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1.
BMC Genomics ; 25(1): 371, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627676

RESUMO

BACKGROUND: X-chromosome inactivation (XCI) is an epigenetic process that occurs during early development in mammalian females by randomly silencing one of two copies of the X chromosome in each cell. The preferential inactivation of either the maternal or paternal copy of the X chromosome in a majority of cells results in a skewed or non-random pattern of X inactivation and is observed in over 25% of adult females. Identifying skewed X inactivation is of clinical significance in patients with suspected rare genetic diseases due to the possibility of biased expression of disease-causing genes present on the active X chromosome. The current clinical test for the detection of skewed XCI relies on the methylation status of the methylation-sensitive restriction enzyme (Hpall) binding site present in proximity of short tandem polymorphic repeats on the androgen receptor (AR) gene. This approach using one locus results in uninformative or inconclusive data for 10-20% of tests. Further, recent studies have shown inconsistency between methylation of the AR locus and the state of inactivation of the X chromosome. Herein, we develop a method for estimating X inactivation status, using exome and transcriptome sequencing data derived from blood in 227 female samples. We built a reference model for evaluation of XCI in 135 females from the GTEx consortium. We tested and validated the model on 11 female individuals with different types of undiagnosed rare genetic disorders who were clinically tested for X-skew using the AR gene assay and compared results to our outlier-based analysis technique. RESULTS: In comparison to the AR clinical test for identification of X inactivation, our method was concordant with the AR method in 9 samples, discordant in 1, and provided a measure of X inactivation in 1 sample with uninformative clinical results. We applied this method on an additional 81 females presenting to the clinic with phenotypes consistent with different hereditary disorders without a known genetic diagnosis. CONCLUSIONS: This study presents the use of transcriptome and exome sequencing data to provide an accurate and complete estimation of X-inactivation and skew status in a cohort of female patients with different types of suspected rare genetic disease.


Assuntos
Exoma , Inativação do Cromossomo X , Adulto , Humanos , Feminino , Transcriptoma , Sequenciamento do Exoma , Cromossomos Humanos X/genética
2.
Cell Mol Life Sci ; 81(1): 194, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38653846

RESUMO

Sex chromosome aneuploidies are among the most common variations in human whole chromosome copy numbers, with an estimated prevalence in the general population of 1:400 to 1:1400 live births. Unlike whole-chromosome aneuploidies of autosomes, those of sex chromosomes, such as the 47, XXY aneuploidy that causes Klinefelter Syndrome (KS), often originate from the paternal side, caused by a lack of crossover (CO) formation between the X and Y chromosomes. COs must form between all chromosome pairs to pass meiotic checkpoints and are the product of meiotic recombination that occurs between homologous sequences of parental chromosomes. Recombination between male sex chromosomes is more challenging compared to both autosomes and sex chromosomes in females, as it is restricted within a short region of homology between X and Y, called the pseudo-autosomal region (PAR). However, in normal individuals, CO formation occurs in PAR with a higher frequency than in any other region, indicating the presence of mechanisms that promote the initiation and processing of recombination in each meiotic division. In recent years, research has made great strides in identifying genes and mechanisms that facilitate CO formation in the PAR. Here, we outline the most recent and relevant findings in this field. XY chromosome aneuploidy in humans has broad-reaching effects, contributing significantly also to Turner syndrome, spontaneous abortions, oligospermia, and even infertility. Thus, in the years to come, the identification of genes and mechanisms beyond XY aneuploidy is expected to have an impact on the genetic counseling of a wide number of families and adults affected by these disorders.


