Search Results (269)

Background: Two Shiba Inu littermates presented for investigation of marked and persistent elevation of creatine kinase activities. Method and Results: Histopathology of muscle biopsy samples revealed a dystrophic phenotype and immunostaining confirmed an absence of dystrophin protein in both cases. Whole genome sequencing of one affected dog revealed a complex deletion in the DMD gene encompassing exon 5. Screening of 27 related dogs confirmed an X-linked inheritance. The variant was identified in three related male dogs. One littermate died from cardiac arrest and the other littermate had no clinical myopathic signs at the time of the manuscript’s preparation. An additional related male dog reportedly died suddenly during grooming. Conclusion: This study adds a new breed to the canine dystrophinopathy spectrum having a ~17 kb deletion that encompasses exon 5 of DMD. This same exon 5 deletion has been identified in human dystrophin-deficient muscular dystrophy patients. Full article

After intensive artificial selection, the development of celestial eyes in goldfish involves the eyeballs protuberating and turning upwards. Thus, the celestial eye goldfish is an excellent model for both evolutionary and human ocular disease studies. Here, two mapping populations of goldfish with segregating eye phenotypes in the offspring were constructed. Through whole-genome sequencing and RNA-seq for eyeball samples, a premature stop codon in Exon 38 of the LRP2 gene was identified as the top candidate mutation for the celestial eye in goldfish. Fatty acid metabolism and epidermal cells, especially keratocyte-related functions, were inhibited in the eyeballs of celestial eye goldfish, while inflammatory reactions and extracellular matrix secretions were stimulated. These results suggest the dysfunction of the cornea in the celestial eye goldfish, and the same for the retina, which could be the results of the truncated LRP2 protein. In addition, the same gene, LRP2, is in charge of similar phenotypes (celestial eye and telescope eye) in goldfish, but these phenotypes have no shared mutations. In conclusion, the candidate mutation for the celestial eye in goldfish was identified by this study for the first time, and parallel evolutions of similar phenotypes at the molecular level under artificial selection were observed. These findings provide insights into the developmental and evolutionary processes of morphological changes in the eyes of goldfish. Full article

Background: Cardiovascular diseases remain a leading cause of death worldwide, yet the prevalence of pathogenic and likely pathogenic genetic variants associated with them is still underassessed in some populations. This study aimed to assess the frequency and geographic distribution of such variants within a representative sample of the Russian population. Additionally, it explored potential links between genotype and phenotype in a cohort of long-lived adults. Methods: We analyzed whole-genome sequencing data from 75,144 adults and 2,872 individuals aged 90 and older. Variants within 37 ACMG v3.1 genes were examined using InterVar, focusing on nonsynonymous variants and indels across exons and splicing sites. Variants were grouped based on ClinVar (as of 24 April 2023) annotations, with most subjected to manual review to confirm their significance. Results: Among the adult participants, 3,817 (5.1%) carried at least one of the variants under consideration. Of these, 141 (0.19%) carried pathogenic, 580 (0.77%) likely pathogenic, and 3,127 (4.16%) variants of uncertain significance. Variants not registered in ClinVar were found in 1,782 individuals (2.37%). Notably, one participant with cardiomyopathy carried a heterozygous TTN variant. In the long-lived cohort, 15 variants were classified as pathogenic or likely pathogenic, alongside 72 uncertain variants; overall, 19 individuals (0.66%) carried pathogenic or likely pathogenic variants. No significant difference was observed in variant frequency between the adult and long-lived groups. Conclusions: This study provided essential insights into the prevalence and geographic distribution of cardiovascular disease-related variants in Russia, laying the foundation for targeted genetic screening disease prevention strategies within this population. Full article

