Search Results (180)

Diurnal birds of prey (Falconiformes and Accipitriformes) often display karyotypes that diverge markedly from the putative ancestral avian condition (2n = 80), with reduced diploid numbers and fewer microchromosome pairs driven by extensive chromosomal rearrangements. The harpy eagle (Harpia harpyja) was the first raptor analyzed by chromosome painting, revealing a karyotype (2n = 58) shaped by both microchromosome fusions and macrochromosome fissions followed by secondary fusions. However, these earlier analyses were limited in probe coverage. Here, we present a comprehensive chromosomal map of H. harpyja using multidirectional chromosome painting combined with chromosome-level genome assembly data. We integrated cross-species probes from Gallus gallus and Leucopternis albicollis with high-resolution genomic data to refine syntenic relationships and identify fission–fusion hotspots. G. gallus probes confirmed most previously described and genomically inferred associations but revealed novel features, including a new GGA1/GGA3 association and an increased number of GGA1-derived segments (five to six). Genomic data did not support previously suggested fusions involving GGA20–HHA1 or GGA12–Z. Dual-probe FISH further uncovered lineage-specific rearrangements, indicating rapid chromosomal evolution within Accipitriformes. This integrative approach clarifies harpy eagle genome organization and highlights dynamic evolutionary restructuring in raptor chromosomes. Full article

Background/Objectives: Flea beetles (Coleoptera, Chrysomelidae: Alticinae) show extensive karyotypic diversity, yet cytogenetic and genomic data remain scarce for many taxa. Species of the genus Podagrica are characterized by unusually high chromosome numbers compared with the modal condition in Alticinae, suggesting a history of chromosomal fissions. This study aimed to characterize the karyotype and repetitive DNA composition of Podagrica fuscicornis, with special emphasis on the satellitome and its contribution to chromosome organization. Methods: Male specimens of P. fuscicornis collected in southern Spain were analyzed using conventional cytogenetic techniques, including Giemsa staining, DAPI staining, and C-banding. Fluorescence in situ hybridization was employed to map nucleolar organizer regions (NORs), telomeric repeats, and major satellite DNA (satDNA) families. The satellitome was characterized using Illumina short-read sequencing and analyzed with the RepeatExplorer2/TAREAN pipeline to identify satDNA families and estimate their genomic abundance and divergence. Results: The male karyotype of P. fuscicornis was 2n = 40 (38 + XY), with an Xy_p sex chromosome system. Constitutive heterochromatin was mainly pericentromeric, and the Y chromosome was largely heterochromatic. NORs were located on a single autosomal pair, and the ancestral insect telomeric motif (TTAGG)_n was detected at chromosome ends. The satellitome comprised at least 70 different satDNA families, representing 9.51% of the genome, some of them related to transposable elements. Ten of these 70 satDNAs are shared in other Alticinae species. The most abundant families were primarily localized in pericentromeric regions and showed differential distribution between autosomes and sex chromosomes. Conclusions: These results indicate that extensive chromosomal fissions and high satDNA dynamics could drive the high chromosome number and heterogeneous genome organization in P. fuscicornis, highlighting the role of repetitive DNA in karyotype evolution within Chrysomelidae. Full article

Background/Objectives: Variation in repeatome composition is a major determinant of genome architecture and an important substrate for evolutionary change in plants. Despite the availability of genomic sequence data, repeatome-wide assessments have not been performed for Epidendrum, the largest Neotropical genus of Orchidaceae. Here, we assessed repeatome profiles across 34 Epidendrum species using publicly available genomic datasets. Methods:Epidendrum repeatomes were characterized with the RepeatExplorer2 pipeline, and patterns of repeat composition were evaluated for phylogenetic structure using a species phylogeny. Results: Repeat composition showed no clear phylogenetic structure, with closely related species often displaying divergent satDNA and TE profiles. satDNA content varied widely among species (15.5–69% of the repeatome fraction). A total of 208 satDNA families were detected, which were used to build a custom database for comparative analyses. We detected 73 satDNA clusters shared among species, whereas only three were species-specific. Regarding TEs, Class I elements were the most abundant repeats, dominated by Ty3-Gypsy LTR retrotransposons. Only two Class II TIR superfamilies were detected (EnSpm/CACTA and hAT). Conclusions: This study provides the first comprehensive characterization of the Epidendrum repeatome and establishes a resource for future work on cytogenomic diversity within this megagenus. The heterogeneous distribution of repeats among closely related species is consistent with lineage-specific amplification and loss, highlighting rapid repeatome turnover in Epidendrum. Potential drivers, as hybridization and ecological differentiation, should be tested explicitly in future analyses integrating broader genome size sampling and trait data. Full article

