Migraine is a complex neurological disorder, and the most common migraine categories are migraine with aura and without aura. The higher prevalence of migraine in related individuals compared to the general population indicates a potential genetic predisposition; however, gene expression, which is influenced by both genetic and environmental factors, can also be a major factor in the migraine susceptibility. Given the high number of Portuguese migraine patients whose diagnosis and treatment have not yet been well established, we decided to carry out a whole transcriptome analysis within a migraine Portuguese cohort. This study aims to identify potential biomarkers that could contribute to improved migraine therapy. We performed total RNA sequencing on whole blood samples from 15 migraine patients and 12 age-matched controls. Differential expression analysis and gene set enrichment analysis were performed in different migraine subgroups. Finally, we performed the protein-protein interaction networks of differentially expressed genes. Gene set enrichment analysis comparing migraine patients with controls highlighted upregulated pathways linked to metabolism, and downregulated immuno-inflammatory pathways. Moreover, the groups of female migraine patients and female migraine without aura patients emphasized significant upregulated pathways, including G protein-coupled receptors signalling pathways, when compared with female controls. Interestingly, we found two important differentially expressed genes related to parathyroid hormone: PTH1R and PTH2. PTH1R was upregulated in female migraine without aura versus female controls, while PTH2 was both upregulated between female migraine patients and female controls, as well as between female migraine without aura and controls. Here, we show, for the first time, the involvement of parathyroid hormone receptors and their associated gene expression patterns in female migraine patients. These molecules stand out as sturdy and promising biomarkers for innovative therapeutic in female migraine patients.

Oral cancer is a malignant disease with a notably high incidence rate in Taiwan. Recent reports have revealed that MIR155HG polymorphisms play a crucial role in the development of tumorigenesis in human cancers. The objective of this study was to investigate the role of MIR155HG polymorphisms in susceptibility to oral cancer among individuals in the Taiwanese Han population. In this study, we recruited 1316 oral cancer patients and controls to investigate the allelic discrimination of MIR155HG polymorphisms. Genotyping was performed using a TaqMan allelic discrimination test. The association of MIR155HG polymorphism rs1893650 with oral cancer susceptibility was found to be significant, unlike rs928883, rs767649, rs72014506, and rs4143370. Moreover, when compared to the homozygous TT genotype, the C alleles of rs1893650 polymorphism showed a significant correlation with cell differentiation grade in oral cancer patients (p = 0.019). Additionally, in oral cancer patients who chew betel quid, the C alleles of the rs1893650 polymorphism was significantly associated with lymph node metastasis and cell differentiation grade compared to those with the homozygous TT genotype. It was concluded that the rs1893650 polymorphism significantly increased the likelihood of developing oral cancer. Further large-scale studies involving diverse ethnic populations and clinicopathological characteristics are required to confirm these results. This research paves the way for new approaches in the detection and diagnosis of oral cancer, enabling early prevention of this disease.

Genetic diagnosis of ADPKD has been challenging due to the variant heterogeneity, presence of duplicated segments, and high GC content of exon 1 in PKD1. In our reproductive center, 40 patients were still genetically undiagnosed or diagnosed without single-nucleotide resolution after testing with a short-read sequencing panel in 312 patients with ADPKD phenotype. A combination of long-range PCR and long-read sequencing approach for PKD1 was performed on these 40 patients. LRS additionally identified 10 pathogenic or likely pathogenic PKD1 variants, including four patients with microgene conversion (c.160_166dup, c.2180T>C, and c.8161+1G>A) between PKD1 and its pseudogenes, three with indels (c.-49_43del, c.2985+2_2985+4del, and c.10709_10760dup), one with likely pathogenic deep intronic variant (c.2908-107G>A) and two with large deletions. LRS also identified nine PKD1 CNVs and precisely determined the breakpoints, while SRS failed to identify two of these CNVs. Therefore, LRS enables higher diagnostic yield of ADPKD and provides significant benefits for genetic counseling.

Reproductive performance in sheep plays a crucial role in determining the economic efficiency of the industry, with increasing litter size being a key focus for genetic improvement. The BMP15 gene is widely recognized as a major gene influencing sheep fertility. In this study, specific mutations in the BMP15 gene of Gobi short tail sheep were identified through direct sequencing, and these mutations were genotyped using the MassARRAY system. The g.54285159_54285161TTA indel was significantly associated with litter size in Gobi short tail sheep (p < 0.05). Three mutations, including g.54291460G>A, g.54288671C>T, and the g.54285159_54285161TTA indel, were significantly associated with litter size in Ujimqin sheep (p < 0.05). Furthermore, the promoter activity analysis demonstrated that the A allele exhibited significantly higher promoter activity compared to the G allele of the g.54291460G>A mutation. These findings highlight valuable genetic markers for improving sheep litter size and provide a robust theoretical foundation for further research on the BMP15 gene's role in reproduction.