Allele-specific expression (ASE) reflects the unequal expression of the parental alleles and can imply functional variants in cis-regulatory elements. The conventional ASE detection methods often depend on the presence of heterozygous variants in transcripts or sequencing a large number of individuals, both of which are often limited. In this study, we present a family-based strategy for detecting ASE and potential cis-regulatory elements utilizing both RNA-seq and whole-genome sequencing (WGS) from a pedigree. Using a rabbit family consisting of two divergent parents and their eight offspring, we identified 913 ASE genes by analyzing inheritance patterns of gene expression levels. Expression was classified into three levels—high, medium, and low—and used to define seven distinct expression groups across the family (e.g., H_L: high in the mother, low in the father, and intermediate in the offspring). Many ASE genes lacked heterozygous exonic variants, and inference was achieved via RNA read count patterns. We also pinpointed conserved transcription factor binding sites (TFBS) with sequence variants showing similar inherited genotypic patterns (e.g., AAxBB), suggesting their regulatory roles as eQTLs. Differential gene expression (DEG) analysis between the parents highlighted some candidate genes related to meat production and quality traits. Our findings show that the family-based method using RNA-seq and WGS data is promising for exploring ASE and mapping possible eQTLs. Full article

The kuruma shrimp (Penaeus japonicus), a globally high-value aquaculture species, faces critical challenges in sustainable development due to genetic diversity degradation and declining disease resistance. This study employed whole-genome resequencing (WGRS) to systematically assess genetic diversity, population structure, and core germplasm characteristics across 20 geographically distinct populations from Zhejiang, Fujian (China), and introduced Japanese stocks. Using 343.40 Gb of high-quality sequencing data (average depth: 12.44×), we identified 9,146,248 single nucleotide polymorphisms (SNPs), with 6.32% located in exon regions, while intergenic (56.75%) and intronic regions (30.99%) showed the highest polymorphism density. Principal component analysis (PCA) and phylogenetic tree construction revealed two major clades: Fujian (FJ) and Japan-introduced (RB) populations clustered closely due to shared artificial breeding backgrounds, whereas Zhejiang (XS) and Fujian (LS) populations displayed genetic heterogeneity driven by adaptive divergence. Core germplasm screening via the CoreHunter algorithm selected four representative individuals (FJ4-M, LS1-M, XS1-M, XS6-M), with the modified Rogers’ distance (0.34) and allele coverage (0.93) confirming effective preservation of original genetic diversity. This study provides genomic insights and technical frameworks for germplasm conservation, precision breeding, and genetic improvement in P. japonicus. Full article

Background/Objectives: Neurodevelopmental disorders (NDDs) are genetically heterogeneous conditions with a complex molecular etiology involving numerous genes. Biallelic pathogenic variants in INTS1 cause a rare autosomal recessive NDD characterized by congenital cataracts, growth retardation, facial dysmorphism, and global developmental delay. To date, the clinical description of this disorder has been based solely on individual case reports, and its phenotypic spectrum remains incompletely defined. Methods: A 9-year-old female proband was evaluated for developmental delay, multiple congenital anomalies, and distinctive craniofacial features. Whole-exome sequencing (WES) was performed, followed by Sanger validation and segregation analysis. Variant pathogenicity was assessed using in silico prediction tools and 3D protein structural modeling. Results: Whole-exome sequencing identified two novel compound heterozygous missense variants in INTS1, c.1145G>A (p.Arg382Gln) and c.1195G>A (p.Gly399Ser), both located in exon 9. Segregation analysis showed that c.1145G>A was inherited from the father and c.1195G>A from the mother, and both variants are extremely rare in population databases. Conclusions: We report a patient carrying novel biallelic INTS1 variants, whose clinical presentation differs from previously reported cases, including those with milder phenotypes characterized by preserved speech development and absence of intellectual disability. This observation broadens the clinical spectrum of INTS1-related disease and underscores its phenotypic heterogeneity. Full article

Mugalzhar horses are a relatively young native breed of Kazakhstan, prized for meat and milk production and adaptation. This study was conducted to investigate genetic diversity and pinpoint genomic regions associated with selection signatures in this breed using whole-genome sequence data. Variant calling yielded a total of 21,722,393 high-quality variants, including 19,495,163 SNPs and 2,227,230 indels. Most variants were located in introns and intergenic regions, while only 1.94% were exonic. Estimates of genetic diversity were moderate, with expected and observed heterozygosity and nucleotide diversity of 0.2325, 0.2402, and 0.0021, respectively. We identified nine adaptive candidate genes (SCAPER, FHAD1, MMP15, ADGRE1, CMKLR1, MRPL15, ZNF667, CCDC66, and LOC100055310), harboring high-impact exonic variants in the homozygote state for an alternative allele. No deleterious segregating variants associated with Mendelian traits were found in this population, while seven variants linked to coat color and gaitedness were detected in a low frequency heterozygous state. Our findings suggest that there are certain genomic regions subjected to ancient selection footprints during the ancestor breed formation and adaptation. The outcome of this study serves as a foundation for future genomic-driven strategies, a broader utilization of this breed, and a reference for genomic studies on other horse breeds. Full article

