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Molecular analysis of individuals with suspected 46,XY differences of sex development in a homogenous and understudied population.

Differences of sex development (DSD) are a group of rare congenital conditions defined by atypical chromosomal, gonadal, and/or hormonal sex. Despite advances in massively parallel sequencing (MPS), more than half of DSD cases have an unknown genetic aetiology. We recruited and analysed 21 individuals with 46,XY DSD from the Greater Middle East population using chromosomal microarray and whole exome sequencing. Participants had DSD ranging from micropenis to anorchia (absence of testes) with extra-genital features reported in four individuals (19%). Using a combination of microarray and WES, a genetic diagnosis (variants curated as likely pathogenic or pathogenic) was identified in 12/21 (57%) individuals. Microarray analysis showed two DSD participants with extra genital features had chromosomal abnormalities (48,XXXY and mosaic Y chromosomal rearrangement). Microarray also indicated a high degree of consanguinity, with extensive long contiguous stretches of homozygosity (LCSH) (>3% of the genome) in 6/21 (28.6%) individuals, all of whom received a genetic diagnosis. WES analysis revealed variants in the NR5A1 (three individuals), SRD5A2 (three individuals), TALDO1 (one individual) and AR (two individuals) genes. This includes the novel frameshift variant, c.1309del (p.Leu437Cysfs*59), in NR5A1. This study contributes to the characterisation of clinical features and molecular findings in individuals with DSD in this understudied and homogenous population and highlights the challenges with DSD diagnosis in the region. The genetic diagnoses identified may contribute to improved patient care and management.

Humans

Host restriction of Salmonella enterica serotype Typhimurium pigeon isolates does not correlate with loss of discrete genes.

The definitive phage types (DT) 2 and 99 of Salmonella enterica serotype Typhimurium are epidemiologically correlated with a host range restricted to pigeons, in contrast to phage types with broader host ranges such as epidemic cattle isolates (DT104 and DT204). To determine whether phage types with broad host range possess genetic islands absent from host-restricted phage types, we compared the genomes of four pigeon isolates to serotype Typhimurium strain LT2 using a DNA microarray. Three of the four isolates tested caused fluid accumulation in bovine ligated ileal loops, but they had reduced colonization of liver and spleen in susceptible BALB/c mice and were defective for intestinal persistence in Salmonella-resistant CBA mice. The genomes of the DT99 and DT2 isolates were extremely similar to the LT2 genome, with few notable differences on the level of complete individual genes. Two large groups of genes representing the Fels-1 and Fels-2 prophages were missing from the DT2 and DT99 phage types we analyzed. One of the DT99 isolates examined was lacking a third cluster of five chromosomal genes (STM1555 to -1559). Results of the microarray analysis were extended using Southern analysis to a collection of 75 serotype Typhimurium clinical isolates of 24 different phage types. This analysis revealed no correlation between the presence of Fels-1, Fels-2, or STM1555 to -1559 and the association of phage types with different host reservoirs. We conclude that serotype Typhimurium phage types with broad host range do not possess genetic islands influencing host restriction, which are absent from the host-restricted pigeon isolates.

Animals

[Optical genome mapping analysis of a Chinese pedigree with a complex balanced translocation involving four chromosomes].

OBJECTIVE: To explore the genetic characteristics of a complex balanced translocation involving four non-homologous chromosomes in a Chinese pedigree using optical genomic mapping (OGM). METHODS: A woman with primary infertility and her family members who presented at the Prenatal Diagnosis Center of the Sixth Affiliated Hospital of Sun Yat-sen University in October 2021 were selected as study subjects. Comprehensive analysis and verification of chromosomal abnormalities were conducted through conventional G-band karyotyping analysis, single nucleotide polymorphism microarray (SNP array) and OGM. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: E2022210). RESULTS: G-band karyotyping analysis indicated that the proband, her father, and younger brother have all carried a complex translocation involving four chromosomes. SNP array analysis revealed a duplication of approximately 21.63 Mb in the 9p24.1-p21.1 region in the proband's younger brother, while no abnormality was detected in other family members. OGM confirmed that the complex balanced translocation has involved chromosomes 5, 8, 9, and 10. CONCLUSION: The proband has harbored a complex balanced translocation. OGM has demonstrated certain advantages in characterization of complex chromosomal structural abnormalities.

Humans

Construction of a 2-Mb resolution BAC microarray for CGH analysis of canine tumors.

