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PubMed2026

Epidermolysis Bullosa Classification and Current Approach to Diagnosis.

Epidermolysis bullosa (EB) is a heterogeneous group of rare genodermatoses marked by skin fragility and bullae formation induced by minor trauma. Pathologic variants in at least 21 genes are associated with EB, grouped into four major subtypes based predominantly on the plane of cleavage within the skin. EB simplex is characterized by epidermal bullae formation and is due to gene mutations that affect epidermal proteins, most commonly keratin filaments. Junctional EB is due to gene mutations affecting proteins in the basement membrane zone, causing a split within the lamina lucida of the dermal-epidermal junction. Dystrophic EB is characterized by subepidermal bullae formation and is due to mutations in the gene encoding type VII collagen, which makes up the anchoring fibrils in the papillary dermis. Kindler EB is the rarest subtype and may be associated with cleavage at various levels within the skin due to a mutation in the FERMT1 gene causing defects in kindlin-1, a protein associated with integrins and focal adhesions. Because EB is such a heterogeneous disease, an understanding of genotype-phenotype correlations is necessary to help guide management. Traditionally, the first step in diagnosis was inducing a blister that was biopsied for immunofluorescence mapping. Currently, the gold standard for diagnosis is a blood sample or buccal swab for extraction of genomic DNA via next-generation sequencing, which can identify the exact causative gene. A diagnosis of EB is life altering for patients and families alike. A firm understanding of EB classification and initial diagnostic workup can help dermatologists feel empowered to support and counsel families.

Humans↗

PubMed2026

Solid tumours in RASopathies: insights from a large monocentric cohort and systematic review of the literature.

BACKGROUND: Dysregulation of the RAS-mitogen-activated protein kinase signalling pathway underlies RASopathies, a family of neurodevelopmental disorders associated with variable cancer predisposition. However, the prevalence and spectrum of solid tumours and the contribution of specific variants to tumour susceptibility remain poorly defined. METHODS: We assessed solid tumour prevalence and spectrum in the largest single-centre cohort of individuals with RASopathies (n=138), excluding neurofibromatosis type 1 and integrated these findings with a systematic literature review to evaluate tumour distribution and genotype-phenotype correlations. RESULTS: In our cohort, at least one solid tumour was identified in 10.8% of individuals with Noonan syndrome (NS), 47.8% with Costello syndrome (CS) and 7.3% with cardiofaciocutaneous syndrome (CFCS). Malignant tumours occurred in 5.4%, 30.4% and 2.4%, respectively. CS showed the highest tumour burden, frequently with multiple primary tumours, predominantly of the bladder. In NS, low-grade central nervous system (CNS) tumours were most common, particularly among individuals carrying PTPN11 variants. Tumour onset occurred with a median age of 19, 14 and 13 years in NS, CS and CFCS, respectively. Literature data analysis identified candidate variants in HRAS, PTPN11 and SOS1 genes associated with increased risk for solid tumours, which differed from mutational hotspots reported in childhood leukaemia or sporadic cancers. CONCLUSION: Solid tumour risk in RASopathies is syndrome-dependent and genotype-dependent, with CS showing a high burden of bladder tumours and NS mainly associated with CNS tumours. These findings may support tailored surveillance strategies.

Human Genetics↗

PubMed2026

An Update on Inborn Errors of V(D)J Recombination.