Pathogenic variants in KIAA0586/TALPID3 are associated with the ciliopathy Joubert syndrome (JS). We report individuals with KIAA0586/TALPID3 variants affected by primary and motile cilia defects leading to JS and chronic destructive airway disease. DNA variants were detected in three families by sequencing. In two unrelated families, a deep-intronic variant (KIAA0586/TALPID3:c.3990 + 3186G>A) activated a cryptic exon. We performed histological and functional analyses in native and air-liquid interface (ALI) cultured respiratory cells. Primary cilia lengths were measured in patient-derived fibroblasts. Our data associate KIAA0586/TALPID3 variants with a syndrome combining JS and chronic destructive airway disease, reduced number of motile cilia, disorganized basal body location, and ciliary clearance malfunction. Additionally, patient-derived cell lines showed primary cilia defects. Disease causing KIAA0586/TALPID3 variants, including a deep-intronic sequence variant, were associated with primary and motile cilia defects in JS patients. The combination of JS and respiratory symptoms should be considered indicative for KIAA0586/TALPID3 sequence alterations.

Citrin deficiency (CD) is an autosomal recessive urea cycle disorder caused by biallelic loss-of-function variants in the SLC25A13 gene, leading to life-threatening hyperammonemia and hypoglycemia. Variants in deep introns can cause genetic diseases by altering splicing and are often missed by current diagnostic tools. Splice-switching oligonucleotides (SSOs) can resolve certain intronic variants, but patients harboring such variants need to be identified. We present a lean workflow from molecular diagnostics to SSO development to resolve splice-altering variants in deep introns that is applicable to other genetic disorders.

A deep intronic-gene panel was designed to identify deep intronic variants. SSOs were then developed and validated in vitro using a minigene assay and induced hepatocytes, and target engagement was verified in vivo by hydrodynamic tail vein injection of minigenes and SSOs.

With the deep intronic-gene panel and RNA analysis, we identified a novel SLC25A13 c.469-2922G>T variant that promotes the inclusion of a premature stop codon-containing pseudo-exon, SLC25A13-PE5, thereby causing CD. By a stepwise rational SSO design approach, we identified potent candidates inhibiting SLC25A13-PE5 at EC50 <2 nM in vitro. Upon conjugating the SSOs with GalNAc (N-acetylgalactosamine), they were validated to rescue normal protein expression and restore ureagenesis and ammonia clearance, key urea cycle functions, in patient-derived induced hepatocytes. In vivo on-target efficacy of the clinical GalNAc-SSO candidate, in the absence of acute toxicity and inflammation, was observed in a mouse model with exogenous hepatic minigene expression.

Our data validates a platform to redefine the molecular diagnosis of urea cycle disorders and provides proof-of-concept for a precision therapy for patients with CD, for whom the only effective treatment is liver transplantation.

Deep intronic variants are common causes of genetic diseases that are commonly neglected. In this study, we demonstrate an integrated precision diagnostic and therapeutic approach for urea cycle disorders. Specifically, we focus on citrin deficiency, going from the discovery of a novel splice variant in the SLC25A13 gene with our novel deep intronic-gene panel for urea cycle disorders, to the development and in vivo validation of an efficacious splice-switching oligonucleotide candidate for the pathogenic splice variant. We envision the possibility of extrapolating this pipeline to the diagnosis and development of treatments for other rare genetic diseases.

Junctional epidermolysis bullosa (JEB) is characterized by mucocutaneous fragility. We enrolled 69 cases of recessive JEB, with 13.0% of these cases remained genetically undiagnosed following an initial exome sequencing. Among cases carried COL17A1 variants, this proportion can reach 31.6%. We employed genome sequencing to genetically diagnosis these cases. Four deep intronic variants (c.4156+117 G > A, c.2039-104 G > A and c.1267+237dupC in the COL17A1 gene and c.-38 + 2 T > C in the LAMB3 gene) were identified in six cases. The c.4156+117 G > A variant was found in three of the five cases, suggesting it may be a common deep intronic variant in Chinese JEB. Splicing analysis revealed that these variants caused splicing defect by inducing exon skipping, or pseudoexon insertion into the transcript in HaCaT cells, not in HEK293 cells. Our results emphasize the importance of selecting the right cell line for mRNA analysis.

