Intronic Regions Research Articles

RNA-First Approach Identifies Deep Intronic PHEX Variants in X-Linked Hypophosphatemic Rickets

Abstract Context Up to 20% of patients with X-linked hypophosphatemic rickets (XLH) have no causative variant identified on routine molecular diagnostic testing. Objective To identify intronic variants causing PHEX mis-splicing in patients with XLH. Setting The metabolic bone clinic of a paediatric orthopedic hospital. Participants Four patients (age 6 to 12 years; 3 girls) with clinically diagnosed XLH and no PHEX variant on routine testing. Main outcome measures RNA and DNA sequence analysis of PHEX. Methods Urine-derived cells were cultured, and mRNA was extracted and transcribed to cDNA. PHEX cDNA was amplified by PCR, followed by sequencing of PCR products. Sequencing of PHEX intronic DNA regions was performed to identify variants causing mis-splicing observed on RNA analysis. Results PHEX mis-splicing was identified in 3 of the 4 participants, and an intronic variant was identified in all 3 cases. In a 12-year-old boy, transcript analysis showed skipping of PHEX exon 13, while sequencing of PHEX intronic regions revealed a de novo 18 bp deletion in intron 13. In a 7-year-old girl, a pseudoexon in PHEX intron 17 was found, associated with a de novo deep intronic variant (c.1768+173A>G) that activated a cryptic splice donor site. Finally, an 84 bp pseudoexon in PHEX intron 21 caused by a recurrent de novo deep intronic variant (c.2147+1197A>G) was identified in an 11-year-old girl. Conclusions Analysis of RNA from urine-derived cells combined with sequencing of PHEX introns can identify deep intronic variants in individuals with XLH without a detectable PHEX variant in routine exon-centric molecular diagnosis.

Genome-wide methylation and transcriptome differential analysis of skeletal muscle in broilers with valgus-varus deformity

ABSTRACT 1. Valgus-varus deformity (VVD) is a disease that severely affects leg function in broilers and for which there is no effective control method current available. Although DNA methylation has an important impact on most physiological and pathological processes, its involvement in skeletal muscle growth and development in VVD broilers is unknown. In this study, genome-wide DNA methylation was analysed in VVD-affected and normal broilers using whole genome resulphite sequencing. 2. The results showed that in the cytosine-phosphoric acid-guanine (CG) sequence environment there was a methylation rate of about 55% and 4,265 differentially methylated regions (DMRs) were found in the CG. Of these, 550 were located in the promoter, 547 in the exon region, and 1,718 in the intron region. 3. All differentially methylated genes (DMGs) were analysed for enrichment of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The GO was enriched in pathways related to protein degradation such as proteasome complex, endopeptidase complex and extracellular region. The KEGG pathways were enriched in signalling pathways related to protein degradation and catabolism such as proteasome, nitrogen metabolism, adherens junction and alanine. 4. Protein interactions analysis revealed that FOS, MYL9, and FRAS1 had a high degree of interactions, in which the DNA methylation level of the MYL9 promoter region was negatively correlated with mRNA expression level. Further studies showed that 5-azacytidine (5-AzaC) inhibited DNMT1 and DNMT3A gene expression and promoted MYL9 expression. 5. This study systematically investigated overall DNA methylation patterns in the leg muscle of VVD and normal broilers. It screened common differential genes in conjunction with transcriptomic data to further identify genes associated with muscle growth and development. This study provides new insights to better understand the pathogenesis of VVD from an epigenetic perspective.

Novel HLA-DQB1, DQA1, DPA1 and DPB1 alleles identified in the Australian new south wales tissue typing laboratory

Introduction of NGS into clinical histocompatibility laboratories has greatly increased the frequency of novel HLA allele discovery. We identified 9 DQA1, 7 DQB1, 8 DPA1 and 2 DPB1 novel alleles over the last 2 years. 92% (24 of 26) differed from their closest allele by single nucleotide substitutions detected in coding regions and 84% (22 of 26) contained polymorphism outside of exon 2. Identification of novel alleles in non-coding intronic regions were restricted to splice sites. Two novel alleles arising from nucleotide substitution affecting splicing were identified and named with questionable expression status. Novel alleles with polymorphism detected only in non-coding regions (introns and UTRs) were not reported. 21 additional DQA1, DQB1 and DPA1 alleles detected in multiple individuals as novel at the time of testing, were also detected in other laboratories. The number of novel alleles detected further emphasises the role of NGS in novel allele discovery.

