Search Results (1,236)

Basonuclin 2 (BNC2) is a highly conserved cysteine–histidine (C2H2)-type zinc-finger nuclear regulatory protein characterized by three pairs of zinc-finger domains, a putative nuclear localization signal, a serine-rich region, broad tissue distribution, and remarkable transcript diversity generated through alternative promoter usage, alternative splicing, and polyadenylation. Increasing evidence from human genetics, animal models, functional genomics, and transcriptomic studies indicates that BNC2 links nuclear regulatory mechanisms to tissue-specific developmental and disease phenotypes. In the nervous system, BNC2-positive neuronal populations and BNC2-derived circular RNAs have been implicated in energy-balance circuits and neuroinflammatory regulation. In the skeletal system, BNC2 contributes to osteochondral development, periosteal stem-cell activation, chromatin remodeling, fracture repair, and genetic susceptibility to adolescent idiopathic scoliosis. BNC2 variants have also been associated with congenital lower urinary tract obstruction, whereas its expression and regulatory landscape are closely related to germ-cell development, epithelial ovarian cancer susceptibility, pigmentation traits, fibrosis, and several tumor contexts. Mechanistically, BNC2-associated phenotypes appear to involve cysteine–histidine zinc-finger-mediated transcriptional regulation, non-coding enhancer activity, epigenetic alterations, RNA-processing-associated nuclear functions, and chromatin-remodeling-dependent control of cell proliferation, differentiation, and stromal activation. This review integrates current evidence on the molecular architecture and regulatory functions of BNC2, critically discusses its context-dependent roles across development and disease, and highlights unresolved questions regarding isoform-specific activity, cell-type-specific regulation, downstream target networks, and clinical translation. A clearer understanding of these mechanisms may support the future evaluation of BNC2 as a biomarker, genetic susceptibility locus, molecular stratification factor, and potential therapeutic regulatory node. Full article

Background: Pathogenic BRCA1 and BRCA2 mutations confer a homologous recombination deficiency that underlies PARP inhibitor sensitivity. While BRCA1 mutation carriers more frequently develop triple-negative breast cancer (TNBC) and BRCA2 carriers hormone receptor-positive (HR+) disease, whether the specific protein domain harboring a pathogenic somatic mutation differs systematically between breast cancer subtypes remains uncertain. Apparent domain enrichment in earlier unfiltered analyses may be confounded by missense variants of uncertain significance (VUSs), which lack clinical actionability. Methods: We assembled three independent breast cancer cohorts via cBioPortal: TCGA-BRCA (brca_tcga_pub2015), METABRIC (brca_metabric), and MSK-CHORD (msk_chord_2024). All somatic BRCA1/2 mutations were mapped to UniProt-annotated functional domains and to Rebbeck-defined breast/ovarian cancer cluster regions (BCCR/OCCR). Per ENIGMA/ACMG guidance, pathogenic mutations (nonsense, frameshift, and canonical splice site) were analyzed inferentially, while missense and in-frame variants—predominantly VUSs—were only reported descriptively. Fisher’s exact tests with Benjamini–Hochberg FDR correction were applied across domain × subtype contingencies. Cohort heterogeneity was assessed via Cochran’s Q and I² statistics; pooled effect estimates were computed using inverse-variance fixed-effects meta-analysis. Results: A total of 394 somatic BRCA1/2 mutations were identified across the three cohorts (BRCA1 n = 166; BRCA2 n = 228), of which 147 (37.3%) met pathogenic criteria. Among 131 pathogenic mutations in HR+/HER2− or TNBC subtypes, 84 (64.1%) occurred in HR+/HER2− disease and 47 (35.9%) in TNBC. Domain-level distributions did not differ significantly between subtypes for any BRCA1 domain (BRCT: TNBC 20.0% vs. HR+ 18.8%, OR = 1.08, 95% CI 0.31–3.78, and FDR-adjusted p = 1.00) or BRCA2 domain (DBD: TNBC 17.6% vs. HR+ 30.8%, OR = 0.48, and FDR-adjusted p = 1.00). Cluster-region analyses (nine Rebbeck BCCR/OCCRs) similarly showed no significant enrichment. Post hoc power analysis indicated that the study could only reliably detect large effects (OR ≥ ~3.0 for the principal BRCT contrast), and formal equivalence testing (TOST) demonstrated equivalence within a prespecified ±20% margin for BRCA1 BRCT (TOST p = 0.031). Heterogeneity across cohorts was minimal (Cochran’s Q = 0.62, I² = 0.0%). Descriptive analyses of VUSs suggested the apparent enrichment of BRCA1 BRCT-localized missense variants in TNBC (31.8% vs. 17.9% in HR+), but this signal did not extend to pathogenic mutations. Conclusions: Within the statistical power available, our three-cohort analysis shows no evidence of large subtype-specific enrichment of pathogenic BRCA1/2 somatic mutations across protein domains or cluster regions; small to moderate effects cannot be excluded. Notably, the majority (64%) of pathogenic mutations occurred in HR+/HER2− disease, underscoring that BRCA1/2 testing should not be deprioritized in non-TNBC subtypes. The apparent BRCT enrichment observed in earlier unfiltered analyses appears to be driven by VUSs rather than pathogenic variants, highlighting the methodological necessity of pathogenicity filtering for clinically actionable inference. These findings provide cohort-scale supportive evidence for emerging clinical guidelines that recommend broader BRCA1/2 testing across breast cancer subtypes. Full article