Fabry disease (FD) is a lysosomal storage disorder resulting from mutations in the alpha-galactosidase A (GLA) gene, characterized by pain, skin lesions, renal failure, and cardiac disease. A 60-year-old proband was hospitalized for recurrent atrial fibrillation (AF) that was unresponsive to medication, with cardiac magnetic resonance imaging (CMRI) revealing left ventricular wall hypertrophy and fat infiltration. Whole-exome sequencing (WES) did not reveal any suspicious pathogenic variants. To further assess the diagnosis, endomyocardial biopsy (EMB) and electron microscopy were performed, revealing abundant zebra bodies in cardiomyocytes, consistent with FD. The diagnosis was ultimately confirmed by GLA enzyme activity analysis (<1.00). Further genetic investigations identified a deep intronic variant (c.640-814T>C) within the GLA gene. Minigene experiments demonstrated that this variant affected the splicing of GLA, resulting in the production of a truncated protein (p.Pro214SerfsTer10). Western blotting (WB) showed that the truncated protein was retained, while immunofluorescence (IF) analysis indicated partial lysosomal localization. In vitro assays confirmed that the retained protein was non-functional and exerted a dominant-negative effect on the normal GLA protein. Molecular docking analysis further revealed that the truncated protein could bind to the wild GLA monomer, significantly reducing cellular GLA enzyme activity. These findings indicate that, beyond being non-functional, the c.640-814T>C mutation may also exerts a dominant-negative effect that impairs the function of the wild GLA protein. These results highlight the importance of recognizing deep intronic mutations in the diagnosis and treatment of FD, contributing to a deeper understanding of the molecular mechanisms, enriching mutation databases, and providing insights into genotype-phenotype correlations.

As a complex disease, hypertension (HTN) is influenced by both genetic and environmental factors and their interaction. The calcium signaling pathway is known to be involved in the regulation of blood pressure, and dysfunction in this pathway may contribute to the development of hypertension. Genome-wide association studies (GWAS) have identified several genes in the calcium signaling pathway associated with susceptibility to HTN, including PLCB1, ATP2B1, and ADRB1. The aim of this study was to investigate the possible association between single nucleotide variants (SNVs) in the calcium signaling pathway and HTN.

We genotyped three SNVs: rs1801253 (ADRB1), rs6108168 (PLCB1), and rs17249754 (ATP2B1) in a population of 131 patients with hypertension and 115 healthy controls from Kermanshah province, Iran.

Our results showed a strong and significant association between the G allele and the GG and CG genotypes of the rs1801253 variant in the ADRB1 gene and susceptibility to hypertension. However, no significant association was found for the other two SNVs. In addition, the presence of the GCG haplotype (alleles from left to right: rs1801253, rs6108168, and rs17249754) appeared to confer a protective role against HTN.

This study has made a significant contribution towards enhancing the comprehension of hypertension development, as well as the early identification of individuals who are at risk.

Hypomyelinating leukodystrophy-5 (HLD5) is a rare autosomal recessive hypomyelination disorder characterized by congenital cataract, progressive neurologic impairment, and myelin deficiency in the central and peripheral nervous system, caused by mutations in the HYCC1 gene. Here we report a 23-year-old girl with HLD5 from unrelated families. Molecular analysis was performed using sequence screening of the HYCC1 gene. In addition, in silico prediction tools and molecular investigation were used to predict the structural effect of the mutations. Results showed a novel compound heterozygous mutation in the HYCC1 gene. Moreover, in silico tools and 3D structural modeling revealed that c.521C > A (p.Ala174Glu) and c.652C > G (p.Gln218Glu) mutations could affect the structure, stability, and conformational analyses in the N-ter domain of the Hyccin protein. We also, we compared the phenotype of our patient with those of previously reported cases with HLD5 syndrome and our findings indicate the absence of reliable genotype-phenotype correlations. To the best of our knowledge, this is the first report describing a Tunisian HLD5 patient with compound heterozygous mutations (c.521C > A (p.Ala174Glu) and c.652C > G (p.Gln218Glu)) in HYCC1 gene.

Cardiomyopathies are the most common heritable heart diseases in cats and humans. This study aimed to identify novel genetic variants in cats with hypertrophic cardiomyopathy (HCM) and restrictive cardiomyopathy (RCM) using a targeted panel of genes associated with human cardiomyopathy. Cats were phenotyped for HCM/RCM by echocardiography ± necropsy. DNA was extracted from residual blood, and targeted next-generation sequencing was performed on two separate feline cohorts: an across-breed cohort (23 healthy cats and 21 HCM-affected pedigree or Domestic Shorthair cats), and a within-breed cohort of Birman pedigree cats (14 healthy, 8 HCM-affected, and 6 RCM-affected). Genome Analysis Toolkit was used for variant discovery. Genomic association analyses, including the covariates breed, age, and sex, were conducted to identify genetic variants of interest. We identified genetic variants associated with both HCM and RCM susceptibility in the sarcomeric genes ACTC1, ACTN2, MYH7, TNNT2 and the non-sarcomeric gene CSRP3 in the Birman pedigree cats. These findings suggest that, as proposed in humans, there is at least partial overlap in the genetic background between the HCM and RCM phenotypes in cats. These findings offer potential insights for comparative cardiac research and translational medicine.