Assuntos
Pareamento Cromossômico , Segregação de Cromossomos , Meiose , Humanos , Animais , Pareamento Cromossômico/genética , Masculino , Meiose/genética , Camundongos , Segregação de Cromossomos/genética , Feminino , Aneuploidia , Cromossomos Humanos X/genética , Cromossomos Humanos Y/genética , Cromossomos Sexuais/genética , Troca Genética/genética
3.
Sci Rep ; 14(1): 7369, 2024 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-38548827

RESUMO

Tandem repeat genetic profiles used in forensic applications varies between populations. Despite the diversity and security issues in the Sahel that require the identification of victims (soldiers and civilians), Burkina Faso (BF) remains understudied. To fill this information gap, 396 unrelated individuals from BF were genotyped using a MICROREADER 21 ID System kit. All 20 short tandem repeat (STR) loci tested passed the Hardy-Weinberg equilibrium (HWE) test. The combined powers of exclusion for duos (CPE duos) and trios (CPE trios) for the 20 tested loci were 0.9999998 and 0.9999307, respectively. The probability that two individuals would share the same DNA profiles among the BF population was 9.80898 × 10-26. For the X-chromosome STR analysis, 292 individuals were included in this study using a MICROREADER 19X Direct ID System kit. Among the 19 loci, no significant deviations from HWE test were observed in female samples after Bonferroni correction (p < 0.05/19 = 0.0026), except for loci GATA165B12 and DXS7423. The results showed that the combined power of exclusion (CPE) and the combined power of discrimination in females (CPDF) and males (CPDM) were 0.999999760893, 0.999999999992, and 1, respectively. Comparison with other African sub-populations showed that geographical proximity is a reliable indicator of genetic relatedness.


Assuntos
Cromossomos Humanos X , Genética Populacional , Masculino , Humanos , Feminino , Frequência do Gene , Burkina Faso , Cromossomos Humanos X/genética , Repetições de Microssatélites/genética , China
4.
Cell Mol Life Sci ; 81(1): 156, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38551746

RESUMO

X chromosome inactivation (XCI) is a process that equalizes the expression of X-linked genes between males and females. It relies on Xist, continuously expressed in somatic cells during XCI maintenance. However, how Xist impacts XCI maintenance and its functional motifs remain unclear. In this study, we conducted a comprehensive analysis of Xist, using rabbits as an ideal non-primate model. Homozygous knockout of exon 1, exon 6, and repeat A in female rabbits resulted in embryonic lethality. However, X∆ReAX females, with intact X chromosome expressing Xist, showed no abnormalities. Interestingly, there were no significant differences between females with homozygous knockout of exons 2-5 and wild-type rabbits, suggesting that exons 2, 3, 4, and 5 are less important for XCI. These findings provide evolutionary insights into Xist function.


Assuntos
RNA Longo não Codificante , Inativação do Cromossomo X , Humanos , Masculino , Animais , Coelhos , Feminino , Inativação do Cromossomo X/genética , RNA Longo não Codificante/genética , Cromossomos Humanos X , Cromossomo X/genética , Éxons/genética
5.
Nature ; 628(8008): 648-656, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38538789

RESUMO

Dynamically organized chromatin complexes often involve multiplex chromatin interactions and sometimes chromatin-associated RNA1-3. Chromatin complex compositions change during cellular differentiation and ageing, and are expected to be highly heterogeneous among terminally differentiated single cells4-7. Here we introduce the multinucleic acid interaction mapping in single cells (MUSIC) technique for concurrent profiling of multiplex chromatin interactions, gene expression and RNA-chromatin associations within individual nuclei. When applied to 14 human frontal cortex samples from older donors, MUSIC delineated diverse cortical cell types and states. We observed that nuclei exhibiting fewer short-range chromatin interactions were correlated with both an 'older' transcriptomic signature and Alzheimer's disease pathology. Furthermore, the cell type exhibiting chromatin contacts between cis expression quantitative trait loci and a promoter tends to be that in which these cis expression quantitative trait loci specifically affect the expression of their target gene. In addition, female cortical cells exhibit highly heterogeneous interactions between XIST non-coding RNA and chromosome X, along with diverse spatial organizations of the X chromosomes. MUSIC presents a potent tool for exploration of chromatin architecture and transcription at cellular resolution in complex tissues.