Recognition of the domestic dog as a model for the comparative study of human genetic traits has led to major advances in canine genomics. The pathophysiological similarities shared between many human and dog diseases extend to a range of cancers. Human tumors frequently display recurrent chromosome aberrations, many of which are hallmarks of particular tumor subtypes. Using a range of molecular cytogenetic techniques we have generated evidence indicating that this is also true of canine tumors. Detailed knowledge of these genomic abnormalities has the potential to aid diagnosis, prognosis, and the selection of appropriate therapy in both species. We recently improved the efficiency and resolution of canine cancer cytogenetics studies by developing a small-scale genomic microarray comprising a panel of canine BAC clones representing subgenomic regions of particular interest. We have now extended these studies to generate a comprehensive canine comparative genomic hybridization (CGH) array that comprises 1158 canine BAC clones ordered throughout the genome with an average interval of 2 Mb. Most of the clones (84.3%) have been assigned to a precise cytogenetic location by fluorescence in situ hybridization (FISH), and 98.5% are also directly anchored within the current canine genome assembly, permitting direct translation from cytogenetic aberration to DNA sequence. We are now using this resource routinely for high-throughput array CGH and single-locus probe analysis of a range of canine cancers. Here we provide examples of the varied applications of this resource to tumor cytogenetics, in combination with other molecular cytogenetic techniques.

Animals

Genomic insights from a deeply phenotyped highly consanguineous neurodevelopmental disorders cohort.

PURPOSE: The genetic underpinning of neurodevelopmental disorders (NDDs) in diverse ethnic populations, especially those with high rates of consanguinity, remains largely unexplored. Here, we aim to elucidate genomic insight from 576 well-phenotyped and highly consanguineous (16%) NDD cohort. METHODS: We used chromosomal microarray (CMA; N:247), exome sequencing (ES; N:127), combined CMA and ES (N:202), and long-read genome sequencing to identify genetic etiology. Deep clinical multivariate data were coupled with genomic variants for stratification analysis. RESULTS: Genetic diagnosis rates were 17% with CMA, 29.92% with ES, and 37.13% with combined CMA and ES. Notably, children of consanguineous parents showed a significantly higher diagnostic yield (P < .01) compared to those from nonconsanguineous parents. Among the ES-identified pathogenic variants, 36.19% (38/105) were novel, implicating 35 unique genes. Long-read sequencing of seizure participants unresolved by combined test identified expanded FMR1 trinucleotide repeats. Additionally, we identified 2 recurrent X-linked variants in the G6PD in 3.65% (12/329) of NDD participants. These variants were absent in large-population control cohorts and cohort comprising neurodevelopmental and neuropsychiatric populations of European descendants, indicating a possible associated risk factor potentially resulting from ancient genetic drift. CONCLUSION: This study unveils unique clinical and genomic insights from a consanguinity rich Bangladeshi NDD cohort.

Humans

Assessment of Gene Set Enrichment Analysis using curated RNA-seq-based benchmarks.

Pathway enrichment analysis is a ubiquitous computational biology method to interpret a list of genes (typically derived from the association of large-scale omics data with phenotypes of interest) in terms of higher-level, predefined gene sets that share biological function, chromosomal location, or other common features. Among many tools developed so far, Gene Set Enrichment Analysis (GSEA) stands out as one of the pioneering and most widely used methods. Although originally developed for microarray data, GSEA is nowadays extensively utilized for RNA-seq data analysis. Here, we quantitatively assessed the performance of a variety of GSEA modalities and provide guidance in the practical use of GSEA in RNA-seq experiments. We leveraged harmonized RNA-seq datasets available from The Cancer Genome Atlas (TCGA) in combination with large, curated pathway collections from the Molecular Signatures Database to obtain cancer-type-specific target pathway lists across multiple cancer types. We carried out a detailed analysis of GSEA performance using both gene-set and phenotype permutations combined with four different choices for the Kolmogorov-Smirnov enrichment statistic. Based on our benchmarks, we conclude that the classic/unweighted gene-set permutation approach offered comparable or better sensitivity-vs-specificity tradeoffs across cancer types compared with other, more complex and computationally intensive permutation methods. Finally, we analyzed other large cohorts for thyroid cancer and hepatocellular carcinoma. We utilized a new consensus metric, the Enrichment Evidence Score (EES), which showed a remarkable agreement between pathways identified in TCGA and those from other sources, despite differences in cancer etiology. This finding suggests an EES-based strategy to identify a core set of pathways that may be complemented by an expanded set of pathways for downstream exploratory analysis. This work fills the existing gap in current guidelines and benchmarks for the use of GSEA with RNA-seq data and provides a framework to enable detailed benchmarking of other RNA-seq-based pathway analysis tools.

Humans

Uncovering hub genes and key pathways responsive to drought stress in rice via meta-analysis of transcriptomic data.