Oculocutaneous albinism type 1 is caused by variants in the TYR (tyrosinase) gene. We describe a family with two affected sibs who inherited the pathogenic missense TYR variant c.1146C > A;p.(Asn382Lys) from their mother and a deletion encompassing 65 kilobase pairs of the upstream region of the gene between hg38 coordinates chr11:89110944 and chr11:89175770, from their father. The deletion likely arose by non-homologous recombination since the regions including the two deletion breakpoints share no sequence homology. The deletion contains a single enhancer element that is homologous to a 5' Tyr core regulatory element in the mouse. A luciferase reporter assay showed that this element had a positive regulatory activity. This represents to our knowledge the first deletion solely restricted to non-coding upstream sequences of the TYR gene. It is assumed that the deletion down-regulates expression of the TYR gene and is therefore pathogenic, allowing to establish the diagnosis of OCA 1 in the patients. This study underscores the need to extend the search for pathogenic variants to regulatory regions either by whole genome sequencing or by targeted next generation sequencing of a panel including entire genes (exons, introns, flanking sequences) in order to improve the diagnostic rate in patients with albinism.

Background/Objectives: Tooth agenesis (TA) is a developmental anomaly prevalent in humans. It is particularly significant in children and adolescents because it is related to esthetic, physiological, and functional problems, including malocclusion, periodontal damage, and insufficient alveolar growth. WNT10A mutations have been identified as the main genetic alterations associated with tooth agenesis. Most previous studies have investigated WNT10A mutations in patients with tooth agenesis using single nucleotide polymorphism (SNP) arrays or exome sequencing. In this study, we conducted a comprehensive profiling of mutations within the exons and introns of WNT10A in Korean patients with non-syndromic tooth agenesis. Methods: Saliva samples were collected from Korean children and adolescents with non-syndromic tooth agenesis. Tagmentation-based sequencing was conducted to acquire mutation information for all exonic and intronic bases of the WNT10A gene. Results: Mutations were detected exclusively in the patient samples: 629C>G and 1100C>T in exon 1, 1977T>C in intron 1, 10256C>T and 10382G>A in exon 3, and 15953G>A in intron 4. Additional mutations were also observed at high ratios in the patient samples. Conclusions: The mutations identified in this study differ from previous findings. These results may provide useful information for understanding the pathogenicity of WNT10A mutations in Korean patients with tooth agenesis and support future diagnostic and therapeutic approaches.

Genomic variants causing abnormal splicing play important roles in genetic disorders and cancer development. Among them, variants that cause the formation of novel splice-sites (splice-site creating variants, SSCVs) are particularly difficult to identify and often overlooked in genomic studies. Additionally, these SSCVs are frequently considered promising candidates for treatment with splice-switching antisense oligonucleotides (ASOs). To leverage massive transcriptome sequence data such as those available from the Sequence Read Archive, we develop a novel framework to screen for SSCVs solely using transcriptome data. We apply it to 322,072 publicly available transcriptomes and identify 30,130 SSCVs. Among them, 5121 SSCVs affect disease-causing variants. By utilizing this extensive collection of SSCVs, we reveal the characteristics of Alu exonization via SSCVs, especially the hotspots of SSCVs within Alu sequences and their evolutionary relationships. We discover novel gain-of-function SSCVs in the deep intronic region of the NOTCH1 gene and demonstrate that their activation can be suppressed using splice-switching ASOs. Collectively, we provide a systematic approach for automatically acquiring a registry of SSCVs, which facilitates the elucidation of novel biological mechanisms underlying splicing and serves as a valuable resource for drug discovery. The catalogs of SSCVs identified in this study are accessible on the SSCV DB ( https://sscvdb.io ).

Clinical exome sequencing (ES) has facilitated genetic diagnosis in individuals with a rare genetic disorder by analysis of all protein-coding sequences in a single experiment. However, in 40-60% of patients, a conclusive diagnosis remains elusive. In 2-5% of these individuals, ES does identify a disease-associated monoallelic variant in a recessive disorder. We hypothesized that short-read genome sequencing (GS) might uncover a pathogenic variant on the second allele, thereby increasing diagnostic yield. We performed GS for 174 individuals in whom ES identified a monoallelic pathogenic variant in a gene associated with recessive disease related to their phenotype. GS interpretation was limited to the (non-)coding parts of the gene in which this first pathogenic variant was identified, focusing on splice-disrupting variants. Firstly, we uncovered a second pathogenic variant affecting coding sequence in five individuals, including two SNV/indel variants, two copy number variants, and one insertion. Secondly, for 24 individuals, we identified a total of 31 rare non-coding intronic SNV/indel variants, all predicted to disrupt splicing. Using functional follow-up assays, we confirmed an effect on splicing for three of these variants (in ABCA4, POLR3A and COL4A4) in three individuals. In summary, we identified a (likely) pathogenic second variant in 4.6% (8/174), and a possible diagnosis for 12.1% (21/174) of our cohort. Hence, when performing GS as first-tier diagnostic test, including the interpretation of SVs and rare intronic variants in known recessive disease genes, the overall diagnostic yield of rare disease will increase. The added diagnostic value of GS for recessive disease In our cohort of 174 individuals (84 males and 90 females) with a monoallelic pathogenic variant in genes associated with a wide and diverse range of recessive diseases (pie chart), using genome sequencing (GS) and a systematic approach (methods), we identified eight new diagnoses (4.6%). We identified a second likely pathogenic variant in eight individuals (results); In two a second coding variant was found, in three others, a rare non-coding SNV anticipated to disrupt splicing was uncovered, and in three individuals a structural rearrangement was identified (two copy number variants (CNV), and one structural variant (SV)).