V(D)J recombination is the fundamental process by which developing T and B lymphocytes generate diverse antigen receptors, enabling adaptive immunity. This tightly regulated program operates exclusively in lymphoid precursors during G1 phase and depends on the lymphocyte-specific RAG1-RAG2 recombinase to introduce programmed DNA double-strand breaks at recombination signal sequences, followed by repair through the classical nonhomologous end joining (c-NHEJ) pathway. Disruption of any step in this molecular choreography compromises antigen receptor diversity and underlies a spectrum of inborn errors of immunity (IEIs), ranging from severe combined immunodeficiency (SCID) to immune dysregulation with autoimmunity and granulomatous disease. In this review, we place disorders of V(D)J recombination within the broader framework of T-cell development, detailing the temporal waves of recombinase activity, chromatin accessibility, and DNA damage responses that guide thymocyte differentiation. We discuss pathogenic variants affecting the cleavage phase [RAG1, RAG2, and the recently identified RAG cochaperone NudC domain-containing 3 (NUDCD3)], end processing (ARTEMIS), ligation and repair (LIG4, XLF, XRCC4, PRKDC), and genome surveillance pathways (ATM, MRN complex, RNF168), highlighting genotype-phenotype correlations and mechanisms driving immune deficiency and dysregulation. We briefly review recent diagnostic advances, including newborn screening using T-cell receptor excision circles, repertoire sequencing, and functional assays, alongside current therapeutic strategies. Finally, we outline key unanswered questions and argue that continued integration of clinical observation with molecular discovery is essential to improve outcomes and deepen understanding of adaptive immune development.

Humans↗

PubMed2026

Ancient DNA and Human Physiology.

Ancient DNA (aDNA) enables the reconstruction of chronologically sampled genomes from ancient humans, animals, plants, pathogens, and microorganisms, as well as environmental DNA, providing a record of biological changes through time. Improvements in short and degraded DNA extraction methods and low-cost sequencing now enable the generation of broad, cross-regional datasets that expand evolutionary analyses from past population demography to biological mechanisms. By tracking temporal shifts of allele frequencies, integrating functional genomics resources (e.g., gene expression, chromatin structure variation), modeling population demography to separate selection from genetic drift, and aligning genetic changes with archaeological, cultural, and climatic data, aDNA has the potential to link sequence variation to physiological function within their temporal and environmental contexts. In this review, we summarize illustrative case studies from aDNA research spanning complex traits, dietary adaptations, and responses to pathogens and other environmental changes, showing how human biology has evolved under multiple selective pressures through time. These dated signals help triage experimental work and expose mechanisms that are rare or absent in living cohorts. Although some challenges remain, such as geographic and temporal sampling disparities, limitations in data resolution and variant detection, and genotype-phenotype uncertainties, rapid methodological progress and stronger ethical frameworks are expanding what can be inferred, making aDNA a promising tool for refining physiological pathways, their timing, and their drivers.

Humans↗

PubMed2026

A Novel Splice Variant in the COL1A1 Gene Leads to Exon 46 Skipping and Osteogenesis Imperfecta.

BACKGROUND: Osteogenesis imperfecta (OI) is a clinical and genetic disorder characterised by bone fragility, growth deficiency and skeletal deformity. Ninety per cent of OI cases are attributable to autosomal dominant variants in the COL1A1 and COL1A2 genes. METHODS: Candidate variants were identified and verified through trio whole-exome sequencing (trio-WES), copy number variation sequencing (CNV-seq) and Sanger sequencing. Minigene splicing assays were performed in HeLa and HEK293T cells with pcDNA3.1 and pcMINI-C vectors to investigate the function of the candidate variants. A systematic review of COL1A1 splicing variants and the corresponding genotype-phenotype spectrum was performed. RESULTS: Trio-WES revealed a novel heterozygous variant in the C-terminal region of the COL1A1 gene: NM_000088.4:c.3423+5G>A. Sanger sequencing confirmed the variant in both the proband (II-2) and her foetus (III-1) who were clinically suspected of having OI. The c.3423+5G>A variant causes complete skipping of Exon 46, as demonstrated by a minigene splicing assay. We retrieved 419 COL1A1 splicing variants from PubMed, excluded 15 without phenotypic data and 2 linked to Ehlers-Danlos syndrome and stratified the remaining 402 variants into three types on the basis of splice site location: (1) Variants at canonical splicing sites (77.8%, 313/402) mostly cause mild phenotypes, whereas a minority may be severe. (2) Intron variants in other locations, such as splice region variants (17.9%, 72/402), usually cause mild clinical phenotypes, and deep intronic splice variants (0.4%, 2/402) that may result in severe phenotypes. (3) Other variants (3.7%, 15/402), such as exon variants or fragment loss, are extremely rare. We also preliminarily discuss the mechanisms underlying phenotypic variability and the characteristics of C-terminal variants. CONCLUSIONS: This intron variant in COL1A1 was classified as likely pathogenic and was confirmed to disrupt COL1A1 expression. The summary analysis results also revealed a correlation among splicing variants, C-terminal region variants and disease, suggesting that variant location provides a useful framework for prognosis prediction.