Drought stress presents a formidable threat to global rice cultivation, triggering complex molecular responses that impact plant growth and productivity. To decipher the underlying gene expression dynamics, we performed a comprehensive meta-analysis of transcriptomic datasets derived from drought-tolerant rice genotypes. Via microarray data from three independent studies, we identified a set of consistently expressed differentially expressed genes (DEGs) under drought conditions. Integration of functional annotation tools, including GO and KEGG pathway enrichment, revealed key biological processes and signaling cascades involved in stress mitigation, such as ABA signaling, protein folding, and photosynthesis suppression. Protein-protein interaction (PPI) network construction, followed by hub gene identification via maximal clique centrality (MCC), highlighted pivotal regulators including LEA proteins, dehydrins, HSP70, and several transcription factors. Machine learning approaches further prioritize potential biomarkers, with Random Forest models achieving high classification accuracy and pinpointing key predictive genes. Chromosomal localization analysis provided spatial insights into the distribution of these hub genes, whose expression patterns were further compared against qRT-PCR data from previously published studies. This integrative approach identifies candidate genomic markers and mechanistic insights that may support future breeding strategies for drought-tolerant rice, pending experimental validation.

Cytoscape

Widespread Loss of Heterozygosity and Endoreduplication in Odontogenic Myxoma: Expanding the Clinicopathologic Spectrum of An Enigmatic Odontogenic Neoplasm.

Odontogenic myxoma (OM) is an uncommon, locally aggressive odontogenic neoplasm with characteristic histologic and clinico-radiographic features but with potential for histologic overlap with other odontogenic and non-odontogenic entities and a non-specific immunoprofile. Widespread loss of heterozygosity (LOH) has been recently described in rare cases of OM. The aim of this study was to determine whether widespread LOH represents a recurrent molecular signature that can be leveraged for clinical decision-making. Allele-specific copy number variation data from chromosomal microarray were generated from 7 OM, comprising a combined prospective and retrospective cohort. Four tumors arose in the mandible and 3 in the maxilla in patients ranging in age from 18 to 94 years (median: 44), with tumor size ranging from 2.2 to 13.0&#xa0;cm. Variable amounts of fibrous stroma (odontogenic "fibromyxoma") were present in 4/7 OM, and hypercellularity not typically appreciated in conventional OM was present in 3/7 cases. All OM (7/7) demonstrated widespread LOH, with 5 cases showing a near-haploid/low hypodiploid genomes (multiple monosomies) and 2 cases showing evidence of pseudo-hyperdiploidy due to probable endoreduplication. Both pseudo-hyperdiploid cases were &#x2265;10&#xa0;cm in size; 1 represented local recurrence. Chromosomes 1 to 3, 6, 9, 11, 13, 15, and 22 demonstrated LOH in &#x2265;75% of cases (chromosomes 1 to 3, 6, and 9 in 100% of cases), while chromosomes 5, 12, 19, and 20 universally retained heterozygosity. Altogether, widespread LOH is a recurrent event in OM and a novel finding in odontogenic pathology, and allele-specific copy number variation analysis can serve as a diagnostic adjunct in challenging cases.

copy number variation

Genomic mapping of diabetic kidney disease biomarkers and identification of potential inhibitors through virtual screening.

BACKGROUND: Diabetic kidney disease (DKD) is a common and serious complication of diabetes mellitus, marked by a multifactorial pathogenesis and the absence of sensitive diagnostic biomarkers. Identifying novel molecular targets and therapeutic options is essential to improve early diagnosis and treatment outcomes. METHODS: To uncover potential biomarkers and therapeutic candidates, we performed an integrated genomic analysis using microarray and RNA-seq datasets from the Gene Expression Omnibus (GEO) and Sequence Read Archive (SRA) databases. Differentially expressed genes (DEGs) were identified and subjected to protein-protein interaction (PPI) network analysis. Key genes were further explored through virtual screening of an FDA-approved compound library using molecular docking techniques. Drug-likeness was assessed via Lipinski's rule of five. RESULTS: A total of 40 DEGs were identified, among which ISCU (downregulated; involved in iron-sulfur cluster biogenesis) and AP1S2 (upregulated; associated with vesicular trafficking) emerged as potential biomarkers. PPI analysis revealed their involvement in critical DKD-related pathways, such as extracellular matrix remodeling and oxidative stress. Virtual screening identified six FDA-approved compounds with high binding affinity (&#x2264;-7.96 kcal/mol) to ISCU, notably ZINC000001576020, all of which complied with Lipinski's rule. CONCLUSIONS: This in-silico study nominates ISCU and AP1S2 as candidate diagnostic biomarkers for DKD and identifies computationally prioritized inhibitors targeting ISCU. These findings require experimental validation but provide a molecular framework for precision diagnosis and therapeutic development. These findings offer new molecular insights that could inform precision diagnosis and personalized treatment strategies for diabetic kidney disease.

Diabetic Nephropathies

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 Ni&#xf1;o. 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&#xa0;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&#x2009;=&#x2009;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