo and facilitate MLC pathogenesis during brain development remain largely unknown. Here, we used new viral tools and proximity-based proteomics to examine how three different dominant pathogenic variants alter hepaCAM subcellular localization and protein interactome in astrocytes of the developing mouse cortex. We found dramatic changes in hepaCAM distribution throughout the astrocyte, which were common to all mutants tested. We also observed significant changes in protein interactome between wild type and mutant hepaCAM, including decreased association with previously described hepaCAM-interacting proteins Connexin 43 and CLC-2. Moreover, we identified the epilepsy-associate potassium channel KCNQ2 as a novel hepaCAM interaction partner and found reduced association between KCNQ2 and pathogenic variants. Collectively, our data provide new insights into hepaCAM protein function in astrocytes during brain development, reveal altered protein dynamics of pathogenic variants, and provide a new resource to explore the molecular underpinnings of MLC pathogenesis.

Animals

[Pathogenicity analysis and prenatal genetic counseling for five Chinese pedigrees harboring a hemizygous c.-32C>G variant of FGF13 gene].

OBJECTIVE: To explore the pathogenicity and prenatal counseling strategies for five Chinese pedigrees harboring a hemizygous c.-32C>G (NM_001139500.2) variant of fibroblast growth factor 13 (FGF13) gene. METHODS: Five Chinese pedigrees found to carry a hemizygous c.-32C>G variant of the FGF13 gene at the Prenatal Diagnosis Center of Henan Provincial People's Hospital between January 2024 and January 2025 were selected as study subjects. The pedigrees had undergone prenatal diagnosis for a family history of genetic disorders, abnormal fetal ultrasound findings, or advanced maternal age. A retrospective analysis was carried out, wherein clinical data for all members of the pedigrees were obtained through the medical records system and outpatient visit system. Peripheral blood samples were collected from all pedigree members, and amniotic fluid samples were obtained from the probands. Following extraction of genomic DNA, prenatal diagnosis was performed using chromosomal microarray analysis (CMA) and trio whole-exome sequencing (trio-WES). Sanger sequencing was used to determine the carrier status for the candidate variant, and Mini-Mental State Examination (MMSE) was used to assess the cognitive function of hemizygous individuals carrying the FGF13 gene c.-32C>G variant. Pathogenicity of candidate variant was assessed based on guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2021-171). RESULTS: CMA and trio-WES revealed no pathogenic variants in all probands, whilst trio-WES and Sanger sequencing had identified 11 male individuals carrying a hemizygous c.-32C>G variant of the FGF13 gene from the five pedigrees, which included six adult males, a young boy, and four fetuses. One fetus had undergone termination of pregnancy due to hydrocephalus, one was born pre-term at 34+1 weeks of gestation owing to maternal hypertension, and other two were delivered at full term. Follow-up of the survived males revealed no phenotypic manifestations related to language or intellectual impairment. Among these, three adult males underwent the MMSE assessment, all of whom showed normal cognitive function. Search of the gnomAD database suggested the carrier frequency of FGF13 c.-32C>G variant in the East Asian population to be 0.125%, with 11 hemizygous males documented. Three male patients harboring the variant showed severe intellectual disability. Both in vitro and in vivo studies suggested that it could reduce the translation levels of FGF13 protein. Based on the ACMG guidelines, it was classified as variant of uncertain significance (BS4+PS3_Supporting). CONCLUSION: There is insufficient evidence to classify the FGF13 c.-32C>G as a pathogenic variant in clinical practice, and its presence should not be considered an indication for pregnancy termination due to major birth defects.

Adult

[Analysis of a Chinese pedigree affected with Townes-Brocks syndrome due to a novel variant of SALL1 gene and a literature review].

OBJECTIVE: To analyze a novel exonic variant of the SALL1 gene and its impact on the binding site of SALL protein. METHODS: Clinical data of three children diagnosed with Townes-Brocks syndrome and their family members who had presented at the First Affiliated Hospital of Shandong First Medical University in April 2022 were retrospectively collected. The pathogenic variant was identified through whole-genome sequencing (WGS) and validated by Sanger sequencing. Protein structural prediction was performed using AlphaFold and PyMOL software to construct three-dimensional models of the wild-type and mutant proteins. Additionally, previously reported cases were systematically reviewed. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2023-386). RESULTS: The proband was one of triplet sisters born at 34+4 gestational weeks. All three cases had presented with anal atresia and rectovaginal fistula, and case 3 also had toe malformation of left foot. WGS revealed a novel heterozygous c.757C>T (p.Gln253*) variant in the SALL1 gene, which was predicted to be pathogenic. Sanger sequencing confirmed co-segregation of the variant with the disease within the family. Protein structural modeling demonstrated that the variant has introduced a premature stop codon at position 253, resulting in a truncated protein. CONCLUSION: Above finding has enriched the mutation spectrum of the SALL1 gene in association with Townes-Brocks syndrome, which also represented a rare case of anal atresia in triplets, and provided a basis for molecular diagnosis, genetic counseling, and further research.