Female↗

PubMed2026

Pathogenic POLRMT variants in mice impair mtDNA transcription and affect perinatal survival.

Mitochondrial gene expression is essential for oxidative phosphorylation that generates the bulk of the cellular ATP, and mitochondrial dysfunction is a common cause of human metabolic diseases. Recently, the first pathogenic variants in the only known mitochondrial RNA polymerase (POLRMT) were described in patients presenting with a wide variety of clinical manifestations, including hypotonia, short stature, and developmental delay. Here, we modeled two human pathogenic POLRMT variants by creating the corresponding substitutions in mice: the dominant S582F and the recessive R984C variant. Mice homozygous for the R984C variant showed perinatal lethality without apparent embryonic developmental defects, a finding consistent with a failure to adapt to the metabolic transition to oxidative metabolism at birth. Mice carrying the S582F variant were viable and exhibited decreased mitochondrial transcript levels due to impaired de novo transcription. However, mtDNA levels and in organello mtDNA replication remained normal, which recapitulates the molecular phenotypes observed in patients. Altogether, our findings indicate that the conserved arginine near the active site is essential for POLRMT function, while the serine in the intercalating hairpin of the N-terminal domain is required for near-genome length transcription but not primase activity. This study highlights genotype-phenotype differences and provides new insights into POLRMT function.

Animals↗

PubMed2024

Identification of a novel EYA4 likely pathogenic variant in a Chinese family with postlingual non-syndromic hearing loss and analysis of molecular epidemiology of EYA4 variants.

BACKGROUND: EYA4 variants are responsible for DFNA10 deafness. Due to its insidious onset and slow progression, hearing loss in autosomal dominant non-syndromic hearing loss (ADNSHL) is usually challenging to detect early in clinical settings, with limited intervention options. Genetic testing can aid in early detection of hearing loss, enabling timely intervention to reduce disability rates and improve the quality of life. METHODS: In this study, we report the case of a Chinese family with postlingual and progressive hearing loss that was passed down for four generations. Whole-exome sequencing (WES) was performed on DNA samples from the proband. Candidate variants identified in the proband and family members were confirmed via Sanger sequencing. In silico prediction tools and co-segregation analyses were used to assess the pathogenicity of identified variants. A literature review of known EYA4 variants was performed, analysing variant frequency, distribution characteristics across different populations, and genotype-phenotype correlations. RESULTS: We identified a novel EYA4 variant, c.1745_1748del (p.Glu582ValfsTer6), in a Chinese family with ADNSHL, and co-segregation with the family's phenotype was confirmed. The audiometry showed mid-to-high frequency downsloping hearing loss. To date, 52 pathogenic variants of EYA4 have been reported, with majority identified in Asian populations. Most observed are the missense and frameshift variants. CONCLUSIONS: A novel variant of EYA4 was identified in a Chinese family with postlingual hearing loss, contributing to the expanding spectrum of EYA4 variants. The audiological features of EYA4 variants are highly heterogeneous and often challenging to detect early in clinical settings. Our findings highlight the significance of genetic testing in patients presenting with postlingual hearing loss.

Humans↗

PubMed2024

Prenatal diagnosis and molecular cytogenetic analysis of pure chromosome 10p15.3 microdeletion using chromosomal microarray analysis.