Testicular germ cell tumor (TGCT) is a common tumor type in young men. Family history of TGCT and its presence in twins support the involvement of inherited genetic factors. Germline exome sequencing was performed on monozygotic twins with TGCT and their parents. The twins presented compound heterozygous variants in PDE11A (rs776984134 and rs17400325) inherited from each parent. The rs776984134 variant disrupts the canonical splice acceptor site, leading to aberrant splicing and a frameshift predicted to affect protein structure. The rs17400325 missense variant, located in the catalytic domain, reduces hydrogen bonding capacity and may impair protein stability. Both variants map to a genomic region overlapping the antisense lncRNA PDE11A-AS1. In silico transcript-level analysis predicted multiple energetically favorable RNA–RNA interactions between PDE11A and PDE11A-AS1 transcripts, with rs17400325 located within predicted hybridization regions of several isoforms. These results suggest a potential impact on PDE11A–PDE11A-AS1 pairing and post-transcriptional regulation. Additional variants in MSH6 and CTU2 were also identified and may act as potential modifiers of disease susceptibility, consistent with a multigenic contribution to TGCT risk. These findings support a contributory role for the PDE11A locus in TGCT predisposition and underscore the biological relevance of overlapping sense–antisense genomic regions in hereditary cancer studies. Full article

Background/Objectives: Arthrochalasia Ehlers–Danlos syndrome (aEDS) is a rare connective tissue disorder characterized by severe joint hypermobility, congenital hip dislocation, skin hyperextensibility, and muscle hypotonia. It is typically caused by heterozygous splice-site variants in COL1A1 or COL1A2, leading to exon 6 skipping. Autosomal recessive forms are extremely rare and have been reported predominantly in families from Saudi Arabia carrying the homozygous COL1A1 missense variant c.2050G>A, p.(Glu684Lys), with clinical presentations ranging from severe to mild. Methods: Clinical and molecular genetic evaluation of the patient was performed. Whole-exome sequencing was carried out, followed by confirmatory Sanger sequencing in the proband and both parents. Results: A 10-month-old boy presented with severe congenital hypotonia, bilateral hip dislocation, generalized joint hypermobility, skin hyperextensibility and craniofacial dysmorphism. A homozygous likely pathogenic variant NM_000088.4:c.2050G>A, p.(Glu684Lys) was identified in exon 31 of COL1A1; both healthy parents were confirmed to be heterozygous carriers of this variant. To our knowledge this is the first reported case in the Russian population and one of the few cases described worldwide of an autosomal recessive arthrochalasia-like EDS phenotype. Conclusions: This case further refines the phenotypic characterization associated with the recurrent homozygous COL1A1 p.(Glu684Lys) variant, demonstrating an arthrochalasia-like EDS phenotype of intermediate severity between the severe neonatal form with respiratory distress and recurrent fractures and the classical EDS. It further highlights the importance of considering collagenopathies in the differential diagnosis of congenital hypotonia, particularly in cases initially suggestive of neuromuscular disorders. Full article