Humans

LINE-1 repeats are a defining feature of the Xce.

During early development, female mammals inactivate one X chromosome to balance their X-linked gene dosage with males. While allelic choice is random in inbred mouse populations, choice can be significantly skewed in interstrain hybrids. The genetic basis of skewing has long been attributed to the mysterious "X chromosome controlling element(s)" (Xce) with different strengths among species, subspecies, and strains. When two X-chromosomes with different Xce strengths are inherited by offspring, the X chromosome with the stronger Xce will have a higher probability of remaining active. Here, we provide evidence that L1Tf repeats-a subfamily of long interspersed nuclear elements 1-plays a role in determining Xce strength. L1Tf elements form a condensed core within the inactive X (Xi) territory. Mouse strains with varying Xce strengths differ in the L1Tf copy number on the X chromosome, with the strength of the Xce allele being inversely related to L1Tf copy number. L1Tf expression mediates the Xce effect. However, in contrast to a prior report, L1Tf RNA does not coat the Xi. Rather, L1Tf promotes condensation of the Xi core. Intriguingly, L1Tfs recruit and sequester YY1 from active genes, accelerating XCI in cis. Thus, L1Tf copy number, expression, and binding of YY1 are key defining features of the Xce. We propose a model in which the Xce influences the choice of Xist alleles by promoting YY1 binding to the nucleation site for the initiation of Xist spreading.

Animals

[Study of a patient with azoospermia due to variant of MOV10L1 gene].

OBJECTIVE: To explore the clinical and genotypic characteristics of a patient with Sertoli cell-only syndrome (SCOS) due to variants of MOV10L1 gene. METHODS: A 27-year-old patient with Non-obstructive azoospermia (NOA) underwent routine semen analysis. Serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone (P), estradiol (E2), prolactin (PRL), and testosterone (T) were determined by chemiluminescence assays. Peripheral blood samples were collected for G-banded karyotyping analysis. Multiplex PCR fluorescence detection was used to screen for AZF gene microdeletions. Whole exome sequencing (WES) and Sanger sequencing were performed simultaneously. Testicular biopsy tissues were subjected to Hematoxylin-Eosin (HE) staining to assess seminiferous tubule cell composition, and MOV10L1 protein expression was detected by immunohistochemical staining. Bioinformatics tools were employed to predict the pathogenicity of variants and their impact on protein structure and function. This study was approved by the Medical Ethics Committee of the Guangdong Institute of Reproductive Sciences [Ethics No.: 2023(01)]. RESULTS: The patient's two semen analyses had failed to detect any sperm. Hormone tests indicated elevated FSH (22.32 mIU/mL) and PRL (397.6 mIU/mL), while T (3.68 nmol/L) and E2 (38.32 pmol/L) were reduced. Chromosomal karyotyping revealed 46,XY, and no AZF gene deletion was detected. WES and Sanger sequencing detected compound heterozygous variants of the MOV10L1 gene, including a c.345C>A (p.C115X) nonsense variant and a c.3323C>T (p.T1108I) missense variant, with the former being unreported previously. HE staining showed only Sertoli cells in the seminiferous tubules, confirming the diagnosis of SCOS. Immunohistochemical staining revealed absent MOV10L1 protein expression in the testicular tissue. Based on the guidelines from American College of Medical Genetics and Genomics (ACMG), the c.345C>A (p.C115X) was classified as a pathogenic variant (PVS1+PM2_Supporting+PP4), while the c.3323C>T (p.T1108I) was deemed variant of uncertain significance (PM2_Supporting+PP3_Supporting+PP4). Bioinformatics analysis demonstrated that c.345C>A (p.C115X) may cause premature termination of protein translation, while c.3323C>T (p.T1108I) may disrupt the hydrophobicity of the RNA helicase domain, reducing the active pocket volume and decreasing its affinity for MILI protein. CONCLUSION: This study has diagnosed a case of SCOS due to compound heterozygous variants of the MOV10L1 gene, which also enriched its mutational spectrum.