Assuntos
Envelhecimento , Núcleo Celular , Cromatina , Lobo Frontal , RNA , Análise de Célula Única , Idoso , Feminino , Humanos , Masculino , Envelhecimento/genética , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Núcleo Celular/genética , Senescência Celular/genética , Cromatina/genética , Cromatina/metabolismo , Cromossomos Humanos X/genética , Cromossomos Humanos X/metabolismo , Lobo Frontal/metabolismo , Perfilação da Expressão Gênica/métodos , Regiões Promotoras Genéticas , Locos de Características Quantitativas , RNA/genética , RNA/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Análise de Célula Única/métodos , Transcrição Gênica
6.
Lupus Sci Med ; 11(1)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38458775

RESUMO

OBJECTIVES: X chromosome has been considered as a risk factor for SLE, which is a prototype of autoimmune diseases with a significant sex difference (female:male ratio is around 9:1). Our study aimed at exploring the association of genetic variants in X chromosome and investigating the influence of trisomy X in the development of SLE. METHODS: X chromosome-wide association studies were conducted using data from both Thai (835 patients with SLE and 2995 controls) and Chinese populations (1604 patients with SLE and 3324 controls). Association analyses were performed separately in females and males, followed by a meta-analysis of the sex-specific results. In addition, the dosage of X chromosome in females with SLE were also examined. RESULTS: Our analyses replicated the association of TMEM187-IRAK1-MECP2, TLR7, PRPS2 and GPR173 loci with SLE. We also identified two loci suggestively associated with SLE. In addition, making use of the difference in linkage disequilibrium between Thai and Chinese populations, a synonymous variant in TMEM187 was prioritised as a likely causal variant. This variant located in an active enhancer of immune-related cells, with the risk allele associated with decreased expression level of TMEM187. More importantly, we identified trisomy X (47,XXX) in 5 of 2231 (0.22%) females with SLE. The frequency is significantly higher than that found in the female controls (0.08%; two-sided exact binomial test P=0.002). CONCLUSION: Our study confirmed previous SLE associations in X chromosome, and identified two loci suggestively associated with SLE. More importantly, our study indicated a higher risk of SLE for females with trisomy X.


Assuntos
Lúpus Eritematoso Sistêmico , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual , Trissomia , Humanos , Masculino , Feminino , Lúpus Eritematoso Sistêmico/epidemiologia , Lúpus Eritematoso Sistêmico/genética , Predisposição Genética para Doença , Tailândia/epidemiologia , Aberrações dos Cromossomos Sexuais , Cromossomos Humanos X/genética , China , Proteínas de Membrana
7.
Front Endocrinol (Lausanne) ; 15: 1324160, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38481442

RESUMO

Purpose: Analyze the relationship between changes in the proportion of X-chromosome deletions and clinical manifestations in children with Turner syndrome (TS). Methods: X-chromosome number abnormalities in 8,635 children with growth retardation were identified using fluorescence in situ hybridization (FISH). Meanwhile, the relationship between the proportion of X-chromosome deletions and the clinical manifestations of TS, such as face and body phenotype, cardiovascular, renal, and other comorbidities in children with TS was analyzed. Results: A total of 389 children had X-chromosome number abnormalities, with an average age at diagnosis of 9.2 years. There was a significant increase in diagnoses around the ages of 3 and 7 years and highest number of diagnoses at 10 years of age. 130 with XO (complete loss of an X-chromosome), 205 with XO/XX, 8 with XO/XXX, 23 with XO/XX/XXX, 19 with XO/XY, and 4 with XO/XY/XYY. Body and facial phenotypes increased with higher mosaicism proportions, with a relatively high correlation shown with Pearson correlation analysis (r = 0.26, p = 1.7e-06). The incidence of congenital heart malformations was 25.56%, mainly involving a bicuspid aortic valve, and were more common in patients who had complete loss of an X-chromosome. However, this relationship was not present for renal disease (p = 0.26), central nervous system, thyroid, or liver disease. Conclusion: The mosaicism (XO/XX) is the most common karyotype of TS in screened cases. The phenotypes in children with TS may increase with the proportion of X-chromosome deletions, but the renal disease and comorbidities did not show the same characteristics.