Holotrichia parallela is a globally distributed soil-dwelling pest that poses a major threat to peanut cultivation in China. Neuropeptides, as critical signaling molecules, regulate multiple physiological and behavioral processes in insects and represent highly promising targets for pest management. To date, the functional characteristics of neuropeptides in H. parallela remain unreported. In this study, we isolated and cloned one NPF and one NPFR gene, respectively. Bioinformatics analysis revealed that alternative splicing of the NPF gene produces two transcript variants, NPFa (255 bp) and NPFb (369 bp). The NPFR gene spans a length of 1188 bp, encoding 395 amino acids that contain seven α-helical transmembrane domains, indicating that it belongs to the family A G protein-coupled receptor (GPCR) family. Spatiotemporal expression profiles demonstrated that NPF was most abundant in the adult brain, whereas NPFR was highly enriched in the brain and antennae. NPF expression peaked in second-to-third-instar larvae, while NPFR was highly expressed in eggs. Starvation stress significantly upregulated the expression of both genes. RNA interference (RNAi)-mediated silencing of NPF and NPFR significantly reduced food intake, female fecundity, and glycogen content in adults. These findings enhance our understanding of insect neuropeptides signaling networks and support the development of behavior-based pest control strategies. Full article

Primary sclerosing cholangitis (PSC) and ulcerative colitis (UC) exhibit a striking clinical comorbidity, with 60–80% of PSC patients concurrently harboring UC, yet the shared immunogenetic mechanisms remain poorly understood. Here, we constructed a multi-omics integrative framework to systematically dissect the cellular and molecular basis of this comorbidity. GWAS meta-analyses were performed for each disease, followed by tissue-level enrichment assessment using QTLEnrich, MAGMA, and gsMap spatial mapping. Single-cell transcriptomic atlases were constructed, and cell-type prioritization was conducted using four complementary methods. Core genes were identified through cross-validation of five algorithms, with subsequent genomic fine-mapping via FUMA and GCTA-COJO. Tissue-level analyses consistently identified the intestine and immune-related tissues as commonly affected. Multi-dimensional evidence integration prioritized natural killer (NK) cells as the core effector cell type for both diseases, supported principally by CELLECT (Cell-type Expression-specific Integration for Complex Traits) heritability enrichment and single-cell differential analysis. Convergence of five gene-level algorithms pinpointed STAT3 as the sole high-confidence comorbidity gene, broadly expressed across immune cell populations and exhibiting tissue-differential alternative splicing. Colocalization identified a high-risk variant (rs3736161) within the STAT3 locus, with conditional analysis revealing 35 additional independent signals. These findings identify the NK cell–STAT3 axis as a central immunogenetic hub connecting PSC and UC, offering potential therapeutic targets for comorbidity management. Full article

Chitin synthase (CHS) catalyzes the final polymerization step in chitin biosynthesis and is therefore central to cuticle formation in arthropods. In this study, a chitin synthase gene from the swimming crab Portunus trituberculatus (PtCHS) was identified and functionally characterized in relation to epidermal formation and molting. The open reading frame of PtCHS was 4731 bp and encoded a predicted protein of 1576 amino acids belonging to glycosyltransferase family 2. Domain prediction revealed multiple transmembrane helices, a conserved chitin-synthase catalytic region, a coiled-coil region, and the diagnostic EDR, QRRRW, and SWGTRE motifs. Phylogenetic analysis assigned PtCHS to the class A/CHS1 chitin synthase lineage, and two alternative splice variants, designated PtCHS1a and PtCHS1b were detected. PtCHS transcripts were broadly distributed across examined tissues, with comparatively high abundance in the Y-organ, midgut, ovary, and epidermis. During the molting cycle, epidermal PtCHS expression increased during premolt, reached its highest level in postmolt stages, and declined during intermolt. During embryonic development, PtCHS expression remained relatively stable until late embryogenesis and then increased sharply before hatching. RNA interference-mediated knockdown of PtCHS reduced the expression of key chitin-biosynthesis genes, decreased epidermal chitin content, prolonged the molting interval, and was associated with molting failure and increased mortality. Conversely, unilateral eyestalk ablation induced PtCHS and molting-related genes, increased epidermal chitin content, shortened the molting interval, and promoted histological features consistent with enhanced extracellular matrix deposition and epidermal biosynthesis. These findings indicate that PtCHS is indispensable for epidermal chitin deposition and successful molting in P. trituberculatus, and provide a molecular basis for understanding molting regulation in economically important portunid crabs. Full article