Background/Objectives: Hereditary hearing loss (HHL) is a genetically heterogeneous condition, involving more than 150 genes in non-syndromic cases and associated with over 400 distinct disorders in syndromic forms. Although whole-exome sequencing (WES) has markedly increased diagnostic yield, a substantial number of cases remain unsolved, often due to intronic variants that affect splicing and are difficult to interpret. This study aimed to characterize the potential impact of intronic variants predicted to alter splicing in families affected by HHL. Methods: The effect of seven intronic variants, previously identified in a diagnostic setting by WES within ADGRV1, ATP11A, GSDME, OTOF, OTOGL, and USH2A genes, was evaluated. To functionally validate these predictions, in vitro minigene splicing assays were subsequently performed. Results: All the identified variants were predicted to disrupt normal RNA splicing. The functional studies with minigene assays confirmed this observation and showed that the tested variants induced both exon skipping and activation of cryptic splice sites. In five out of seven cases, these splicing alterations caused a frameshift and introduced a premature termination codon, ultimately resulting in nonsense-mediated mRNA decay and protein degradation. Conclusions: This study expands the mutational spectrum of HL-related genes and highlights the importance of integrating in silico predictions with minigene assays. Such a combined approach is crucial for accurate interpretation of splicing variants, particularly when patient-derived RNA samples are unavailable. Full article

Background: DNA methylation, as an epigenetic modification, is crucial in the regulatory mechanism of salt resistance in plants. Methods: To gain deeper insight into the relationship between DNA methylation and mRNA exons in halophytes and their potential roles in regulating salt tolerance, this study employed whole-genome bisulfite sequencing (WGBS) and transcriptome sequencing data to analyze the leaves of the halophyte Paspalum vaginatum, widely distributed in tropical regions. Results: The findings revealed that the methylation level of 5-methylcytosine (5mC) in the genomic elements of P. vaginatum increased with prolonged salt treatment under salt stress conditions. This observation suggested that the methylation level plays a pivotal role in the salt stress response of P. vaginatum. Notably, under salt stress, the number of variants at the mRNA exon level was significantly higher than that at the DNA level. Furthermore, comparative analysis revealed sequence variants within exonic regions of mature mRNA transcripts for several genes in salt-treated samples relative to pre-stress controls, and these changes were found to be enriched in several salt-tolerance pathways, including unsaturated fatty acid metabolism and ascorbic acid metabolism, among others. Further analysis demonstrated that the occurrence of these variants changed concomitantly with the dynamic changes in CG methylation levels in the gene body of some salt-tolerant genes. Therefore, it was speculated that mRNA exon variations probably promoted the elevation of CG 5mC methylation levels at the DNA level under salt stress conditions, further enabling the plant to adapt to the salt-stress environment. Conclusions: These findings offer preliminary insights into the relationship between DNA methylation and mRNA exon variations in P. vaginatum under salt stress, providing valuable information and avenues for further investigation into the regulatory role of mRNA in DNA methylation. Full article

Background/Objectives: While complete loss-of-function (LoF) SPINK1 variants in the simple heterozygous state cause chronic pancreatitis, biallelic complete LoF variants result in a rare pediatric disorder termed severe infantile isolated exocrine pancreatic insufficiency (SIIEPI). To date, only two individuals with a null SPINK1 genotype have been reported—one homozygous for a whole-gene deletion and the other for an Alu insertion in the 3′ untranslated region. Here, we report the genetic basis of a third SIIEPI case, presenting in early infancy with severe exocrine pancreatic insufficiency and diffuse pancreatic lipomatosis. Methods: Targeted next-generation sequencing (NGS) was used to analyze the entire coding region and exon–intron boundaries of the SPINK1 gene. Copy number variant (CNV) analysis was performed with SeqNext, based on normalized amplicon coverage. Results: The proband harbored compound heterozygous complete LoF SPINK1 variants. One was the known NM_001379610.1:c.180_181del (p.(Cys61PhefsTer2)), inherited from the father. The second, initially detected as an exon 2 deletion and confirmed by quantitative fluorescent multiplex PCR (QFM-PCR), was further characterized by long-range PCR as a complex rearrangement comprising a 1185 bp deletion removing exon 2, a 118 bp templated insertion followed by a non-templated nucleotide, and an 8 bp deletion. The mutational signature is consistent with serial replication slippage or template switching involving translesion synthesis. This maternally inherited variant has not been previously reported. Conclusions: This study expands the mutational spectrum of SPINK1-related SIIEPI and suggests that this distinct pediatric disorder may be under recognized in clinical practice. Full article