Assuntos
Nefropatias , Síndrome de Turner , Criança , Humanos , Síndrome de Turner/complicações , Síndrome de Turner/epidemiologia , Síndrome de Turner/genética , Deleção Cromossômica , Hibridização in Situ Fluorescente , Cromossomos Humanos X/genética , Cariotipagem , Nefropatias/genética
8.
J Neurodev Disord ; 16(1): 5, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38424476

RESUMO

X-linked genetic causes of intellectual disability (ID) account for a substantial proportion of cases and remain poorly understood, in part due to the heterogeneous expression of X-linked genes in females. This is because most genes on the X chromosome are subject to random X chromosome inactivation (XCI) during early embryonic development, which results in a mosaic pattern of gene expression for a given X-linked mutant allele. This mosaic expression produces substantial complexity, especially when attempting to study the already complicated neural circuits that underly behavior, thus impeding the understanding of disease-related pathophysiology and the development of therapeutics. Here, we review a few selected X-linked forms of ID that predominantly affect heterozygous females and the current obstacles for developing effective therapies for such disorders. We also propose a genetic strategy to overcome the complexity presented by mosaicism in heterozygous females and highlight specific tools for studying synaptic and circuit mechanisms, many of which could be shared across multiple forms of intellectual disability.


Assuntos
Deficiência Intelectual , Feminino , Humanos , Gravidez , Cromossomos Humanos X , Genes Ligados ao Cromossomo X/genética , Deficiência Intelectual/genética , Mosaicismo , Inativação do Cromossomo X/genética
9.
Genes (Basel) ; 15(2)2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38397149

RESUMO

Repetitive sequences form a substantial and still enigmatic part of the mammalian genome. We isolated repetitive DNA blocks of the X chromosomes of three species of the family Bovidae: Kobus defassa (KDEXr sequence), Bos taurus (BTAXr sequence) and Antilope cervicapra (ACEXr sequence). The copy numbers of the isolated sequences were assessed using qPCR, and their chromosomal localisations were analysed using FISH in ten bovid tribes and in outgroup species. Besides their localisation on the X chromosome, their presence was also revealed on the Y chromosome and autosomes in several species. The KDEXr sequence abundant in most Bovidae species also occurs in distant taxa (Perissodactyla and Carnivora) and seems to be evolutionarily older than BTAXr and ACEXr. The ACEXr sequence, visible only in several Antilopini species using FISH, is probably the youngest, and arised in an ancestor common to Bovidae and Cervidae. All three repetitive sequences analysed in this study are interspersed among gene-rich regions on the X chromosomes, apparently preventing the crossing-over in their close vicinity. This study demonstrates that repetitive sequences on the X chromosomes have undergone a fast evolution, and their variation among related species can be beneficial for evolutionary studies.


Assuntos
Antílopes , Cervos , Bovinos/genética , Animais , Humanos , Sequências Repetitivas de Ácido Nucleico/genética , Cervos/genética , Cromossomo Y/genética , DNA , Antílopes/genética , Cromossomos Humanos X
10.
Mol Biol Evol ; 41(2)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38306314

RESUMO

Allele-specific gene expression evolves rapidly on heteromorphic sex chromosomes. Over time, the accumulation of mutations on the Y chromosome leads to widespread loss of gametolog expression, relative to the X chromosome. It remains unclear if expression evolution on degrading Y chromosomes is primarily driven by mutations that accumulate through processes of selective interference, or if positive selection can also favor the down-regulation of coding regions on the Y chromosome that contain deleterious mutations. Identifying the relative rates of cis-regulatory sequence evolution across Y chromosomes has been challenging due to the limited number of reference assemblies. The threespine stickleback (Gasterosteus aculeatus) Y chromosome is an excellent model to identify how regulatory mutations accumulate on Y chromosomes due to its intermediate state of divergence from the X chromosome. A large number of Y-linked gametologs still exist across 3 differently aged evolutionary strata to test these hypotheses. We found that putative enhancer regions on the Y chromosome exhibited elevated substitution rates and decreased polymorphism when compared to nonfunctional sites, like intergenic regions and synonymous sites. This suggests that many cis-regulatory regions are under positive selection on the Y chromosome. This divergence was correlated with X-biased gametolog expression, indicating the loss of expression from the Y chromosome may be favored by selection. Our findings provide evidence that Y-linked cis-regulatory regions exhibit signs of positive selection quickly after the suppression of recombination and allow comparisons with recent theoretical models that suggest the rapid divergence of regulatory regions may be favored to mask deleterious mutations on the Y chromosome.