High-throughput DNA sequencing has accelerated the discovery of disease-causing genetic variants, yet only in 10-40% of cases yield a genetic diagnosis. Increased implementation of genome sequencing has enabled a deeper exploration of the noncoding genome and recognition of noncoding variants as major contributors to disease. In a recent study, we identified a deep intronic variant in the AutoImmune REgulator (AIRE) gene (c.1504-818 G>A) as the cause of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), a life-threatening monogenic autoimmune disorder most often caused by biallelic AIRE defects. This deep intronic variant disrupts normal splicing AIRE , causing pseudoexon inclusion and altered protein function. By developing an antisense oligonucleotide (ASO) targeting the pseudoexon sequence, we restored normal AIRE transcript in vitro, thereby revealing a potential genotype-specific candidate treatment. Our study illustrates key aspects of intronic variant detection, validation, and candidate ASO development. Herein, we briefly highlight the growing potential of ASO-based therapies for deep intronic variants, addressing the unmet need of personalized, genotype-specific therapies in diseases lacking curative options.

Meier-Gorlin syndrome (MGORS) is a rare autosomal inherited form of primordial dwarfism. Pathogenic variants in 13 genes involved in DNA replication initiation have been identified in this disease, but homozygous intronic variants have never been reported. Additionally, whether growth hormone (GH) treatment can increase the height of children with MGORS is unclear.

The medical history data of a young girl were collected and reviewed. Whole-exome sequencing (WES) and bioinformatic analysis were performed to identify any variants and predict their pathogenicity. Minigene constructs were generated and transfected into HEK-293T cells for in vitro splicing assays. The literature was reviewed to explore the mutational spectrum and efficacy of GH treatment for this disease.

A girl with microtia, hypoplastic patellae, and severe growth retardation carried a novel homozygous intronic variant (NM_030928.4: exon 3: c.352-30 A > C) in CDT1. The variant was predicted to break a branch point and alter splicing, and the minigene assay confirmed abnormal splicing with exon 3 skipping. The patient was treated with GH for 5 years, with an increase in growth velocity from 4.0 cm/year to an average of 6.2 cm/year. A literature review revealed that the most common variant type and inheritance state were missense and compound heterozygous, respectively. Additionally, the vast majority of children with MGORS treated with GH had normal insulin-like growth factor 1 (IGF-1) levels, and half of them responded positively to GH therapy.

We reported a novel pathogenic homozygous intronic variant (c.352-30 A > C) of CDT1 in a girl with MGORS, and this mutation extended the genetic spectrum of the disease. GH therapy may be beneficial for height outcomes in children with MGORS with normal IGF-1 levels.

The early diagnosis and appropriate treatment of monogenic glomerular diseases can reduce kidney failure, avoid unnecessary investigations such as kidney biopsies and ineffective treatment with immunosuppressants, guide transplant decisions, and inform the genetic risks of their family members. Yet, genetic testing for kidney disease is underutilized in Singapore. We aimed to implement a nephrologist-led genetic service and evaluate the acceptance, adoption, utility, and cost-effectiveness of genetic testing for monogenic glomerular disease in Singapore.

We will perform a prospective, multi-centre, type II hybrid effectiveness-implementation study with a post-design to evaluate both implementation and clinical outcomes of nephrologist-led genetic testing for suspected genetic glomerular kidney diseases. The multi-disciplinary implementation team will train "genetic nephrologists" to provide pre- and post-test counselling, order targeted exome panel sequencing for suspected glomerular kidney diseases (persistent microscopic haematuria and/or albuminuria or proteinuria in the absence of known causes, steroid-resistant primary nephrotic syndrome, apparent familial IgA nephropathy, or chronic kidney disease with no apparent cause), and interpret genetic test results; create workflows for patient referral, evaluation and management, and discuss genetic results at regular genomic board meetings. The outcomes are acceptance, appropriateness and adoption among patients and nephrologists, utility (proportion of patients who received genetic testing and have a confirmed diagnosis of genetic glomerular disease), and cost-effectiveness.