BACKGROUND: The literature contains exceedingly limited reports on chromosome 10p15.3 microdeletions. In the present study, two cases of fetuses with pure terminal 10p15.3 microdeletion syndrome in a Chinese population were examined, with the objective of enhancing understanding of the genotype-phenotype correlation associated with 10p15.3 microdeletions. METHODS: Two fetuses with chromosome 10p15.3 microdeletion were identified from a cohort of 5,258 cases undergoing amniocentesis. Karyotyping and chromosomal microarray analysis (CMA) was conducted to assess chromosomal abnormalities and detect copy number variations (CNVs) within the families, respectively. RESULTS: In Family 1, the fetus exhibited a 556.2-Kb deletion in the 10p15.3 region, encompassing OMIM genes such as DIP2C and ZMYND11, and presented with increased nuchal translucency on prenatal ultrasound examination. Parental CMA analysis revealed that the 10p15.3 microdeletion was inherited from the father, who displayed mild language impairment. In Family 2, a comparable 10p15.3 microdeletion was identified in a fetus presenting with asymmetric butterfly vertebrae at T10 and T12, along with mild scoliosis of the spine. Family 1 elected to terminate the pregnancy, while Family 2 chose to continue. At a follow-up conducted at one year and eight months, the child demonstrated delays in both speech and motor development. CONCLUSION: The present study is the first to report two cases of pure terminal chromosome 10p15.3 microdeletion syndrome in fetuses, offering valuable insights for the prenatal diagnosis of 10p15.3 microdeletion syndrome. Further, it is the first to describe mild clinical features, specifically limited to language impairment, in a patient with 10p15.3 microdeletion syndrome.

Female↗

PubMed2025

Identification of intragenic variants in pediatric patients with intellectual disability in Peru.

BACKGROUND: Intellectual disability in Latin America can reach a frequency of 12% of the population, these may include nutritional deficiencies, exposure to toxic or infectious agents, and the lack of universal neonatal screening programs. In 90% of patients with intellectual disability, the etiology can be attributed to variants in the genome. OBJECTIVE: to determine intragenic variants in patients with intellectual disability between 5 and 18 years old at Instituto Nacional de Salud del Niño. METHODS: It is a descriptive cross-sectional study with convenience sampling. A total of 124 children diagnosed with intellectual disability were selected based on psychological test results and availability for whole exome sequencing. In addition, a chromosomal analysis of 6.55 M was performed on ten patients with a negative result in sequencing. Relative and absolute frequencies and measures of central tendency and dispersion were determined according to their nature. In addition, multiple linear regression and Poisson regression were used to determine the association between some clinical characteristics and the probability of occurrence in patients with positive results. RESULTS: The median age of the patients was 6.3 (IQR = 5.95), males accounted for 57.3%, and 91.9% of the cases had mild intellectual disability. Exome sequencing determined the etiology in 30.6% of patients with intellectual disability, of which 52.6% were autosomal dominant inheritance. The most frequent genes found were MECP2, STXBP1 and LAMA2. A broad genotype-phenotype correlation was identified, highlighting the genetic heterogeneity of intellectual disability in this population. The presence of dermatologic lesions, dystonia, peripheral neurological disorders, and fourth finger flexion limitation were observed more frequently in patients with intellectual disability with "positive results". CONCLUSIONS: This study shows that one-third of patients with intellectual disability exhibit intragenic variants, highlighting the importance of genetic analysis for accurate diagnosis. The identification of genes such as MECP2, STXBP1, and LAMA2 underscores the genetic heterogeneity of intellectual disability in the studied population. These findings emphasize the need for genetic testing in clinical management and the implementation of early detection programs in Peru.

Humans↗

PubMed2025

Exploring the c.406 C > T variant in TNNI3 gene: pathogenic insights into restrictive cardiomyopathy.