A MYB transcription factor underlying plant height in sorghum qHT7.1 and maize Brachytic 1 loci.

Manipulating plant height is an essential component of crop improvement. Plant height was generally reduced through breeding in wheat, rice, and sorghum to resist lodging and increase grain yield but kept high for bioenergy crops. Here, we positionally cloned a plant height quantitative trait locus (QTL) qHT7.1 as a MYB transcription factor controlling internode elongation, cell proliferation, and cell morphology in sorghum. A 740 bp transposable element insertion in the intronic region caused a partial mis-splicing event, generating a novel transcript that included an additional exon and a premature stop codon, leading to short plant height. The dominant allele had an overall higher expression than the recessive allele across development and internode position, while both alleles' expressions peaked at 46 days after planting and progressively decreased from the top to lower internodes. The orthologue of qHT7.1 was identified to underlie the brachytic1 (br1) locus in maize. A large insertion in exon 3 and a 160 bp insertion at the promoter region were identified in the br1 mutant, while an 18 bp promoter insertion was found to be associated with reduced plant height in a natural recessive allele. CRISPR/Cas9-induced gene knockout of br1 in two maize inbred lines showed significant plant height reduction. These findings revealed functional connections across natural, mutant, and edited alleles of this MYB transcription factor in sorghum and maize. This enriched our understanding of plant height regulation and enhanced our toolbox for fine-tuning plant height for crop improvement.

Syncope in Migraine: A Genome-Wide Association Study Revealing Distinct Genetic Susceptibility Variants Across Subtypes.

Syncope is characterized by the temporary loss of consciousness and is commonly associated with migraine. However, the genetic factors that contribute to this association are not well understood. This study investigated the specific genetic loci that make patients with migraine more susceptible to syncope as well as the genetic factors contributing to syncope and migraine comorbidity in a Han Chinese population in Taiwan. A genome-wide association study was applied to 1,724 patients with migraine who visited a tertiary hospital in Taiwan. The patients were genotyped using the Affymetrix Axiom Genome-Wide TWB 2.0 array and categorized into the following subgroups based on migraine type: episodic migraine, chronic migraine, migraine with aura, and migraine without aura. Multivariate regression analyses were used to assess the relationships between specific single-nucleotide polymorphisms (SNPs) and the clinical characteristics in patients with syncope and migraine comorbidity. In patients with migraine, SNPs were observed to be associated with syncope. In particular, the rs797384 SNP located in the intron region of LOC102724945 was associated with syncope in all patients with migraine. Additionally, four SNPs associated with syncope susceptibility were detected in the nonmigraine control group, and these SNPs differed from those in the migraine group, suggesting distinct underlying mechanisms. Furthermore, the rs797384 variant in the intron region of LOC102724945 was associated with the score on the Beck Depression Inventory. The novel genetic loci identified in this study will improve our understanding of the genetic basis of syncope and migraine comorbidity.

SRNAdeep: a novel tool for bacterial sRNA prediction based on DistilBERT encoding mode and deep learning algorithms

BackgroundBacterial small regulatory RNA (sRNA) plays a crucial role in cell metabolism and could be used as a new potential drug target in the treatment of pathogen-induced disease. However, experimental methods for identifying sRNAs still require a large investment of human and material resources.MethodsIn this study, we propose a novel sRNA prediction model called sRNAdeep based on the DistilBERT feature extraction and TextCNN methods. The sRNA and non-sRNA sequences of bacteria were considered as sentences and then fed into a composite model consisting of deep learning models to evaluate classification performance.ResultsBy filtering sRNAs from BSRD database, we obtained a validation dataset comprised of 2438 positive and 4730 negative samples. The benchmark experiments showed that sRNAdeep displayed better performance in the various indexes compared to previous sRNA prediction tools. By applying our tool to Mycobacterium tuberculosis (MTB) genome, we have identified 21 sRNAs within the intergenic and intron regions. A set of 272 targeted genes regulated by these sRNAs were also captured in MTB. The coding proteins of two genes (lysX and icd1) are implicated in drug response, with significant active sites related to drug resistance mechanisms of MTB.ConclusionIn conclusion, our newly developed sRNAdeep can help researchers identify bacterial sRNAs more precisely and can be freely available from https://github.com/pyajagod/sRNAdeep.git.