Background/Objectives: Recessive titinopathies caused by biallelic TTN truncating variants (TTNtvs) present a clinically heterogeneous spectrum from fetal demise to late-onset slowly progressive distal muscular dystrophy. Prognostic counseling is challenging due to the vast size of the TTN gene, complex splicing patterns, and differential expression throughout developmental stages and tissues. This paper aims to delineate the regional genotype patterns and clinical characteristics of recessive titinopathies described from the prenatal period onwards to inform genotype–phenotype associations and genetic counseling. Methods: We analyzed clinical and genetic data from a prenatal-onset cohort with biallelic TTNtvs from both previously reported cases and novel cases from our center. To characterize the regional distribution of biallelic variants within this specific cohort, a two-dimensional scatter plot was utilized to map variants onto 10 biological regions (R1–R10) and 55 analytical units (U1–U55). We also performed Fisher’s exact tests on the subset of 50 cases with confirmed survival records to evaluate statistically significant associations between biallelic regional or percent spliced-in (PSI) thresholds combinations and severe clinical endpoints (intrauterine demise or death before 5 years). Results: A total of 96 prenatal cases from 76 unrelated families were analyzed. Decreased fetal movement was the most commonly reported symptom, observed in 81.3% (78/96) of cases, which was followed by arthrogryposis in 45.8% (44/96) and amniotic fluid volume abnormalities in 35.4% (34/96). Additionally, of the 95 cases with known pregnancy outcomes, 25.3% (24/95) resulted in termination and 11.6% (11/95) resulted in intrauterine demise (IUD), while 63.2% (60/95) reached birth with over 16.7% (10/60) being preterm. Among 60 live-born infants, severe postnatal morbidity was high: 45.0% (27/60) experienced respiratory failure, and 33.3% (20/60) died before the age of five. In this cohort, 84.4% (81/96) of cases possessed at least one TTNtv in either the metatranscript-only or A-band regions. The most common biallelic changes involved TTNtvs in both the A-band and metatranscript-only regions, accounting for 35.4% (34/96) of cases, followed by metatranscript-only combined with I-band variants at 16.7% (16/96), regardless of the PSI score of exons. Overall, 83.3% (80/96) had ≥1 variant on low-PSI (<50%) exons, and 19.8% (19/96) had both alleles on these low-PSI exons. In the 50 patients with confirmed survival records, biallelic changes (excluding splice-site variants) affecting both high-PSI (>90%) exons were significantly associated with severe outcomes (intrauterine demise or death before 5 years; exact p = 0.015), whereas the metatranscript-only plus I-band combination conferred a significantly lower risk of lethality before 5 years of age (exact p = 0.001). Conclusions: Our findings add to the accumulating evidence that TTNtvs on low PSl exons or metatranscript-only regions are frequently observed among reported prenatal-onset recessive titinopathy. Health surveillance for heterozygous carriers among family members is warranted due to the substantial risk for adult-onset dilated cardiomyopathy and peripartum cardiomyopathy. Full article

Background: Alport syndrome is a hereditary disorder caused by defects in the type IV collagen network. Although exon variants are primarily associated with Alport syndrome, the clinical significance of intronic variants remains incompletely characterized. The aim of this study was to characterize the clinical and molecular features of a familial case of Alport syndrome associated with the intronic variant c.1588-2A>G and to assess its impact using in silico tools. Case description: Two affected siblings presented with hematuria, proteinuria, and renal biopsy demonstrated focal global and segmental glomerulosclerosis, findings consistent with Alport syndrome. Whole-exome sequencing was subsequently performed in patients. The variant (NM_033380.2, c.1588-2A>G) in intron 23 of the COL4A5 gene was identified in both probands. SpliceAI analysis demonstrated a complete loss of the canonical acceptor site and a high probability of cryptic site activation. Conclusion: The evidence suggests a likely pathogenic role of the COL4A5 c.1588-2A>G variant in Alport syndrome. Full article

Primary ciliary dyskinesia (PCD) is a rare genetic disorder mainly characterized by impaired mucociliary clearance and chronic respiratory symptoms. From a consanguineous family, a male patient, although with respiratory complaints since birth, was diagnosed with PCD only in adulthood. Whole-exome sequencing disclosed a novel homozygous intronic single-nucleotide deletion, NM_001369.3(DNAH5):c.13723+4del, initially classified as of uncertain clinical significance. Digital highspeed videomicroscopy (HSVM) evidenced a null ciliary beating frequency; transmission electron microscopy showed absence of outer dynein arms (class-1); and immunofluorescence (IF) demonstrated markedly absent DNAH5 protein level in the apical cilia region with delocalization to the transition and basal-body regions. Bioinformatic analysis predicted altered splicing at the donor splice site of exon 78, whereas mRNA sequencing revealed two splicing defects: the mainly expressed transcript corresponding to exon 78 skipping and a minor transcript originated from a cryptic splice site in exon 78. The patient was infertile and showed severe oligoteratozoospermia. Sperm IF analysis revealed absence of DNAH5 from the flagellum with accumulation at the neck region. The family study confirmed homozygosity. The present results support a pathogenic role for the c.13723+4del variant and underscore the importance of integrating clinical, ultrastructural, DNA, mRNA and protein analyses to clarify and contribute to PCD diagnosis. Full article