22q11.2 deletion syndrome (22q11.2DS) is the most common recurrent microdeletion in humans and a prototypical high-risk neurogenetic copy number variant (CNV) associated with a broad spectrum of neurodevelopmental and psychiatric disorders, including intellectual disability (ID), autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), anxiety, and psychotic symptoms. This hemizygous deletion encompasses multiple genes involved in brain development and neural circuit function, contributing to marked phenotypic variability and multisystem involvement. In pediatric populations, deficits in adaptive functioning are frequently reported and may occur independently of global intellectual impairment, reflecting broader behavioral vulnerabilities within this genetic risk architecture. Background/Objectives: This study aimed to characterize the sociodemographic, clinical, and intellectual profiles of children and adolescents with 22q11.2DS and to examine adaptive functioning and its associations with behavioral difficulties. Methods: Thirty-four patients aged 1–17 years with a confirmed molecular diagnosis of 22q11.2DS were assessed. Standardized instruments were used to evaluate cognitive performance, adaptive functioning, and behavioral outcomes. Results: Intellectual disability was highly prevalent, with most participants showing combined cognitive and adaptive impairments. Adaptive functioning was compromised across domains, with relatively higher socialization scores compared to other areas, such as daily living skills. Multivariate analyses indicated associations between sociodemographic factors and behavioral difficulties, as well as between social problems and lower global adaptive functioning. Conclusions: Together, these findings contribute to the characterization of the adaptive and behavioral phenotype associated with a high-risk neurogenetic CNV and highlight the relevance of adaptive functioning as a key outcome for early evaluation and intervention in pediatric 22q11.2DS. Full article

Background: Optical genome mapping (OGM) detects genome-wide structural variants (SVs), including balanced rearrangements and complex copy-number alterations beyond standard-of-care cytogenomic assays. In chronic lymphocytic leukemia (CLL), cytogenetic and genomic risk stratification is traditionally based on fluorescence in situ hybridization (FISH), karyotyping, targeted next-generation sequencing (NGS), and immunogenetic assessment of immunoglobulin heavy chain variable region (IGHV) somatic hypermutation status, each of which interrogates only a limited aspect of disease biology. Methods: We retrospectively evaluated fifty patients with CLL using OGM and integrated these findings with cytogenomics, targeted NGS, IGHV mutational status, and clinical time-to-first-treatment (TTFT) data. Structural variants were detected using OGM and pathogenic NGS variants were derived from a clinical heme malignancy panel. Clinical outcomes were extracted from the electronic medical record. Results: OGM identified reportable structural variants in 82% (41/50) of cases. The most frequent abnormality was del(13q), observed in 29/50 (58%) and comprising 73% (29/40) of all OGM-detected deletions with pathologic significance. Among these, 12/29 (42%) represented large RB1-spanning deletions, while 17/29 (58%) were focal deletions restricted to the miR15a/miR16-1 minimal region, mapping to the non-coding host gene DLEU2. Co-occurrence of adverse lesions, including deletion 11q/ATM, BIRC3 loss, trisomy 12, and deletion 17p/TP53, were recurrent and strongly associated with shorter TTFT. OGM also uncovered multiple cryptic rearrangements involving chromosomal loci that are not represented in the canonical CLL FISH probe panel, including IGL::CCND1, IGH::BCL2, IGH::BCL11A, IGH::BCL3, and multi-chromosomal copy-number complexity. IGHV data were available in 37/50 (74%) of patients; IGHV-unmutated status frequently co-segregated with OGM-defined high-risk profiles (del(11q), del(17p), trisomy 12 with secondary hits, and complex genomes whereas mutated IGHV predominated in OGM-negative or structurally simple del(13q) cases and aligned with indolent TTFT. Integration of OGM with NGS further improved genomic risk classification, particularly in cases with discordant or inconclusive routine testing. Conclusions: OGM provides a comprehensive, genome-wide view of structural variation in CLL, resolving deletion architecture, identifying cryptic translocations, and defining complex multi-hit genomic profiles that tracked closely with clinical behavior. Combining OGM and NGS analysis refined risk stratification beyond standard FISH panels and supports more precise, individualized management strategies in CLL. Prospective studies are warranted to evaluate the clinical utility of OGM-guided genomic profiling in contemporary treatment paradigms. Full article