This study will create and evaluate a nephrologist-led genetic service, develop an efficient variant curation process, and inform future recommendations on the optimal referral and genetic testing strategy for monogenic glomerular disease in Singapore. This will facilitate the future mainstreaming of genetic testing that will enable precision medicine in kidney care.

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.

Individuals with HIV experience an increased risk of lymphoma, making this an important cause of death among people with HIV. Nevertheless, little is known regarding the underlying genetic aberrations, which we therefore set out to characterize.

We conducted next-generation panel sequencing to explore the mutational status of diagnostic lymphoma biopsies from 18 patients diagnosed with lymphoma secondary to HIV infection.

Ion Torrent next-generation sequencing was performed with an AmpliSeq panel on diagnostic lymphoma biopsies from HIV-associated B-cell lymphomas ( n  = 18), comprising diffuse large B-cell lymphoma ( n  = 9), classic Hodgkin lymphoma ( n  = 6), Burkitt lymphoma ( n  = 2), follicular lymphoma ( n  = 1), and marginal zone lymphoma ( n  = 1). The panel comprised 69 lymphoid and/or myeloid-relevant genes, in which either the entire coding sequence or a hotspot region was sequenced.

Among the 18 lymphomas, we detected 213 variants. The number of detected mutations ranged from 4 to 41 per tumor distributed among 42 genes, including both exonic and intronic regions. The most frequently mutated genes included KMT2D (67%), TNFAIP3 (50%), and TP53 (61%). Notably, no gene was found to harbor variants across all the HIV-associated lymphomas, nor did we find subtype-specific variants. While some variants were shared among patients, most were unique to the individual patient and were often not reported as malignant genetic variants in databases.

Our findings demonstrate genetic heterogeneity across histological subtypes of HIV-associated lymphomas and thus help elucidate the genetics and pathophysiological mechanisms underlying the disease.

Wilms tumor 1 (WT1; NM_024426) causes Denys-Drash syndrome, Frasier syndrome, or isolated focal segmental glomerulosclerosis. Several WT1 intron variants are pathogenic; however, the pathogenicity of some variants remains undefined. Whether a candidate variant detected in a patient is pathogenic is very important for determining the therapeutic options for the patient.

In this study, we evaluated the pathogenicity of WT1 gene intron variants with undetermined pathogenicity by comparing their splicing patterns with those of the wild-type using an in vitro splicing assay using minigenes. The three variants registered as likely disease-causing genes: Mut1 (c.1017-9 T > C(IVS5)), Mut2 (c.1355-28C > T(IVS8)), Mut3 (c.1447 + 1G > C(IVS9)), were included as subjects along the 34 splicing variants registered in the Human Gene Mutation Database (HGMD)®.

The results showed no significant differences in splicing patterns between Mut1 or Mut2 and the wild-type; however, significant differences were observed in Mut3.

We concluded that Mut1 and Mut2 do not possess pathogenicity although they were registered as likely pathogenic, whereas Mut3 exhibits pathogenicity. Our results suggest that the pathogenicity of intronic variants detected in patients should be carefully evaluated.

Primary familial brain calcification (PFBC) is a genetic neurological disease, yet no effective treatment is currently available. Here, we identified five novel intronic variants in SLC20A2 gene from six PFBC families. Three of these variants increased aberrant SLC20A2 pre-mRNA splicing by altering the binding affinity of splicing machineries to newly characterized cryptic exons, ultimately causing premature termination of SLC20A2 translation. Inhibiting the cryptic-exon incorporation with splice-switching ASOs increased the expression levels of functional SLC20A2 in cells carrying SLC20A2 mutations. Moreover, by knocking in a humanized SLC20A2 intron 2 sequence carrying a PFBC-associated intronic variant, the SLC20A2-KI mice exhibited increased inorganic phosphate (Pi) levels in cerebrospinal fluid (CSF) and progressive brain calcification. Intracerebroventricular administration of ASOs to these SLC20A2-KI mice reduced CSF Pi levels and suppressed brain calcification. Together, our findings expand the genetic etiology of PFBC and demonstrate ASO-mediated splice modulation as a potential therapy for PFBC patients with SLC20A2 haploinsufficiency.

The association between Wilson disease and various ATP7B mutations is well-established; however, the molecular mechanism underlying the functional consequence of these mutations, particularly the splicing mutations, remains unclear. This study focused on the ATP7B c.1543+1G>C variant, to reveal a universal pathogenic mechanism of the ATP7B mutants with altered N-terminus.

The splicing assay and RNA pull-down were performed to explore the mechanism of the aberrant splicing. The ATP7B knockout HuH-7 cell line and Atp7b-/- mice were created, and the functional consequence of the mutant ATP7B were evaluated in vitro and in vivo.