Background/Objectives: Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder with a multifactorial pathogenesis and a well-established genetic component. While pathogenic variants in genes such as ABCB4 and ABCB11 are implicated in a subset of cases, many remain genetically unexplained. This study aimed to investigate the genetic background of ICP in a multi-generational family with recurrent hepatobiliary disease. Methods: Whole-exome sequencing was performed on the proband and five female relatives. Variant filtering prioritized rare, exonic or splice-site variants predicted to undergo damage by in silico tools and which were present in all affected family members. Identified variants were assessed using population databases and compared with a control group of 433 unrelated women with uncomplicated pregnancies. Variant confirmation was performed using Sanger sequencing and high-resolution melting analysis. Results: No pathogenic variants were identified in known ICP-associated genes. However, a rare heterozygous missense variant in ABCB5 (c.1610G>A; p.Arg537His; rs779950110) was found in all affected individuals and two younger female relatives. This variant is exceedingly rare in population databases, absent in controls, and predicted to be pathogenic by multiple algorithms. ABCB5, although not previously linked to ICP, is an ATP-binding cassette transporter expressed in various tissues, including liver compartments. Conclusions: This study reports a novel ABCB5 variant segregating with ICP and early-onset hepatobiliary disease in a family. These findings suggest ABCB5 as a potential new susceptibility gene in ICP, warranting further functional investigation. Full article

Background: Congenital diarrhea is persistent diarrhea that manifests during the neonatal period. Mutations in DGAT1, which is crucial for triglyceride synthesis and lipid absorption in the small intestine, are causal factors for congenital diarrhea. In this study, we aimed to determine the value of tissue RNA sequencing (RNA-seq) for assisting with the clinical diagnosis of some genetic variants of uncertain significance. Methods: We clinically evaluated a patient with watery diarrhea, vomiting, severe malnutrition, and total parenteral nutrition dependence. Possible pathogenic variants were detected using whole-exome sequencing (WES). RNA-seq was utilized to explore the transcriptional alterations in DGAT1 variants identified by WES with unknown clinical significance, according to the American College of Medical Genetics guidelines. Systemic examinations, including endoscopic and histopathological examinations of the intestinal mucosa, were conducted to rule out other potential diagnoses. Results: We successfully diagnosed a patient with congenital diarrhea and protein-losing enteropathy caused by a DGAT1 mutation and reviewed the literature of 19 cases of children with DGAT defects. The missense mutation c.620A>G, p.Lys207Arg located in exon 15, and the intronic mutation c.1249-6T>G in DGAT1 were identified by WES. RNA-seq revealed two aberrant splicing events in the DGAT1 gene of the patient’s small intestinal tissue. Both variants lead to loss-of-function consequences and are classified as pathogenic variants of congenital diarrhea. Conclusions: Rare DGAT1 variants were identified as pathogenic evidence of congenital diarrhea, and the detection of tissue-specific mRNA splicing and transcriptional effects can provide auxiliary evidence. Full article