Humans

Upscaling Genotyping by Amplicon Sequencing With GBAS-GUI.

Genotyping by amplicon sequencing (GBAS) is a relatively low-cost approach for generating genotypic data compared with established genomic methods, making it highly scalable and particularly suitable for large-scale genetic monitoring projects. However, most existing analytical pipelines are either marker-specific, insufficiently scalable, or lacking efficient data management systems for the long-term integration of genotypic information, limiting the full potential of GBAS. Here, we address this gap by introducing GBAS-GUI (https://github.com/sonnenbe-dot/GBAS-GUI), a pipeline capable of generating GBAS-based genotypic data for a wide variety of loci at scale. GBAS-GUI integrates a graphical user interface with multiple checkpoints to improve accessibility and robustness. It implements multiprocessing architecture and a relational database that links genotypic data with associated sample metadata to enhance scalability and data management. The pipeline further enables marker screening through automated calculation of polymorphism information content (PIC) and implements a strategy to recover homologous genotypic information from paralogous loci with non-overlapping amplicon length ranges. Using multiple empirical datasets, we demonstrate substantial improvements in processing speed, database management and handling artefacts related to co-amplification of unspecific regions and duplicates of the same genomic region. We further show that incorporating the full sequence information captured by an amplicon increases marker information content beyond what is achievable with length-based genotyping alone and expands the analytical versatility of GBAS. Overall, GBAS-GUI provides a robust, scalable and versatile framework that unlocks the potential of GBAS for large-scale population genetic and phylogeographic studies.

Genotyping Techniques

Germline variants and impact on lung cancer outcomes following chemotherapy: A systematic review.

BACKGROUND: Lung cancer is the primary cause of cancer deaths in the UK and globally, and the main subtypes are non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Many treatment options are available, with platinum-based chemotherapy being a key component for many patients. However, variation in survival outcomes exists among individuals of European ancestry, which makes it important to identify germline genetic variants that help guide decision-making and optimise patient treatment and outcomes. METHOD: A systematic literature search was conducted in PubMed and Web of Science for lung cancer studies investigating the impact of germline genetic variants on systemic anti-cancer therapy (SACT) outcomes in populations of European ancestry. The review was conducted according to the Preferred Reporting Items of Systematic Review and Meta-Analysis (PRISMA) and Synthesis without Meta-Analysis (SWiM) guidelines. RESULTS: A total of 20 studies were included in the review out of 4469 on NSCLC and SCLC, encompassing 3639 patients. The most thoroughly investigated area was NSCLC treated with platinum-based chemotherapy. Genetic variants associated with overall survival and/or progression-free survival included XPD Lys751Gln, XPD Asp312Asn, ERCC1 C118T, and XRCC1 Arg399Gln. For non-platinum-treated NSCLC and SCLC, there was insufficient evidence to conduct a meaningful investigation. CONCLUSION: The XPD Lys751Gln, XPD Asp312Asn, ERCC1 C118T, and XRCC1 Arg399Gln variants showed potential associations with survival outcomes among patients of European ancestry with NSCLC after platinum-based chemotherapy. To support clinical implementation, large real-world pharmacogenomics studies stratified by ancestry are needed to overcome statistical power and heterogeneity limitations.

Humans

The Homozygous p.(Arg215Ter) Variant in XRCC2 Is Associated With Atypical Fanconi Anemia Without Major Hematological Abnormalities in Childhood.

Fanconi Anemia (FA) is the most frequent inherited bone marrow failure syndrome. A role for the XRCC2 gene in FA was suspected in 2012 and confirmed in 2016, but only two affected individuals have been described thus far, and no long-term follow-up is available. Here we present two young related adults born to consanguineous parents, in whom we identified the homozygous p.(Arg215Ter) variant in XRCC2. Both patients presented with mild intellectual disability, microcephaly, distinctive facial features, short stature, thumb abnormalities, and abnormal skin pigmentation. Unlike in FA, DEB test resulted negative in peripheral blood during childhood and no cytopenia, clonal evolution, or other hematological complications were detected until the age of 19 and 20 years, respectively. Our report suggests that the homozygous p.(Arg215Ter) variant in XRRC2 causes a distinctive FA-like disorder, characterized by the typical physical characteristics seen in FA, but a lack of major hematological manifestations in childhood, and the presence of a more pronounced neurodevelopmental phenotype than that seen in FA.