MEDNIK syndrome (Mental Retardation, Enteropathy, Deafness, Neuropathy, Ichthyosis and Keratodermia) is a severe hyper-rare condition resulting from the biallelic variants in the AP1S1 gene, implicated in intracellular trafficking and copper homeostasis. Only 18 affected individuals (seven AP1S1 pathogenic variants overall) have been reported to date, with a high early lethality due to life-threatening congenital enteropathy. Seven patients have been empirically treated with zinc. Due to the paucity of literature data, little is known about the clinical course of individuals affected by MEDNIK syndrome, and the possible early association with epilepsy needs to be investigated. We present the first case of Italian origin affected by MEDNIK syndrome carrying a new homozygous AP1S1 stop variant, presenting with congenital severe enteropathy and feeding-related seizures, thus representing an early, singular manifestation of the disease. We describe her clinical course and the zinc acetate therapeutic experience. We also reviewed the literature focusing on clinical manifestations (especially neurological), brain neuroimaging and the symptom evolution of patients with AP1S1-related MEDNIK syndrome and discuss possible future therapeutic attempts. Full article

Background: The immunoglobulin superfamily member 1 (IGSF1) gene encodes for a transmembrane glycoprotein involved in crucial processes such as growth, metabolism, and reproductive function. Loss-of-Function (LOF) mutations in the IGSF1 gene have been reported to cause the X-linked IGSF1 deficiency syndrome, a rare genetic condition that primarily affects males, characterized by hypothyroidism, macroorchidism, delayed puberty, obesity, and infertility. Case Report: In this study, we identified a novel hemizygous nonsense IGSF1 variant c.1989G>A (p.Trp663Ter) in a male patient who initially presented with growth impairment and growth hormone deficiency (GHD), with a positive family history on the maternal lineage. Notably, the proband does not present with macroorchidism, a feature typically associated with IGSF1 deficiency. The variant was also found in his heterozygous sister, who presented with isolated growth hormone deficiency, and in his mother, who displayed hypertension and thyroid dysfunction but no significant growth impairment. Discussion: This phenotypic variability suggests a differential expression of IGSF1-related symptoms depending on zygosity and sex within the same family, probably explained by X-chromosome inactivation (XCI) in females, which can lead to varying degrees of functional IGSF1 expression in different tissues. Conclusions: This case highlights the intrafamilial phenotypic variability associated with IGSF1 mutations, illustrating differences between male and female carriers and highlighting the importance of genetic testing in patients with similar clinical presentations. Full article

Background and Clinical Significance: Familial short stature is a common reason for referral in clinical genetics. While often attributed to a single genetic cause, genetic heterogeneity can complicate diagnosis and management. This report describes a family in which three distinct pathogenic variants in SHOX, PDE4D and ACAN caused overlapping phenotypes of familial short stature. Case Presentation: Clinical, radiological and molecular data were collected retrospectively at the Reference Centre for Constitutional Bone Diseases at Montpellier University Hospital. Targeted gene panels, whole genome sequencing and Sanger sequencing were employed to identify pathogenic variants. Variant interpretation followed the guidelines of the American College of Medical Genetics. A pathogenic SHOX variant (c.452G>A; p.Ser151Asn) was identified in the proband and her mother, which is consistent with dyschondrosteosis. A de novo PDE4D variant (c.671C>T; p.Thr224Ile) was identified in a cousin presenting with syndromic acrodysostosis. An ACAN splice variant (c.6833-1G>A) was detected in several family members and is associated with short stature and skeletal anomalies. An individual carrying both the SHOX and ACAN variants exhibited a more severe phenotype, suggesting an additive effect. Conclusions: This case study highlights the importance of systematic molecular investigations in families with overlapping yet heterogeneous phenotypes. Comprehensive genetic familial analysis enables personalized care and accurate genetic counselling, particularly when multiple diagnoses coexist. A family history should not preclude molecular testing, since similar phenotypes can result from different genetic causes. Full article

Gene fusions involving NUTM1 have been increasingly recognized in hematologic malignancies, though their role in acute myeloid leukemia (AML) remains poorly understood. We retrospectively analyzed 565 unique AML patients with reported fusion results who underwent comprehensive next-generation sequencing (NGS) between March 2022 and December 2023. Among them, three novel in-frame NUTM1 fusion transcripts, LARP1::NUTM1, ARHGAP15::NUTM1, and GABPB1::NUTM1, were identified in three relapsed or refractory AML cases, all with monocytic differentiation. Ancillary studies included flow cytometry, cytogenetics, FISH, and comprehensive mutational profiling. All three patients eventually relapsed and succumbed to their disease, despite initial responses in one case. Each case also harbored co-occurring mutations associated with adverse prognosis, such as BCOR, ASXL1, and RUNX1. These findings suggest NUTM1 fusions in AML could represent a distinct molecular subset with potentially poor prognosis, warranting further functional and clinical investigation to clarify their biological and therapeutic significance. Full article