BACKGROUND: Restrictive cardiomyopathy (RCM) is a rare cardiac disorder characterized by diastolic dysfunction and myocardial stiffness, frequently associated with genetic variants. We aimed to explore the genetic basis of RCM in a diagnosed patient through comprehensive genetic analysis. METHODS: Whole exome sequencing (WES) was conducted on the proband, followed by Sanger sequencing for variant confirmation and familial segregation analysis. In silico tools and structural protein modeling were employed to assess the functional impact of the identified variant. RESULTS: The c.406 C > T variant, classified as likely pathogenic, results in a truncated TNNI3 protein. Bioinformatics analysis highlighted significant structural disruptions, likely impairing sarcomere function. The patient presented with growth retardation, progressive dyspnea, and echocardiographic findings consistent with RCM. Both parents were heterozygous carriers, supporting an autosomal recessive inheritance pattern. The homozygosity of the novel variant identified in this study is a critical factor in the genotype-phenotype correlation observed in this case. CONCLUSION: This study identified the novel c.406 C > T variant in TNNI3 as a potential pathogenic driver of RCM, emphasizing the critical role of genetic evaluations in early diagnosis and management of inherited cardiomyopathies. Further studies are warranted to explore therapeutic interventions targeting TNNI3-related pathologies.

Humans↗

PubMed2026

Genomic determinants of fluoroquinolone resistance in Escherichia coli in Nigeria: dominance of QRDR mutations and limited contribution of PMQR in a cross-sectional study.

BACKGROUND: Fluoroquinolone-resistant Escherichia coli is a major global clinical threat, particularly in low- and middle-income countries like Nigeria. However, the full genomic landscape, including the relative contributions of chromosomal mutations, plasmid-mediated resistance, and the role of high-risk clones, remains poorly characterized in this setting. This study aimed to define the genomic mechanisms, clonal distribution, and genotype-phenotype relationships of fluoroquinolone resistance in clinical E. coli isolates from Nigeria. METHODS: A cross-sectional study of 107 clinical E. coli isolates was conducted. Phenotypic susceptibility to ciprofloxacin and nalidixic acid was determined using VITEK 2 and broth microdilution. Whole-genome sequencing was performed, and analysis included detection of quinolone resistance determining region (QRDR) mutations (gyrA, parC, parE) and plasmid-mediated quinolone resistance (PMQR) genes, multilocus sequence typing (MLST), and phylogenetic analysis. Statistical associations were evaluated using chi-squared tests or Fisher's exact tests. RESULTS: Ciprofloxacin non-susceptibility was high at 86.0%. Resistance was primarily driven by a conserved chromosomal mutation profile; the combination of gyrA S83L, gyrA D87N, and parC S80I was present in 85 isolates and was associated with ciprofloxacin non-susceptibility in all affected isolates in this cohort. Isolates with only gyrA mutations were resistant to nalidixic acid but susceptible to ciprofloxacin, consistent with a stepwise resistance pathway. In this cohort, the triple QRDR signature (gyrA S83L + gyrA D87N/Y + parC S80I) was a perfect positive predictor of ciprofloxacin non-susceptibility (85/85; 100%). The ST131 lineage dominated, accounting for 21.5% of isolates and universally carrying the complete triple QRDR profile; notably, no ST131 isolate carried a PMQR determinant. Plasmid-mediated quinolone resistance (PMQR) genes were detected in 15.0% of isolates but were not independently associated with ciprofloxacin non-susceptibility in this cohort in the absence of concomitant QRDR mutations. Efflux pump genes were ubiquitous and non-predictive. Notably, six isolates, all from urine, were non-susceptible (R/I) despite lacking all known QRDR and PMQR determinants, pointing to uncharacterized mechanisms. In a multivariable logistic regression model that included ST131 status, PMQR carriage, and parE mutation status, ST131 was associated with ciprofloxacin non-susceptibility (adjusted OR 5.96, 95% CI 1.21-29.4, p = 0.028), whereas PMQR carriage was not (adjusted OR 0.94, 95% CI 0.18-4.85, p = 0.94). The triple QRDR signature was not included in this model because it perfectly predicted ciprofloxacin non-susceptibility in this cohort. Resistance patterns varied by clinical source, with the highest burden in bloodstream and wound infections. This stepwise hierarchy from first-step gyrA mutations to the classic triple QRDR profile is summarised in the graphical abstract, Fig. 1. CONCLUSIONS: Fluoroquinolone resistance in Nigerian clinical E. coli is predominantly driven by chromosomal QRDR mutations within successful clones like ST131. PMQR genes and efflux pumps appeared to play a supplementary role rather than being independent drivers of ciprofloxacin resistance in this cohort. These data support prioritising key QRDR mutations in genomic reporting and local stewardship decisions, while the QRDR-negative resistant urine isolates require further investigation.