Humans

Cross-species variant-to-function analyses implicate MEIS1 in conferring sleep abnormalities and impaired cerebellar development.

Genome-wide association studies (GWAS) have identified numerous loci for insomnia, yet functional validation of effector genes remains limited because most risk variants lie in noncoding regions, and the true causal gene is not known. Here, we use prior human cell-based variant-to-gene mapping to nominate six insomnia effector genes and test them in zebrafish, a tractable diurnal vertebrate model well suited for sleep phenotyping. Our CRISPR-based behavioral screening identifies the MEIS1 ortholog, meis1b, as a regulator of sleep maintenance, with crispants displaying impaired nighttime-specific sleep maintenance and increased sleep latency. Comparative chromatin analyses reveal conserved regulatory architecture spanning the human insomnia-associated locus and selectively implicate meis1b, whereas the duplicated ohnolog meis1a was dispensable. Developmental profiling further shows that meis1b is expressed in cerebellar granule progenitors, paralleling human MEIS1 expression, and that its disruption impairs cerebellar development. Together, these findings establish zebrafish as an efficient vertebrate platform for functional interrogation of GWAS candidates and support an evolutionarily conserved cerebellar role for MEIS1 in sleep maintenance.

Animals

Somatic mutations: recent advances in brain aging and neurodegeneration.

Somatic mutations are genetic variants that occur after the single-cell phase of development and have been implicated in disease pathogenesis. While most DNA lesions are detected and repaired, examination of healthy tissue has revealed that some lesions escape repair, leading to somatic mutations that accumulate at a consistent rate, including in human brain tissue and postmitotic neurons. Emerging methodological and analytical advances have revealed the presence of persistent mutagenic mechanisms during healthy brain aging as well as mutational pattern shifts in the context of neurodegenerative diseases. Here, we highlight recent methodological advances, summarize our current understanding of somatic mutagenesis in neurotypical brain aging, and examine the role of somatic mutations in neurodegenerative diseases.

Humans

Mitochondrial DNA diversity in Ecuadorian populations: Recurrence of variant 16136 within haplogroup B2.

The identification of lineage-defining variants, frequently found in the coding region of mitochondrial DNA (mtDNA), is essential for refining haplogroup classification. Most mtDNA studies in South American populations have focused on the control region (CR), which has provided important insights into population structure and maternal lineage origins, although information needed for more robust phylogenetic resolution has been neglected. This study investigates the maternal genetic structure of Ecuadorian populations by combining CR and whole mitogenome analyses. Sequences from the mtDNA CR were obtained from 461 individuals (253 Mestizos and 208 Native Americans), while complete mitogenomes were sequenced for 127 individuals to improve phylogenetic resolution by identifying lineage-defining variants present in coding region. Most mtDNA haplogroups in the two population groups analyzed were of Native American origin (A2, B2, B4, C1, D1, D4), with significant differences in the distribution of specific lineages between them. Among Mestizos, African haplogroups (all within the L branches) and Eurasian haplogroups (H, K, R, U) were detected at low frequencies, whereas no African lineages were observed among Native Americans. The results obtained highlighted a heterogeneity within Ecuadorian populations that must be considered when developing mtDNA haplotype databases for forensic purposes. Whole mitogenome sequences enabled the identification of variants that refined haplogroup classifications, provided a more accurate reconstruction of the maternal genetic diversity, and improve the discrimination between Native American and Asian maternal lineages within haplogroup B4b.

Humans

Differential contributions of mt-Tr and Cs variants to developmental cochlear defects and mitochondrial dysfunction in A/J mice.

A/J mice exhibit early-onset hearing loss linked to Cdh23, mitochondrial tRNA-Arg (mt-Tr), and citrate synthase (Cs) variants. Although developmental cochlear defects have been identified in juvenile A/J mice, the hierarchical contributions of mt-Tr versus Cs remain unclear. Using reciprocal intercross-derived strains to decouple mitochondrial haplotypes from nuclear factors, we demonstrate that the mitochondrial background is the primary determinant of auditory dysfunction. Mice with A/J mtDNA (AXB strains) displayed significantly higher ABR thresholds, accelerated hair cell attrition, and severe stereocilia dysmorphology compared to those with B6 mtDNA (BXA strains), occurring largely independently of the Cs genotype. While the Cs mutation exacerbated hearing loss, its impact was secondary to that of the dominant mitochondrial background. Systemic behavioral assessments and mitochondrial assays confirmed that A/J mitochondria exert a more profound metabolic impact than the Cs mutation. Our findings establish that the mitochondrial genomic background, with the mt-Tr locus as a prominent candidate variant, serves as the principal driver of developmental cochlear defects and early-onset hearing loss in A/J mice, while the nuclear Cs mutation acts as a synergistic modifier. This study underscores the critical role of mitonuclear crosstalk in inner ear maturation and provides new insights into the etiology of hereditary hearing loss.