Relationship of Retroelements with Antiviral Proteins and Epigenetic Factors in Alzheimer's Disease

Genetic factors such as allelic variants of the PSEN1, PSEN2, APP, and APOE genes play an important role in Alzheimer's disease development. Still, they cannot explain all cases of the disease and cannot form the basis for effective treatment methods for the pathology. Alzheimer's disease is the most common neurodegenerative disease, so identifying new mechanisms of pathogenesis may reveal new ways of treating it. Since Alzheimer's disease is associated with aging, the hypothesis is proposed that an important trigger mechanism for it is the pathological activation of retroelements during aging, leading to epigenetic changes. This is due to the role of retroelements in gene expression regulation and the origin of long noncoding RNAs and microRNAs from transposons, changes in the expression of which are observed both during aging and Alzheimer's disease. Normally, activation of retroelements is observed in hippocampal neuronal stem cells, which is necessary for epigenetic programming during neuronal differentiation. Direct changes in the expression of retroelements in Alzheimer's disease have also been described. It has been suggested that aging is a trigger for the development of Alzheimer's disease due to the pathological activation of retroelements. To confirm this hypothesis, an analysis of specific microRNAs associated with Alzheimer's disease and aging in the MDTE DB (microRNAs derived from Transposable elements) database was conducted. As a result, identified expression changes in Alzheimer's disease of 37 individual microRNAs derived from retroelements (25 from LINE, 7 from SINE, 5 from HERV), of which 12 changes expression during physiological aging, which confirms my hypothesis that the activation of retroelements during physiological aging is a driver for Alzheimer's disease. This is evidenced by the defeat of diseases mainly by the elderly and older adults. Since 3 of the 12 miRNAs associated with aging and Alzheimer's disease originated from SINE/MIRs that evolved from tRNAs, the role of tRNAs and the tRFs and tRNA halves derived from them in the development of Alzheimer's disease, which are evolutionarily closely related to retroelements was described. These results are promising for targeted disease therapy in the mechanisms of RNA-directed DNA methylation with possible complex use of retroelement enzyme inhibitors. Additional evidence for the role of retroelements in the development of Alzheimer's disease is that overexpression of tau, which has antiviral properties, with its interaction with beta-amyloid leads to dysregulation of retroelements, and in tauopathies, activation of ERV is determined. At the same time, the effect of retroelements as inducers of proteinopathy and tau aggregation has been described. In addition, HIV and herpes viruses, which affect beta-amyloid and tau protein, are also activators of retroelements. Also, polymorphisms associated with Alzheimer's disease are located mainly in intronic and intergenic regions where retroelements are located, affecting changes in their activity.

Methylome of circulating cell free DNA as a novel biomarker tool: from acute coronary syndrome to broader risk stratification of cardiovascular disease