Background: Hemiplegic migraine (HM) is a rare and severe subtype of migraine with a complex genetic basis. Although pathogenic variants in CACNA1A, ATP1A2, and SCN1A explain some familial cases, a significant proportion of patients remain genetically undiagnosed. Increasing evidence points to an overlap between migraine and cerebral small vessel disease (SVD), implicating vascular dysfunction in HM pathophysiology. Objective: This study aimed to identify rare or novel variants in genes associated with SVD in a cohort of patients clinically diagnosed with HM who tested negative for known familial hemiplegic migraine (FHM) pathogenic variants. Methods: We conducted a case-control association analysis of whole exome sequencing (WES) data from 184 unrelated HM patients. A targeted panel of 34 SVD-related genes was assessed. Variants were prioritised based on rarity (MAF ≤ 0.05), location (exonic/splice site), and predicted pathogenicity using in silico tools. Statistical comparisons to gnomAD’s Non-Finnish European population were made using chi-square tests. Results: Significant variants were identified in several SVD-related genes, including LRP1 (p.Thr4077Arg), COL4A1 (p.Pro54Leu), COL4A2 (p.Glu1123Gly), and TGFBR2 (p.Met148Leu and p.Ala51Pro). The LRP1 variant showed the strongest association (p < 0.001). All key variants demonstrated pathogenicity predictions in multiple computational models, implicating them in vascular dysfunction relevant to migraine mechanisms. Conclusions: This study provides new insights into the genetic architecture of hemiplegic migraine, identifying rare and potentially deleterious variants in SVD-related genes. These findings support the hypothesis that vascular and cellular maintenance pathways contribute to migraine susceptibility and may offer new targets for diagnosis and therapy. Full article

Excavating new salt tolerance genes and utilizing them to improve salt-tolerant wheat varieties is an effective way to utilize salinized soil. The NAC gene family plays an important role in plant response to salt stress. In this study, 446 NAC sequences were isolated from the whole genome of common wheat and classified into 118 members based on subgenome homology, named TaNAC1 to TaNAC118. Transcriptome analysis of salt-tolerant wheat breeding line CH7034 roots revealed that 144 of the 446 TaNAC genes showed significant changes in expression levels at least two time points after NaCl treatment. These differentially expressed TaNACs were divided into four groups, and Group 4, containing the largest number of 78 genes, exhibited a successive upregulation trend after salt treatment. Single nucleotide polymorphisms (SNPs) of the TaNAC gene family in 114 wheat germplasms were retrieved from the public database and were subjected to further association analysis with the relative salt-injury rates (RSIRs) of six root phenotypes, and then 20 SNPs distributed on chromosomes 1B, 2B, 2D, 3B, 3D, 5B, 5D, and 7A were correlated with phenotypes involving salt tolerance (p < 0.0001). Combining the results of RT-qPCR and association analysis, we further selected three NAC genes from Group 4 as candidate genes that related to salt tolerance, including TaNAC26-D3.2, TaNAC33-B, and TaNAC40-B. Compared with the wild type, the roots of the tanac26-d3.2 mutant showed shorter length, less volume, and reduced biomass after being subjected to salt stress. Four SNPs of TaNAC26-D3.2 formed two haplotypes, Hap1 and Hap2, and germplasms with Hap2 exhibited better salt tolerance. Snp3, in exon 3 of TaNAC26-D3.2, causing a synonymous mutation, was developed into a Kompetitive Allele-Specific PCR marker, K3, to distinguish the two haplotypes, which can be further used for wheat germplasm screening or marker-assisted breeding. This study provides new genes and molecular markers for improvement of salt tolerance in wheat. Full article

While prime editing offers improved precision compared to traditional CRISPR-Cas9 systems, concerns remain regarding potential off-target effects, including epigenetic changes such as DNA methylation. In this study, we investigated whether prime editing induces aberrant CpG methylation patterns. Whole-genome bisulfite sequencing revealed overall methylation similarity between Cas9-edited, and PE2-edited cells. However, localized epigenetic changes were observed, particularly in CpG islands and exon regions. The PE2-edited group showed a higher proportion of differentially methylated regions (DMRs) in some coding sequences compared to controls and Cas9-edited samples. Notably, CpG island methylation reached 0.18% in the PE2 vs. Cas9 comparison, indicating a higher susceptibility of these regulatory elements to epigenetic alterations by prime editing. Molecular function analyses including Gene Ontology and KEGG pathway analyses further revealed enrichment in molecular functions related to transcriptional regulation and redox activity in PE2-edited cells. These findings suggest that prime editing, while precise, may introduce subtle but functionally relevant methylation changes that could influence gene expression and cellular pathways. In summary, prime editing can induce localized DNA methylation changes in human cells, particularly within regulatory and coding regions. Understanding these epigenetic consequences is critical for the development of safer and more effective therapeutic applications of genome editing technologies. Full article