Background/Objectives: Genomic testing has transformed rare-disease diagnostics, yet a substantial proportion of individuals remain without a molecular diagnosis even after short-read exome sequencing (SR-ES) or short-read genome sequencing (SR-GS) and repeated conventional analysis. Methods: To address this persistent gap, we evaluated a coordinated multimodal reanalysis framework for deeply investigated families with suspected monogenic disease. Six families (20 individuals; 8 affected individuals) that had remained unsolved after prior comprehensive testing were reviewed prospectively in weekly interdisciplinary case conferences over one year. Available data included SR-ES, SR-GS, long-read genome sequencing (LR-GS), RNA-seq, optical genome mapping, mobile-element analysis, and mitochondrial genome analysis. The goal was not to test a single modality in isolation, but to assess whether systematic escalation across complementary assays plus continued reinterpretation could improve case resolution. Results: Three families (50%) achieved a reportable molecular diagnosis, two (33%) yielded strong candidate findings requiring additional evidence, and one (17%) remained without a definitive new molecular diagnosis, although reinterpretation of a previously identified NOTCH3 variant provided a possible partial explanation. Resolved cases included compound-heterozygous variants in KLHL40, a 119 kb multi-exon deletion in TTN, and a recurrent insertion in RNU4-2. Candidate findings included biallelic NARS2 variants and a 1.3 kb intragenic deletion involving ZEB2. Functional transcriptomic analyses supported the KLHL40 and TTN diagnoses but did not demonstrate a splicing consequence for the candidate NARS2 intronic variant in cardiac tissue. Conclusions: This small pilot cohort is not intended to estimate general diagnostic yield, but it demonstrates that a coordinated multimodal framework can reveal different sources of added value, including structural variant discovery, orthogonal functional support, and reinterpretation of existing short-read data as knowledge evolves. These findings underscore that archived short-read exome and genome data can retain substantial diagnostic value years after initial testing, particularly when reanalyzed with updated pipelines, expanded disease gene knowledge, and orthogonal multimodal evidence. Adoption of iterative, team-based multimodal strategies may help resolve the most complex unsolved rare-disease cases. Full article

Physical inactivity contributes to type 2 diabetes (T2D), but the molecular links between exercise and metabolic improvement remain incompletely understood. We meta-analyzed genome-wide association studies of vigorous physical activity and T2D (combined n ≈ 1.95 million) and integrated eQTL/sQTL maps with single-cell and spatial transcriptomic datasets to connect genetic risk with tissues, cell types, and regulatory programs. Tissue and cell-type enrichment, colocalization, and network analyses were performed. Computational findings were further examined in male 10-week-old C57BL/6J mice with high-fat diet-induced diabetes. After 1 week of acclimatization, mice were randomly assigned to normal chow, high-fat diet, or high-fat diet plus exercise groups (n = 6 per group; high-fat diet with 60% of total energy from fat). The exercise intervention consisted of treadmill running (10 m/min for 50 min per day, 5 days per week, total 16 weeks), followed by metabolic phenotyping, skeletal muscle histology, bulk RNA sequencing, alternative splicing analysis, and RT-qPCR of Mau2 isoforms. Exercise- and T2D-associated variants showed joint enrichment in skeletal muscle and adipose eQTL/sQTL signals. Integrated single-cell analyses prioritized fibro-adipogenic progenitors and endothelial cells, and identified an extracellular matrix- and collagen-related module in fibro-adipogenic progenitors associated with both exercise and T2D. Mau2 emerged as a shared candidate gene with tissue-specific splicing signals. In diabetic mice, exercise improved glucose homeostasis and muscle fiber structure, and reduced Mau2 intron retention in skeletal muscle without changing total Mau2 expression. These findings support a multiscale framework linking exercise-responsive regulation to T2D-related tissue remodeling and splicing plasticity. Full article