Abstract Background Cell death during tissue injury leads to release of chromosomal DNA which is promptly degraded. However, short DNA fragments wrapped around nucleosomes survive longer in the bloodstream and can be isolated as circulating cell-free DNA (ccfDNA). Oncology field pioneered the use of cfDNA as clinical biomarker by identifying sequence modifications induced in cancer cells. Importantly, ccfDNA also retains the same epigenetic information as the tissue of origin. Despite major advances for disease diagnosis and therapy, coronary artery diseases (CAD) and associated conditions such acute myocardial infarction (AMI) or heart failure (HF) are responsible for leading number of deaths worldwide. Preventive and surveillance strategies with non-invasive testing are needed. Purpose Evaluation of ccfDNA methylation profiles as prognostic non-invasive biomarker for risk stratification of acute coronary syndromes and their potential application in preventive and surveillance strategies in other cardiovascular disorders. Methods CcfDNA isolated from citrate-plasma collected from our discovery cohort, comprising healthy controls, STEMI, NSTEMI and unstable angina (UA) patients, was analyzed applying Whole Genome Bisulfite Sequencing (WGBS) using a low-input BS-seq (PBAT) protocol. Computational analysis generated differentially methylated regions (DMRs) by tiling CpG areas and setting a threshold of minimal 25% methylation difference compared to the healthy group. To assess the validity of our findings, a selection of disease-specific DMRs were tested using targeted methylation sequencing protocol in a new set of patients. This procedure consisted in enzymatic conversion of ccfDNA methylated sites followed by probe-specific enrichment libraries and sequencing at a Novaseq 6000 platform. Results The study identified a total of 1941 DMRs and from those 486 were STEMI, 223 NSTEMI and 684 UA specific. From the identified DMRs, 74.13% from STEMI, 72.68% from NSTEMI and 61.62% from UA annotated with heart-related diseases using DisGeNET gene-disease associations. Interestingly, most of identified DMRs located within intronic regions (~60%) and also annotated as enhancers and lncRNAs. The independent validation with targeted methylation sequencing identified 566, 306 and 248 DMRs, respectively, and reduced the number of disease-specific DMRs to 171 in STEMI, 115 in NSTEMI and 82 in UA. Conclusion and Future Approaches Methylation profiles of ccfDNA showed potential as a biomarker to stratify the severity of acute coronary syndromes, a novel non-invasive detection methodology that could be extrapolated to risk stratification in other cardiovascular disease such as heart failure or coronary artery disease.

Discovery of a cryptic founder variant in MYBPC3 associated with hypertrophic cardiomyopathy by promoting the most frequent natural missplicing events

Abstract Introduction MYBPC3 splicing errors are a common cause of hypertrophic cardiomyopathy (HCM). Most known actionable intronic variants are located near exons. However, genetic variants in deep intronic regions are also emerging as casuals factors of HCM. The previously undescribed variant MYBPC3 (NM_000256.3):c.2308+227G>A is not reported in gnomAD or dbSNP but is overrepresented in a cohort of probands with HCM from the same geographical area. This led us to suspect its clinical relevance despite the very low probability of being splice-altering as assigned by SpliceAI (Δ score = 0.03). Purpose To conduct a phenotypic and clinical description of the cohort, ascertain the pathogenicity of the variant, and investigate the existence of a common ancestor. Methods (1) Observational analysis of clinical data and familial evaluation results, (2) Functional study involving mRNA expression analysis in peripheral blood, along with in silico analysis of the splicing disruption mechanism, and (3) Haplotype analysis to evaluate the founder effect and assess the age of the mutation. Results MYBPC3:c.2308+227G>A was identified in 26 probands with HCM (69% male; mean age at diagnosis 53±10 years). Eighty relatives from 20 families were screened resulting in 17 cases diagnosed (mean age 49±19 years; 53% males), 19 positive genotype/negative phenotype and 38 non-carriers. The greatest cosegregation involved three cases carrying the variant, confirmed in four different families. Males were diagnosed at a younger age but without significant differences in clinical features or events during follow-up (table). RT-PCR expression analysis in patients' blood revealed that this variant disrupts pre-mRNA splicing by promoting the use of cryptic donor and acceptor splice sites, located downstream and upstream of the variant, respectively, which are already present in the intron 23 reference sequence. Strikingly, these cryptic splice sites represent one of the most frequent natural unannotated missplicing events in MYBPC3, as evidenced by SpliceVault analysis of high-throughput RNA sequencing databases. The direct primary event induced by the variant is expected to disrupt a regulatory RNA-protein binding site, thereby unblocking the use of preexisting cryptic splice sites and amplifying natural exonification missplicing events within intron 23 (figure). Finally, the haplotype analysis, based on the copy number of nine STRs covering a total of 29.2 Mb surrounding MYBPC3:c.2308+227G>A, revealed that 17 unrelated carriers shared a DNA segment of 10 Mb (10,067,150 bp). The origin of this mutation is estimated to be at least 82 generations ago and roughly 1649 years in the past (IC95%:1180-2300). Conclusions MYBPC3:c.2308+227G>A is an elusive novel deep intronic variant causing HCM by a molecular mechanism not previously described in this context. The founder effect of this variant is confirmed in our geographical area.Phenotypic and clinical characteristics

A splicing isoform of PD-1 promotes tumor progression as a potential immune checkpoint