Escherichia coli↗

PubMed2024

The multifaceted role of mitochondria in cardiac function: insights and approaches.

Cardiovascular disease (CVD) remains a global economic burden even in the 21st century with 85% of deaths resulting from heart attacks. Despite efforts in reducing the risk factors, and enhancing pharmacotherapeutic strategies, challenges persist in early identification of disease progression and functional recovery of damaged hearts. Targeting mitochondrial dysfunction, a key player in the pathogenesis of CVD has been less successful due to its role in other coexisting diseases. Additionally, it is the only organelle with an agathokakological function that is a remedy and a poison for the cell. In this review, we describe the origins of cardiac mitochondria and the role of heteroplasmy and mitochondrial subpopulations namely the interfibrillar, subsarcolemmal, perinuclear, and intranuclear mitochondria in maintaining cardiac function and in disease-associated remodeling. The cumulative evidence of mitochondrial retrograde communication with the nucleus is addressed, highlighting the need to study the genotype-phenotype relationships of specific organelle functions with CVD by using approaches like genome-wide association study (GWAS). Finally, we discuss the practicality of computational methods combined with single-cell sequencing technologies to address the challenges of genetic screening in the identification of heteroplasmy and contributory genes towards CVD.

Humans↗

PubMed2026

Phylogeographic epidemiology of Dabie bandavirus in East Asia: divergent transmission networks and genotype‑linked clinical severity.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS), caused by Dabie bandavirus (SFTSV), exhibits geographically decoupled incidence and fatality patterns across East Asia. We aimed to elucidate the distinct ecological drivers and phylogeographic dynamics underlying this inland-coastal epidemiological divergence. METHODS: Integrating 1820 high-quality global genomes of SFTSV with well-characterized clinical cohorts (936 patients) and nationwide surveillance data (27,457 cases) from China, we constructed a comprehensive analytical framework. Ecological modeling, Bayesian phylogeography, and genotype-phenotype association analyses were employed to trace the evolutionary trajectories and clinical implications of the virus. RESULTS: A pronounced "inland-high-incidence vs. coastal-high-fatality" pattern of SFTS was identified. The incidence of SFTS exhibited divergent sensitivities to meteorological factors; inland transmission was sensitive to thermal fluctuations, whereas coastal dynamics were constrained by a sunshine threshold (> 200 h/month). In contrast, spatial divergence in clinical severity correlated with the distribution of regional viral genetic structures. Inland regions mainly co-circulated genotypes A, C, and D, while coastal regions were dominated by genotype B. Zhejiang province was identified as a genetic hub with significantly higher recombination frequencies than inland regions (11.0% vs. 3.5%, P < 0.001). Bayesian phylogeographic inference indicated frequent lineage exchange of Zhejiang province in China with the Republic of Korea and Japan. Clinically, genotypes B and D were associated with elevated mortality in coastal and inland regions, respectively, suggesting that the severe coastal phenotype is shaped by its genotype B-dominated structure. Additionally, the RdRp-N828S mutation emerged as a robust molecular correlate of fatal outcomes, warranting further functional validation. CONCLUSIONS: Divergent meteorological factors and plausible maritime transmission networks may underlie the geographically decoupled epidemiology of SFTS. These findings highlight that risk assessment must extend beyond incidence alone and provide a phylogeographically informed framework for targeted surveillance and genotype-specific interventions in high-risk hotspots.

Humans↗

PubMed2025

A spectral framework to map QTLs affecting joint differential networks of gene co-expression.