The c.1543+1G>C mutation resulted in the skipping of ATP7B exon 3, and the mutant ATP7B showed a loss of trans-Golgi network localization and was degraded via the ubiquitin-proteasome pathway, facilitated by enhanced interactions with COMMD1. Elevated intercellular copper concentration and reduced survival rate were observed in HuH-7 cells expressing mutant ATP7B. Restoration of wild-type ATP7B in Atp7b-/- mice resulted in a substantial improvement in phenotype, whereas mice treated with mutant ATP7B did not demonstrate equivalent benefits.

Our research investigated the pathogenicity and mechanism of ATP7B c.1543+1G>C variant, with particular focus on its enhanced interaction with COMMD1 as a potential universal mechanism contributing to the dysfunction of various ATP7B variants. These findings provide a foundation for the development of innovative therapeutic strategies that target abnormal splicing events in a range of hereditary diseases, including Wilson disease.

The search for genetic variants that act as causative factors in human diseases by disrupting the normal splicing process has primarily focused on single nucleotide variants (SNVs). It is worth noting that insertions or deletions (indels) have also been sporadically reported as causative disease variants through their potential impact on the splicing process. In this study, to perform identification of indels inducing exon extension/shrinkage events, we used individual-specific genomes and RNA sequencing (RNA-seq) data pertaining to the corresponding individuals and identified 12 exon extension/shrinkage events that were potentially induced by indels that disrupted authentic splice sites or created novel splice sites in 235 normal individuals. By evaluating the impact of these abnormal splicing events on the resulting transcripts, we found that five events led to the generation of premature termination codons (PTCs), including those occurring within genes associated with genetic disorders. Our analysis revealed that the potential functions of indels have been underexamined, and it is worth considering the possibility that indels may affect splice site usage, using RNA-seq data to discover novel potentially disease-associated mutations.

Beclin 1 protein encoded by the BECN1 gene plays a critical role in the autophagy pathway which is utilized by the Hepatitis B virus (HBV) for its replication. HBV is known for the subversion of the host's autophagy process for its multiplication. The aim of this study was to determine the role of BECN1 intronic variants in HBV susceptibility. Intronic region variant rs9890617 was analyzed using Human splicing finder v3.1 and was found to alter splicing signals. A total of 712 individuals (494 HBV infected and 218 healthy controls) were recruited in the study and genotyped by applying Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). Statistical analysis revealed that the mutant allele T of rs9890617 was significantly associated with the overall disease risk in the allelic model (OR 1.41; 95%CI 1.00-1.99, p = 0.04). On stratifying the data based on the different stages of HBV infection, the mutant genotype showed a significant association with the chronic group in allelic (OR 1.62; 95%CI 1.11-2.39, p = 0.01), dominant (OR 1.64; 95%CI 1.07-2.52, p = 0.02), and co-dominant (OR 1.55; 95%CI 1.00-2.40, p = 0.04) models. Overall, this is the first study regarding beclin 1 variant rs9890617 and we found a significant association of the mutant T allele with the genetic predisposition to HBV infection.

Interpreting the clinical significance of putative splice-altering variants outside canonical splice sites remains difficult without time-intensive experimental studies. To address this, we introduce Parallel Splice Effect Sequencing (ParSE-seq), a multiplexed assay to quantify variant effects on RNA splicing. We first apply this technique to study hundreds of variants in the arrhythmia-associated gene SCN5A. Variants are studied in 'minigene' plasmids with molecular barcodes to allow pooled variant effect quantification. We perform experiments in two cell types, including disease-relevant induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). The assay strongly separates known control variants from ClinVar, enabling quantitative calibration of the ParSE-seq assay. Using these evidence strengths and experimental data, we reclassify 29 of 34 variants with conflicting interpretations and 11 of 42 variants of uncertain significance. In addition to intronic variants, we show that many synonymous and missense variants disrupted RNA splicing. Two splice-altering variants in the assay also disrupt splicing and sodium current when introduced into iPSC-CMs by CRISPR-Cas9 editing. ParSE-seq provides high-throughput experimental data for RNA-splicing to support precision medicine efforts and can be readily adopted to study other loss-of-function genotype-phenotype relationships.

Yao syndrome (YAOS) is formerly called nucleotide-binding oligomerization domain containing 2 (NOD2)-associated autoinflammatory disease.We report a large cohort of YAOS.

We conducted a retrospective analysis of a cohort of adult patients with systemic autoinflammatory diseases (SAIDs). All patients underwent testing for a periodic fever syndrome gene panel.