The immune checkpoint receptor, programmed cell death 1 (PD-1, encoded by PDCD1), mediates the immune escape of cancer, but whether PD-1 splicing isoforms contribute to this process is still unclear. Here, we identify an alternative splicing isoform of human PD-1, which carries a 28-base pairs extension retained from 5′ region of intron 2 (PD-1^28), is expressed in peripheral T cells and tumor infiltrating lymphocytes. PD-1^28 expression is induced on T cells upon activation and is regulated by an RNA binding protein, TAF15. Functionally, PD-1^28 inhibits T cell proliferation, cytokine production, and tumor cell killing in vitro. In vivo, T cell-specific exogenous expression of PD-1^28 promotes tumor growth in both a syngeneic mouse tumor model and humanized NOG mice inoculated with human lung cancer cells. Our study thus demonstrates that PD-1^28 functions as an immune checkpoint, and may contribute to resistance to immune checkpoint blockade therapy.

Maternal e-cigarette exposure alters DNA methylome, site-specific CpG and CH methylation, and transcriptomic signatures in the neonatal brain

Maternal use of e-cigarette (e-cig) aerosols poses significant risks to fetal brain development, potentially increasing susceptibility to neurodevelopmental disorders in later life. However, the underlying mechanisms remain incompletely understood. This study aimed to understand the effects of fetal e-cig exposure on DNA methylome and transcriptomic changes in the neonatal brain. Pregnant rats were exposed to e-cig aerosols, and neonatal brains (5 males and 5 females/group) from both control and e-cig-exposed groups were used for experimental analysis. Results indicated that prenatal e-cig exposure altered site-specific DNA methylation patterns at both CpG and CH (non-CpG) sites, predominantly in intergenic and intronic regions, with sex dimorphism in methylation and gene expression changes. Gene ontology analysis revealed that e-cig exposure not only affected neuron projection development and axonogenesis but also altered pathways related to neurodegeneration and long-term depression. These findings provide novel insights into the dynamic changes of CpG and CH methylation induced by e-cig exposure, underscoring the susceptibility of the developing brain to maternal e-cig exposure and its potential implications for developmental disorders and neurodegenerative diseases later in life.

Genetic association study of preterm birth and gestational age in a population-based case-control study in Peru.

Preterm birth (PTB) affects ∼15 million pregnancies worldwide. Genetic studies have identified several candidate loci for PTB, but results remain inconclusive and limited to European populations. Thus, we conducted a genome-wide association study (GWAS) of PTB and gestational age at delivery (GA) among 2,212 Peruvian women. PTB cases delivered≥20 weeks' but < 37 weeks' gestation, while controls delivered at term (≥37 weeks but <42 weeks). Multivariable regressions were used to identify genetic markers for PTB and GA (∼6 million SNPs), adjusting for maternal age and the first two genetic principal components. In silico functional analysis was conducted among top signals detected with an arbitrary P < 1.0×10-5. We sought to replicate genetic markers for PTB and GA identified in Europeans, and we developed a genetic risk score for GA based on European markers. Mean GA was 30 ± 4 weeks in PTB cases (N = 933) and 39 ± 1 in the controls (N = 1,279). No associatiosn were identified at genome-wide level. Nominal PTB variants were enriched for biological pathways associated with polyketide, progesterone, steroid hormones, and glycosyl metabolism. Nominal GA variants were enriched in intronic regions and cancer pathways. Variants in WNT4 associated with GA in Europeans were replicated in our study. A genetic risk score was associated with a 2-day longer GA (P = 0.002) in our sample. This study identified various signals suggestively associated with PTB and GA in pregnant Peruvian women. None of these variants overlapped with signals previously identified in Europeans.

Variation in SSRs at different genomic regions and implications for the evolution and identification of Armillaria gallica.