Amaranthus L. includes valuable and promising crops of multi-purpose use, having high morphological diversity and complicated taxonomy. Their karyotypes and genomic relationships remain insufficiently studied. For the first time, a comparative repeatome analysis of Amaranthus tricolor L., Amaranthus cruentus L., and Amaranthus hypochondriacus L. was performed based on the high-throughput sequencing data obtained via bioinformatic analyses using the RepeatExplorer2/TAREAN/DANTE_LTR pipelines. Interspecific variations in the abundance of Ty1 Copia and Ty3 Gypsy retroelements, DNA transposons, and ribosomal and satellite DNA (satDNA) were detected. Based on fluorescence in situ hybridization (FISH), chromosome mapping of 45S rDNA, 5S rDNA, and satDNAs AmC9 and AmC70, and unique karyograms of A. tricolor, A. cruentus, Amaranthus paniculatus L., and A. hypochondriacus were constructed. The analysis of the interspecies genome diversity/similarity in DNA repeat contents, sequences of the identified satDNAs, and chromosome distribution patterns of the studied molecular markers indicated that these species might also share a common evolutionary ancestor. However, the genomes of A. cruentus, A. paniculatus, and A. hypochondriacus were more similar compared to A. tricolor, which aligns with the previous phylogenetic data. Our results demonstrate that cytogenomic studies might provide important data on Amaranthus species relationships elucidating taxonomy and evolution of these valuable crops. Full article

Adaptor Protein-1 (AP-1) is a heterotetrameric essential for intracellular vesicular trafficking and polarized localization of somato-dendritic proteins in neurons. Variants in the AP1G1 gene, encoding the gamma-1 subunit of adaptor-related protein complex 1 (AP1γ1), have recently been associated with Usmani–Riazuddin syndrome (USRISD, MIM#619467), a very rare human genetic disorder characterized by intellectual disability (ID), speech and neurodevelopmental delays. Here we report a novel variant (c.196G>A; p.Gly66Arg) identified by exome sequencing analysis in a young girl showing overlapping clinical features with USRIS, such as motor and speech delay, intellectual disability and abnormal aggressive behavior. In silico analysis of the missense de novo variant suggested an alteration in AP1G1 protein folding. Patient’s fibroblasts have been studied with immunofluorescence techniques to analyze the intracellular distribution of AP-1. Zebrafish are widely regarded as an excellent vertebrate model for studying human disease pathogenesis, given their transparent embryonic development, ease of breeding, high genetic similarity to humans, and straightforward genetic manipulation. Leveraging these advantages, we investigated the phenotype, locomotor behavior, and CNS development in zebrafish embryos following the microinjection of human wild-type and mutated AP1G1 mRNAs at the one-cell stage. Knockout (KO) of the AP1G1 gene in zebrafish led to death at the gastrula stage. Lethality in the KO AP1G1 fish model was significantly rescued by injection of the human wild-type AP1G1 mRNA, but not by transcripts encoded by the Gly66Arg missense allele. The phenotype was also not rescued when ap1g1−/− zebrafish embryos were co-injected with both human wild-type and mutated mRNAs, supporting the dominant-negative effect of the new variant. In this study, we defined the effects of a new AP1G1 variant in cellular and animal models of Usmani–Riazzudin syndrome for future therapeutic approaches. Full article

Cervical cancer (CC) is the fourth most common cancer among women globally, with venous thromboembolism (VTE) representing a life-threatening complication. Cancer-associated thrombosis (CAT) arises from tumor-driven activation of hemostasis, worsening prognosis. Recently, circulating microRNAs (miRNAs) have emerged as potential biomarkers for both CAT and cervical tumorigenesis. Thus, this study aimed to assess the implications of five miRNAs—miR-20a-5p, -23a-3p, -125b-5p, -145-5p, and -616-3p—in CC-related VTE context. These miRNAs were quantified by RT-qPCR in plasma from 69 CC patients before treatment. Briefly, VTE occurred in nine patients, decreasing overall survival (OS) [log-rank test, p = 0.005; hazard ratio (HR) = 4.78; 95% confidence interval (CI), 1.42–16.05]. Lower miR-20a-5p levels predicted VTE (ꭓ² test, p = 0.027) and, in subgroup analyses, they were linked to cervical squamous cell carcinoma (CSCC) and older age (ꭓ² test, p = 0.003 and p = 0.043, respectively). In VTE patients, miR-145-5p downregulation was associated with improved OS (log-rank test, p = 0.018), an effect also observed in the adenocarcinoma (ADC) subgroup (log-rank test, p = 0.039). The remaining miRNAs showed subtype-specific links to clinicopathological features and survival. These findings highlight the potential value of circulating miRNAs in thrombotic risk and prognosis assessment in CC. Full article