Studying the mechanisms underlying the genotype-phenotype association is crucial in genetics. Gene expression studies have deepened our understanding of the genotype  →  expression  →  phenotype mechanisms. However, traditional expression quantitative trait loci (eQTL) methods often overlook the critical role of gene co-expression networks in translating genotype into phenotype. This gap highlights the need for more powerful statistical methods to analyze genotype  →  network  →  phenotype mechanism. Here, we develop a network-based method, called spectral network quantitative trait loci analysis (snQTL), to map quantitative trait loci affecting gene co-expression networks. Our approach tests the association between genotypes and joint differential networks of gene co-expression via a tensor-based spectral statistics, thereby overcoming the ubiquitous multiple testing challenges in existing methods. We demonstrate the effectiveness of snQTL in the analysis of three-spined stickleback (Gasterosteus aculeatus) data. Compared to conventional methods, our method snQTL uncovers chromosomal regions affecting gene co-expression networks, including one strong candidate gene that would have been missed by traditional eQTL analyses. Our framework suggests the limitation of current approaches and offers a powerful network-based tool for functional loci discoveries.

Quantitative Trait Loci↗

PubMed2026

IBAS: Interaction-bridged association studies discovering novel genes underlying complex traits.

Genetic contributions to complex traits are often mediated through coordinated gene-gene interaction networks, yet most existing association frameworks focus on marginal single-gene effects and overlook higher-order dependency structures. Direct modeling of interactions remains challenging due to combinatorial complexity and statistical instability. We introduce Interaction-Bridged Association Study (IBAS), a general framework that incorporates pathway-level interaction patterns into genotype-phenotype association analysis without explicitly enumerating interactions. IBAS leverages transcriptomic reference data to construct low-dimensional representations of pathway activity, which guide SNP-weighting and gene-level association testing within a kernel-based framework. In perturbation-based simulations, IBAS demonstrates improved stability and reproducibility compared to conventional TWAS and gene-based methods, while maintaining well-calibrated Type I error under phenotype permutation. Application to the WTCCC datasets identifies both known and novel genes across multiple complex diseases, including candidates with modest marginal effects missed by standard approaches. These findings are supported by replication in an independent cohort, and analyses across multiple reference tissues revealing both shared and tissue-specific signals. Overall, IBAS provides a statistically robust and computationally tractable framework for incorporating interaction effects into association mapping, extending beyond the single-gene paradigm and enabling more comprehensive characterization of complex trait. IBAS is available on GitHub at: https://github.com/QingrunZhangLab/IBAS.

Polymorphism, Single Nucleotide↗

PubMed2026

Familial short stature: genetic architecture, risk stratification, and precision management.

BACKGROUND: Familial short stature (FSS) has traditionally been considered a benign growth pattern characterized by short stature clustering within families and has often been regarded as a normal variant of growth. However, recent advances in genomic technologies have demonstrated that a subset of children presenting with an FSS phenotype harbor identifiable monogenic variants, particularly in genes involved in growth plate development and skeletal growth. These findings challenge the traditional phenotype-based understanding of FSS and support an etiology-oriented diagnostic framework. OBJECTIVE: To summarize current knowledge regarding the genetic architecture of FSS, review existing clinical risk stratification frameworks for genetic evaluation, and evaluate available evidence regarding treatment outcomes across different genetic etiologies. METHODS: A literature search was performed in PubMed, Embase, and Web of Science from inception to May 2026, using keywords including "familial short stature," "familial idiopathic short stature," "genetic testing," "ACAN," "SHOX," and "NPR2". Relevant original studies and review articles addressing genotype-phenotype correlations, diagnostic yield of genetic testing, or responses to recombinant human growth hormone (rhGH) therapy were considered. RESULTS: Emerging evidence indicates that monogenic variants can be identified in a subset of children with an FSS phenotype, especially among those with more severe short stature and autosomal dominant inheritance patterns. Variants affecting growth plate biology represent some of the most frequently reported genetic causes of FSS, with ACAN, SHOX, and NPR2 being the most frequently implicated genes. Existing clinical frameworks based on parental height patterns and inheritance characteristics may help stratify patients with FSS according to the likelihood of monogenic etiology and guide selection of individuals who may benefit from genetic testing. Available evidence suggests that rhGH therapy may improve growth outcomes in several monogenic forms of FSS, although treatment responses vary according to genetic etiology. CONCLUSIONS: FSS should be regarded as a heterogeneous clinical phenotype rather than a single diagnostic entity. Integration of existing clinical risk stratification approaches with molecular diagnosis may enable more precise identification of underlying genetic causes and facilitate individualized therapeutic decision-making. Future advances in FSS management will likely depend on precision medicine approaches linking phenotype, genotype, and treatment response.