Armillaria spp. are devastating forest pathogens. Due to its low pathogenicity and abundant genetic variation, Armillaria gallica exhibited a unique and beneficial symbiosis with Gastrodia elata, which was used as a traditional Chinese medicine. However, the variation and population structure of A. gallica populations have rarely been investigated. Hence, we analyzed the evolution and variation in simple sequence repeats (SSRs) in three Armillaria genomes: A. gallica, A. cepistipes, and A. ostoyae to assess the genetic diversity and population structure of 14 A. gallica strains. Genome analysis revealed that SSRs were more abundant in the intergenic region than the intron and exon region, as was the SSR density. Compared with other two genomes, SSR density was the lowest in exon region and largest in the intron region of A. gallica, with significant variation in genic region. There were 17 polymorphic markers in A. gallica genome was identified, with 26.7% in genic region, which is higher than that of 18.8% in the intergenic region. Moreover, a total of 50 alleles and 42 polymorphic loci were detected among these A. gallica strains. The averaged polymorphism information content (PIC) was 0.4487, ranged from 0.2577 to 0.6786. Both principal coordinate analysis (PCoA) and population structure analyses based on the genotype data of SSRs divided the strains into two clusters. The cluster I included all the strains from high-altitude G. elata producing areas and some low-altitude areas, while the strains in Cluster II originated from low-altitude G. elata producing areas. These results indicated that substantial genome-specific variation in SSRs within the genic region of A. gallica and provide new insights for further studies on the evolution and breeding of A. gallica.

Analysis of SLC genes alternative splicing identifies the SLC7A6 RI isoform as a therapeutic target for colorectal cancer.

Alternative splicing (AS), a crucial mechanism in post-transcriptional regulation, has been implicated in diverse cancer processes. Several splicing variants of solute carrier (SLC) transporters reportedly play pivotal roles in tumorigenesis and tumor development. However, an in-depth analysis of AS landscapes of SLCs in colon adenocarcinoma (COAD) is lacking. Herein, we analyzed data from The Cancer Genome Atlas and identified 1215 AS events across 243 SLC genes, including 109 differentially expressed AS (DEAS) events involving 62 SLC genes in COAD. Differentially spliced SLCs were enriched in biological processes, including transmembrane transporter activity, transporter activity, ferroptosis, and choline metabolism. In patients with COAD, tumor tissues exhibited higher expression of longer mitochondrial carrier SLC25A16 isoforms than adjacent normal tissues, consistent with bioinformatics analysis. Protein-coding sequences and transmembrane helices of survival-related DEAS were predicted, revealing that shifts in splicing sites altered the number and structure of their transmembrane proteins. We developed a prognostic risk model based on the screened 6-SLC-AS (SLC7A6_RI_37208 (SLC7A6-RI), SLC11A2_AP_21724, SLC2A8_ES_87631, SLC35B1_AA_42317, SLC39A11_AD_43204, and SLC7A8_AP_26712). Knockdown of the intronic region of SLC7A6-RI isoform enhanced colon cancer cell proliferation. Invivo, knockdown of the intronic region of SLC7A6-RI isoform enhanced tumor growth in colon cancer. Mechanistically, si-SLC7A6-RI isoform exerted oncogenic effects by activating the PI3K-Akt-mTOR signaling pathway and promoting cell proliferation, evidenced by increased expression of key regulators Phosphorylated Mammalian Target of Rapamycin (p-mTOR) and a cell proliferation marker Proliferating Cell Nuclear Antigen (PCNA) using western blotting. Our study elucidated SLC-AS in COAD, highlighting its potential as a prognostic and therapeutic target and emphasizing the suppressive influence of SLC7A6-RI in colon cancer progression.

Copy number variations in RNF216 and postsynaptic membrane-associated genes are associated with bipolar disorder: a case-control study in the Japanese population.

Bipolar disorder (BD) is a common psychiatric disorder characterized by alterations between manic/hypomanic and depressive states. Rare pathogenic copy number variations (CNVs) that overlap with exons of synaptic genes have been associated with BD. However, no study has comprehensively explored CNVs in synaptic genes associated with BD. Here, we evaluated the relationship between BD and rare CNVs that overlap with synaptic genes, not limited to exons, in the Japanese population. Using array comparative genome hybridization, we detected CNVs in 1839 patients with BD and 2760 controls. We used the Synaptic Gene Ontology database to identify rare CNVs that overlap with synaptic genes. Using gene-based analysis, we compared their frequencies between the BD and control groups. We also searched for synaptic gene sets related to BD. The significance level was set to a false discovery rate of 10%. The RNF216 gene was significantly associated with BD (odds ratio, 4.51 [95% confidence interval, 1.66-14.89], false discovery rate < 10%). The BD-associated CNV that corresponded with RNF216 also partially overlapped with the minimal critical region of the 7p22.1 microduplication syndrome. The integral component of the postsynaptic membrane (Gene Ontology:0099055) was significantly associated with BD. The CNV overlapping with the intron region of GRM5 in this gene set showed a nominal significant association between cases and controls (P < 0.05). We provide evidence that CNVs in RNF216 and postsynaptic membrane-related genes confer a risk of BD, contributing to a better understanding of the pathogenesis of BD.