The PML::RARA fusion resulting from t(15;17) is the genetic hallmark of acute promyelocytic leukemia (APL), typically detected by cytogenetics and/or fluorescence in situ hybridization (FISH) studies. Rarely, APL patients present with normal cytogenetics and FISH findings, complicating diagnosis and delaying life-saving therapy. We report a 23-year-old male with clinical, morphologic and immunophenotypic features consistent with APL but negative for FISH studies. Despite prompt initiation of all-trans retinoic acid (ATRA) based on clinical suspicion, the patient succumbed to intracranial hemorrhage. Quantitative reverse transcriptase PCR (qRT-PCR) confirmed a long isoform PML::RARA fusion. A review of 34 published cytogenetics- and FISH-negative cases since 1995 demonstrates that RT-PCR-based methods reliably detect cryptic fusions. While advanced genomic approaches may identify these fusions at higher resolution, their accessibility, complexity, cost, and turnaround time often limit diagnostic utility in the urgent setting of APL. Given the extreme rarity of this subset, cytogenetics and FISH remain the standard frontline tests; however, these cases underscore the critical need to incorporate molecular testing into routine workflows. Early recognition and timely therapy are essential to reducing mortality in cryptic APL, and these cases also provide insight into mechanisms of atypical leukemia biology. Full article

Background/Objectives: The etiology of congenital diaphragmatic hernia (CDH) remains unknown in over 50% of cases, although multiple heterogeneous causative defects have been identified. Emerging evidence suggests that specific genes and molecular pathways involved in connective tissue biology may contribute to CDH development. Associations between CDH and connective tissue disorders have been reported, including cases in Marfan syndrome and a prevalence of CDH in 34% of patients with arterial tortuosity syndrome. Noticing joint laxity in several CDH patients, we aimed to investigate the presence of genetic variants linked to connective tissue disorders in this subgroup, focusing on patients enrolled in the follow-up program at Bambino Gesù Children’s Hospital. Methods: We selected patients diagnosed with CDH who also exhibited joint laxity based on a positive Beighton scale. These individuals underwent molecular analysis targeting genes known to be associated with heritable connective tissue disorders. Results: Genetic testing revealed variants in several genes across our patient series. These included mutations in FBN1, FBN2, ZNF469, VEGFA, NOTCH1, ELN, MCTP2, and SMAD6. In some cases, the variants were inherited paternally, while others appeared de novo. Most of these variants were classified as of unknown significance according to ACMG guidelines. Conclusions: (1) Several “variants of unknown significance” in different genes causative for connective tissue disorders have been detected in half of the present series of patients with CDH and joint laxity; (2) although the majority of the variants are classified accordingly to the ACMG as “variants of unknown significance”, a role of predisposition or susceptibility to CDH cannot be excluded; (3) a precise clinical evaluation for features of connective disorders should be recommended in the diagnostic workflow of patients with CDH. Full article

Bats are great models for studying repetitive DNAs due to their compact genomes and extensive chromosomal rearrangements. Here, we investigated the repetitive DNA content of two phyllostomid bat species, Artibeus lituratus (2nn = 30♀/31♂) and Carollia perspicillata (2n = 20♀/21♂), both harboring a multiple XY₁Y₂ sex chromosome system. Satellite DNA (satDNA) libraries were isolated and characterized, revealing four and ten satDNA families in A. lituratus and C. perspicillata, respectively. These sequences, along with selected microsatellites, were in situ mapped onto chromosomes in both species and phylogenetically related taxa. SatDNAs showed strong accumulation in centromeric and subtelomeric regions, especially pericentromeric areas. Cross-species mapping with C. perspicillata-derived probes indicated terminal localization patterns in other bat species, suggesting conserved distribution. Microsatellites co-localized with 45S rDNA clusters on the neo-sex chromosomes. Additionally, genomic hybridization revealed a male-specific signal on the Y₁ chromosome, pointing to potential sex-linked repetitive regions. These findings confirm that bat genomes display relatively low amounts of repetitive DNA compared to other mammals and underscore the role of these elements in genome organization and sex chromosome evolution in phyllostomid bats. Full article