Animals

Performance comparison of rapid and native barcoding methods for Oxford Nanopore sequencing of Poliovirus Viral Protein 1 (VP1) amplicons.

Accurate and timely sequencing of poliovirus is critical for global eradication efforts, particularly for molecular epidemiology based on the typing region of the genome, viral protein 1 (VP1). While Oxford Nanopore Technologies (ONT) sequencing has expanded capabilities for poliovirus surveillance, the relative performance of different ONT library preparation methods, including ligation-based (Native Barcoding) and transposase-based (Rapid Barcoding) approaches, has not been systematically evaluated. In this study, we compared rapid barcoding and native barcoding workflows for sequencing VP1 amplicons from 17 type 2 poliovirus-positive samples, each processed in triplicate. Native barcoding generated significantly more sequencing output, producing approximately 2.3-fold greater total read yield than rapid barcoding, and demonstrated higher run-to-run reproducibility (R2 = 0.979-0.998 vs. 0.847-0.929, respectively; p&#x202f;<&#x202f;0.001). In addition, native barcoding generated 80% of the total yield achieved by rapid barcoding within approximately 7&#x202f;h, whereas rapid barcoding required approximately 40&#x202f;h to reach the same output. Despite these differences, both methods produced identical VP1 consensus sequences across all samples, with comparable read quality (median per-base Q-scores of approximately Q17-Q18). Rapid barcoding provided substantial practical advantages, reducing hands-on library preparation time (55 vs. 200&#x202f;min) and per-sample cost ($12.82 vs. $16.54), while simplifying workflow and reducing technical complexity. These findings indicate that sequencing yield may not be a determinant of downstream analytical outcomes for poliovirus VP1 ONT sequencing. Rapid barcoding therefore represents a cost-effective and efficient approach for routine poliovirus surveillance, whereas native barcoding remains advantageous in applications requiring rapid data generation or maximal sequencing depth.

Poliovirus

Comprehensive analysis of mRNA-microRNA-lncRNA expression profiles in post-traumatic elbow heterotopic ossification using RNA sequencing and experimental validation.

BACKGROUND: This study aimed to profile the molecular signatures of post-traumatic elbow heterotopic ossification (HO) to identify key regulators and potential therapeutic targets. METHODS: Total RNA from post-traumatic elbow HO tissues (n=4) and normal bone tissues (n=6) was subjected to high-throughput sequencing to identify differentially expressed mRNAs (DEGs), microRNAs (DEMs), and lncRNAs (DELs). Bioinformatics analyses included Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, protein-protein interaction network construction, and transcription factor (TF)-microRNA-mRNA network analysis. The expression trends of four most upregulated and four most downregulated DEGs were validated by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: We identified 2,138 DEGs, 40 DEMs, and 905 DELs. DEGs were significantly enriched in biological process "bone mineralization," cellular component "plasma membrane," molecular function "integrin binding," and pathways including PI3K-Akt, NF-&#x3ba;B, JAK-STAT, and TNF signaling pathways. Hub genes with high connectivity included MMP9, IL6, MMP3, CTSK, and BGLAP. Integrated network analysis highlighted the transcription factor JUN and key microRNAs (hsa-miR-124-3p, hsa-miR-548c-3p, and hsa-miR-135b). The qRT-PCR results confirmed the expression trends of selected DEGs. CONCLUSIONS: This study, for the first time, profiled the differentially expressed mRNAs, microRNAs, and lncRNAs in post-traumatic elbow HO using high-throughput RNA sequencing. These findings provide valuable insights into the molecular mechanisms of HO following elbow trauma. The identified hub genes (MMP9, IL6, MMP3, CTSK, and BGLAP), key TF (JUN), and key microRNAs (hsa-miR-124-3p, hsa-miR-548c-3p, and hsa-miR-135b) may serve as potential therapeutic targets for preventing and treating post-traumatic elbow HO.

Humans