Simultaneous Genotyping of Three SNVs, rs5471, rs5472, and rs2000999 Involved in Serum Haptoglobin Levels by Fluorescent Probe-Based Melting Curve Analysis.

Haptoglobin (Hp) is a hemoglobin-binding acute-phase serum protein. Several single nucleotide variations (SNVs) within the Hp gene (HP) or Hp-related protein gene (HPR), such as rs5471 (A>C) and rs5472 (A>G) in HP promoter region and rs2000999 (G>A) in intron 2 of HRP, are suggested to correlate with the serum Hp levels. To determine these three SNVs simultaneously, a genotyping assay based on duplex dual-labeled fluorescent probes was developed. The method was then validated by analyzing genomic DNA from 121 Ghanaian and two Japanese subjects who had been previously genotyped for rs5471, rs5472, and rs2000999. Both rs5471 and rs5472 could be determined as haplotypes with a single FAM-labeled fluorescent probe, and rs2000999 could be genotyped with a HEX-labeled fluorescent probe. The results obtained with the present method were consistent with the previous results except for those of three Ghanaian subjects. All three subjects appear to have multiple HPR copy number variants characteristic of African populations, which may have led to incorrect results during previous genotyping. This method allows us to genotype these three SNVs in a relatively large number of samples, especially in African populations where rs5471 is uniquely distributed.

A Rare Noncoding Enhancer Variant in SCN5A Contributes to the High Prevalence of Brugada Syndrome in Thailand.

Brugada syndrome (BrS) is a cardiac arrhythmia disorder that causes sudden death in young adults. Rare genetic variants in the SCN5A gene encoding the Nav1.5 sodium channel and common noncoding variants at this locus are robustly associated with the condition. BrS is particularly prevalent in Southeast Asia but the underlying ancestry-specific factors remain largely unknown. Genome sequencing of BrS probands and population-matched controls from Thailand was performed to identify rare noncoding variants at the SCN5A-SCN10A locus that were enriched in patients with BrS. A likely causal variant was prioritized by computational methods and introduced into human induced pluripotent stem cell (hiPSC) lines using CRISPR-Cas9. The effect of the variant on SCN5A expression and Nav1.5 sodium channel current was then assessed in hiPSC-derived cardiomyocytes (hiPSC-CMs). A rare noncoding variant in an SCN5A intronic enhancer region was highly enriched in patients with BrS (detected in 3.9% of cases with a case-control odds ratio of 45.2). The variant affects a nucleotide conserved across all mammalian species and predicted to disrupt a Mef2 transcription factor binding site. Heterozygous introduction of the enhancer variant in hiPSC-CMs caused significantly reduced SCN5A expression from the variant-containing allele and a 30% reduction in Nav1.5-mediated sodium current density compared with isogenic controls, confirming its pathogenicity. Patients with the variant had severe phenotypes, with 89% experiencing cardiac arrest. This is the first example of a functionally validated rare noncoding variant at the SCN5A locus and highlights how genome sequencing in understudied populations can identify novel disease mechanisms. The variant partly explains the increased prevalence of BrS in this region and enables the identification of at-risk variant carriers to reduce the burden of sudden cardiac death in Thailand.

Genetic Signatures: CD44 Single-Nucleotide Polymorphisms Affect Cell Surface Expression and Elevate Risk in Head and Neck Squamous Cell Carcinoma.