A total of 194 patients carried NOD2 variants, 152 patients were diagnosed with YAOS, and 42 had mixed autoinflammatory diseases with combined variants in NOD2 and other SAID-associated genes. Demographic, clinical and molecular data were summaried. In sub-group analysis of the 194 patients, individual patients were often identified to carry two or more variants that usually included IVS8 + 158/R702W, IVS8 + 158/L1007fs, IVS8 + 158/V955I, IVS8 + 158/other, or NOD2/variants in other SAID genes. Ninety-nine patients carried single variants. Taken together, these variants contribute to the disease in combination or individually.

This largest cohort has provided comprehensive clinical and genotyping data in YAOS. Variants in the NOD2 gene can give rise to a spectrum from inflammatory bowel disease to autoinflammatory disease.This report further raises awareness of the underdiagnosed disease in the medical community.

Multiple acyl-CoA dehydrogenase deficiency (MADD) is a rare inborn error of metabolism affecting fatty acid and amino acid oxidation with an incidence of 1 in 200,000 live births. MADD has three clinical phenotypes: severe neonatal-onset with or without congenital anomalies, and a milder late-onset form. Clinical diagnosis is supported by urinary organic acid and blood acylcarnitine analysis using tandem mass spectrometry in newborn screening programs. MADD is an autosomal recessive trait caused by biallelic mutations in the ETFA, ETFB, and ETFDH genes encoding the alpha and beta subunits of the electron transfer flavoprotein (ETF) and ETF-coenzyme Q oxidoreductase enzymes. Despite significant advancements in sequencing techniques, many patients remain undiagnosed, impacting their access to clinical care and genetic counseling. In this report, we achieved a definitive molecular diagnosis in a newborn by combining whole-genome sequencing (WGS) with RNA sequencing (RNA-seq). Whole-exome sequencing and next-generation gene panels fail to detect variants, possibly affecting splicing, in deep intronic regions. Here, we report a unique deep intronic mutation in intron 1 of the ETFDH gene, c.35-959A>G, in a patient with early-onset lethal MADD, resulting in pseudo-exon inclusion. The identified variant is the third mutation reported in this region, highlighting ETFDH intron 1 vulnerability. It cannot be excluded that these intronic sequence features may be more common in other genes than is currently believed. This study highlights the importance of incorporating RNA analysis into genome-wide testing to reveal the functional consequences of intronic mutations.

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare and most often severe genetic disease characterized by recurrent blistering and erosions of the skin and mucous membranes after minor trauma, leading to major local and systemic complications. The disease is caused by loss-of-function variants in COL7A1 encoding type VII collagen (C7), the main component of anchoring fibrils, which form attachment structures stabilizing the cutaneous basement membrane zone. Alterations in C7 protein structure and/or expression lead to abnormal, rare or absent anchoring fibrils resulting in loss of dermal-epidermal adherence and skin blistering. To date, more than 1,200 distinct COL7A1 deleterious variants have been reported and 19% are splice variants. Here, we describe two RDEB patients for whom we identified two pathogenic deep intronic pathogenic variants in COL7A1. One of these variants (c.7795-97C > G) promotes the inclusion of a pseudoexon between exons 104 and 105 in the COL7A1 transcript, while the other causes partial or complete retention of intron 51. We used antisense oligonucleotide (ASO) mediated exon skipping to correct these aberrant splicing events in vitro. This led to increased normal mRNA splicing above 94% and restoration of C7 protein expression at a level (up to 56%) that should be sufficient to reverse the phenotype. This first report of exon skipping applied to counteract deep intronic variants in COL7A1 represents a promising therapeutic strategy for personalized medicine directed at patients with intronic variants at a distance of consensus splice sites.

Albinism is a genetically heterogeneous disease in which 21 genes are known so far. Its inheritance mode is autosomal recessive except for one X-linked form. The molecular analysis of exonic sequences of these genes allows for about a 70% diagnostic rate. About half (15%) of the unsolved cases are heterozygous for one pathogenic or probably pathogenic variant. Assuming that the missing variant may be located in non-coding regions, we performed sequencing for 122 such heterozygous patients of either the whole genome (27 patients) or our NGS panel (95 patients) that includes, in addition to all exons of the 21 genes, the introns and flanking sequences of five genes, TYR, OCA2, SLC45A2, GPR143 and HPS1. Rare variants (MAF < 0.01) in trans to the first variant were tested by RT-PCR and/or minigene assay. Of the 14 variants tested, nine caused either exon skipping or the inclusion of a pseudoexon, allowing for the diagnosis of 11 patients. This represents 9.8% (12/122) supplementary diagnosis for formerly unsolved patients and 75% (12/16) of those in whom the candidate variant was in trans to the first variant. Of note, one missense variant was demonstrated to cause skipping of the exon in which it is located, thus shedding new light on its pathogenic mechanism. Searching for non-coding variants and testing them for an effect on RNA splicing is warranted in order to increase the diagnostic rate.