Humans↗

PubMed2026

Stepwise Humanization of the Yeast TRAPP Core Enables Functional Analysis of TRAPP Variants.

The Transport Protein Particle (TRAPP) complex is a highly conserved multi-subunit tethering complex that plays a critical role in membrane trafficking. Mutations in TRAPP complex subunits have been implicated in a growing spectrum of rare genetic disorders, yet the molecular mechanisms underlying variant pathogenicity often remain unclear. Here, we developed a humanized yeast platform to enable systematic functional characterization of TRAPP complex variants of uncertain significance. Using a stepwise gene replacement strategy in Saccharomyces cerevisiae, we constructed a strain in which five yeast TRAPP core subunits were replaced with their human orthologues. The integration of human subunits was validated through quantitative RT-PCR and Western blotting. Growth assays revealed that partial humanization of the core complex recapitulates key functional aspects of TRAPP assembly and enables the functional investigation of variants of uncertain significance in vivo. Structural modeling and clash analysis provided insights into the impact of specific mutations on complex stability and subunit interactions. TRAPPC3 has not yet been definitively associated with human disease. Introduction of TRAPPC3 variants of uncertain clinical significance into the humanized strain resulted in pronounced growth defects and predicted structural clashes. This work demonstrates the power of humanized yeast as a model for elucidating potential genotype-phenotype relationships in TRAPPopathy disorders and provides a versatile platform to support variant interpretation, mechanistic studies, and potential therapeutic screening.

Saccharomyces cerevisiae↗

PubMed2026

Expanding the Genomic Spectrum of NHLRC2-Associated FINCA Disease: Integrated Bioinformatic Characterization of a Novel Deep Intronic Variant Predicted to Activate a Pseudoexon.

NHLRC2-associated FINCA disease is an ultra-rare autosomal recessive multisystem disorder caused by biallelic pathogenic variants in NHLRC2. Its mutational spectrum and genotype-phenotype correlations remain incompletely defined, and the contribution of non-coding variants is poorly understood. Here, we report a male infant with a severe FINCA-like phenotype, including early-onset hemolytic anemia, pulmonary involvement, neurodevelopmental impairment, growth failure, recurrent infections, and fatal progression at 8.5 months. Whole-genome sequencing identified a compound heterozygous NHLRC2 genotype comprising the previously reported pathogenic missense variant c.442G>T (p.Asp148Tyr) and a novel deep intronic variant, c.331+6863A>G. Segregation analysis confirmed inheritance from different parents. Integrated genomic and splicing analysis predicted that c.331+6863A>G creates a strong cryptic donor splice site and supports pseudoexon inclusion. Reconstruction of the predicted aberrant transcript indicated premature termination and potential susceptibility to nonsense-mediated mRNA decay. To our knowledge, this is the first reported deep intronic NHLRC2 variant predicted to activate pseudoexon inclusion. Although experimental validation was unavailable, convergent clinical, segregation, population, and computational evidence supports c.331+6863A>G as the most plausible second disease-associated allele. This case expands the genomic spectrum of NHLRC2-associated FINCA disease and highlights the diagnostic value of phenotype-driven whole-genome sequencing.

Humans↗