This study aimed to investigate the impact of single-nucleotide polymorphisms (SNPs) in the CD44 gene, specifically in the 3'UTR region (rs13347) and intronic region (rs187115), on the cell surface expression of CD44 protein and the risk of development of head and neck squamous cell carcinoma (HNSCC). The study involved analysis of 85 samples and 85 healthy controls. Immunohistochemistry (IHC) and flow cytometry were used to assess cell surface protein expression using CD44 antibody. DNA from formalin-fixed paraffin-embedded tissue sections was isolated and amplified using targeted primers. Sanger sequencing of the resultant amplified products was performed to determine the genotypes of the CD44 rs13347 and rs187115 SNPs. GTEx and RegulomeDB were queried to evaluate the genotypic effects of these variants on target gene expression and regulation. A comparison between patients with HNSCC and healthy controls revealed a significant association between CD44 rs13347 and an increased risk of HNSCC in all the analyzed models, especially the TT genotype showed a significantly higher risk with an odds ratio of 8.69 (95% CI, 2.35 to 32.09; P = .0003). However, no significant association was found between CD44 rs187115 and HNSCC in any of the models analyzed (all P > .05). Other notable findings included significant associations between CD44 rs13347 genotype and age (P = .031), number of CD44-positive tumor cells (P = .049), CD44 staining intensity (SI; P = .039), and CD44 immunoreactivity score (IRS) status (P = .019). The T allele and homozygous TT genotype of CD44 rs13347 SNP were associated with increased susceptibility to HNSCC and decreased proportion of CD44-positive tumor cells, low SI, and reduced IRS.

Patient-derived induced pluripotent stem cells to study non-canonical splicing variants associated with Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most prevalent inherited cardiomyopathy and a leading cause of sudden death. Genetic testing and familial cascade screening play a pivotal role in the clinical management of HCM patients. However, conventional genetic tests primarily focus on the detection of exonic and canonical splice site variation. Oversighting intronic non-canonical splicing variants potentially contributes to a proportion of HCM patients remaining genetically undiagnosed. Here, using a non-integrative reprogramming strategy, we generated induced pluripotent stem cell (iPSC) lines from four individuals carrying one of two variants within intronic regions of MYBPC3: c.1224-52G > A and c.1898-23A > G. Upon differentiation to iPSC-derived cardiomyocytes (iPSC-CMs), mis-spliced mRNAs were identified in cells harbouring these variants. Both abnormal mRNAs contained a premature termination codon (PTC), fitting the criteria for activation of nonsense mediated decay (NMD). However, the c.1898-23A > G transcripts escaped this mRNA quality control mechanism, while the c.1224-52G > A transcripts were degraded. The newly generated iPSC lines represent valuable tools for studying the functional consequences of intronic variation and for translational research aimed at reversing splicing abnormalities to prevent disease progression.

Clinico-Pathological Factors and AR-LBD Mutations in Early and Late Castration-Resistant Prostate Cancer.

Prostate cancer (PCa) is not well understood because of its enormous biological heterogeneity and unreliable progression. We conducted this retrospective analysis to examine the variables predicting early and late progression to castration-resistant PCa (CRPC) for better management of this disease. This single institutional retrospective study was conducted from January 2018 to January 2022. A total of 98 consecutive men meeting with the diagnosis of CRPC as per the inclusion criteria were included in the study and were stratified in four quartiles on the basis of time to CRPC (time to castration resistance [TTCR]) development. Early CRPC (1st quartile, TTCR = 6-12 months) and late CRPC (4th quartile, TTCR = 38-120 months) were then compared on the basis of different clinical, pathological and AR-LBD sequence to find the correlation with response duration. Median time to develop castration resistance was 25 ± 26.44 months. The mean age of the patients was 66.8 ± 9.20 years and median baseline PSA was calculated 100±685.06 ng/mL respectively. Higher Gleason score (≥7-10) was found to be significantly associated with early development of CRPC (p<0.001) and lower nadir PSA was significantly indicating late CRPC progression (p<0.005). No mutations were found in androgen receptor exon-5, 6, 7 except a homozygous mutation in the 7th intronic region, which is involved in splice variants formation playing noteworthy role in CRPC development. Time for metastatic PCa to CRPC ranges from 6-120 months revealing its heterogeneous nature. Early age presentation in the clinic and high initial PSA and high grade (GS>7) at diagnosis were positively associated with early CRPC while lower nadir PSA was correlated with late CRPC progression. No remarkable genomic mutations were discovered. Therefore, more data are needed and further research is required with large no. of patients to discover the predictive prognostic biomarkers for better patients' management.