Background/Objectives: Autism spectrum disorder (ASD) is a neurodevelopmental disease with both clinical and genetic heterogeneity. Several loss-of-function variants in the chromodomain helicase DNA-binding protein 8 (CHD8) gene have been identified in individuals with ASD and/or developmental delay/intellectual disability. These are associated with specific clinical manifestations, including overgrowth, macrocephaly, sleep disturbance, and gastrointestinal problems. Methods: We performed clinical exome sequencing in a female patient with ASD and macrocephaly. RNA analysis from peripheral blood was carried out to investigate the functional effect of the identified variants. Results: We identified a novel maternally inherited CHD8 variant (c.5390+2T>C). Transcript analysis demonstrated that this variant disrupts the canonical splice donor in intron 30, causing splicing anomalies in the CHD7-binding domain of the CHD8 protein, resulting in a truncated inactive protein. Conclusions: In conclusion, this study identified a novel splice-site variant in the CHD8 gene with experimentally confirmed pathogenic effects on RNA splicing, expanding the mutational spectrum of CHD8-related neurodevelopmental disorders. The considerable intrafamilial phenotypic variability associated with CHD8 haploinsufficiency supports the presence of reduced penetrance and highlights the influence of modifying factors on the clinical expression of CHD8-related disorders. Full article

Upshaw–Schulman syndrome (USS) is a rare inherited autosomal recessive thrombotic microangiopathy affecting less than 1/1,000,000 individuals. It is a congenital form of thrombotic thrombocytopenic purpura (TTP) caused by ADAMTS13 protease deficiency because of mutations in the ADAMTS13 gene. USS is characterized by the formation of platelet thrombi in the microcirculation, accompanied by hemolytic anemia, thrombocytopenia, and clinical and laboratory signs of renal and neurological failure. The aim of this study was to describe the ADAMTS13 gene mutation spectrum in the Russian population. We analyzed the ADAMTS13 gene in 45 unrelated patients with TTP of unknown origin. DNA was extracted from blood cells using the phenol-chlorophorm method, and all exons of the gene were investigated using Sanger sequencing. In 15 out of 45 patients, we identified 20 different variants associated with USS, including two frameshift, two variants affecting the splice site, one nonsense and fifteen missense mutations. Eight out of those mutations were previously undescribed. Tree variants were revealed more than once: p.Arg1060Trp (7 patients), p.Glu1326ArgfsTer6 (7 patients) and p.Cys1067SerfsTer30 (3 patients). Variants (p.Arg1060Trp) and p.Glu1326ArgfsTer6 prevailed in the global population; however, p.Cys1067SerfsTer30 was not previously described in the European population. Our results expand the existing knowledge of the molecular basis of USS and may contribute to improved genetic diagnostics in Russia. Full article

This study is a narrative review of natural killer (NK) cells in Behcet disease (BD). BD is an inflammatory disorder with manifestations in mucosal tissues. Unlike autoimmune diseases that generate autoantibodies, BD is believed to be an autoinflammatory disease triggered by innate immune cells rather than adaptive cells. Hyperactivation of neutrophils causes vasculitis and thrombosis, and they migrate into cutaneous and ocular lesions. Dominance of M1 macrophages promotes the differentiation of Th1 cells. Moreover, the cross-reaction of bacterial heat shock proteins induces production of cytokines such as IL-4 and IFN-γ in γδT cells, which alters the balance between Th1 and Th2 phenotypes. Nevertheless, NK cells play more critical roles in BD pathogenesis than other innate immune cells because not only is their activity precisely controlled by the interaction between ligands and receptors, but NK1 shift also elicits Th1 dominance. The genetic factors associated with BD are HLA-B51 and major histocompatibility complex class I-related chain A (MICA), which stimulate NK receptors as ligands. Improperly processed peptides dysregulate their interaction with NK receptors, triggering the inflammatory response. NK1 and NK2 subsets represent cytokine production in relapse and remission periods; however, the cytotoxicity of NK cells in relapse is lower than that in remission periods. It still remains unclear how NK cells are activated recurrently and expand cytokine production. This review highlights the regulation of gene expression encoding NK receptors, tissue-resident NK cells, and adaptive NK cells to discuss their potential for relapse. Splicing variants and readthrough genes encoding NK receptors easily alter cytokine production. Moreover, tissue-resident NK cells in mucosal tissues and adaptive NK cells that memorize the virus infection have the potential to trigger hyperactivation in relapse. Full article