Assuntos
Evolução Molecular , Smegmamorpha , Humanos , Animais , Cromossomo Y/genética , Cromossomos Sexuais , Cromossomos Humanos Y , Cromossomos Humanos X , Smegmamorpha/genética
11.
Genetics ; 226(4)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38366786

RESUMO

The X chromosome, being hemizygous in males, is exposed one-third of the time increasing the visibility of new mutations to natural selection, potentially leading to different evolutionary dynamics than autosomes. Recently, we found an enrichment of hard selective sweeps over soft selective sweeps on the X chromosome relative to the autosomes in a North American population of Drosophila melanogaster. To understand whether this enrichment is a universal feature of evolution on the X chromosome, we analyze diversity patterns across 6 commonly studied Drosophila species. We find an increased proportion of regions with steep reductions in diversity and elevated homozygosity on the X chromosome compared to autosomes. To assess if these signatures are consistent with positive selection, we simulate a wide variety of evolutionary scenarios spanning variations in demography, mutation rate, recombination rate, background selection, hard sweeps, and soft sweeps and find that the diversity patterns observed on the X are most consistent with hard sweeps. Our findings highlight the importance of sex chromosomes in driving evolutionary processes and suggest that hard sweeps have played a significant role in shaping diversity patterns on the X chromosome across multiple Drosophila species.


Assuntos
Drosophila melanogaster , Drosophila , Humanos , Masculino , Animais , Drosophila/genética , Drosophila melanogaster/genética , Evolução Molecular , Cromossomo X/genética , Seleção Genética , Cromossomos Humanos X
12.
Nat Commun ; 15(1): 1165, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38326311

RESUMO

The t(X,17) chromosomal translocation, generating the ASPSCR1::TFE3 fusion oncoprotein, is the singular genetic driver of alveolar soft part sarcoma (ASPS) and some Xp11-rearranged renal cell carcinomas (RCCs), frustrating efforts to identify therapeutic targets for these rare cancers. Here, proteomic analysis identifies VCP/p97, an AAA+ ATPase with known segregase function, as strongly enriched in co-immunoprecipitated nuclear complexes with ASPSCR1::TFE3. We demonstrate that VCP is a likely obligate co-factor of ASPSCR1::TFE3, one of the only such fusion oncoprotein co-factors identified in cancer biology. Specifically, VCP co-distributes with ASPSCR1::TFE3 across chromatin in association with enhancers genome-wide. VCP presence, its hexameric assembly, and its enzymatic function orchestrate the oncogenic transcriptional signature of ASPSCR1::TFE3, by facilitating assembly of higher-order chromatin conformation structures demonstrated by HiChIP. Finally, ASPSCR1::TFE3 and VCP demonstrate co-dependence for cancer cell proliferation and tumorigenesis in vitro and in ASPS and RCC mouse models, underscoring VCP's potential as a novel therapeutic target.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Animais , Camundongos , Humanos , Proteômica , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Translocação Genética , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Neoplasias Renais/genética , Cromatina/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Cromossomos Humanos X/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteína com Valosina/genética
14.
J Appl Genet ; 65(2): 395-398, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38368284

RESUMO

A 9-year-old Thoroughbred mare with normal external genitalia and regular oestrus symptoms was gynecologically examined prior to insemination. This primary examination revealed the presence of a hypoplastic uterus and the lack of normal ovaries, and the mare was therefore subjected to more detailed diagnostics, including endocrinological, genetic, and clinical tests. Diagnostic imaging with the use of ultrasonography and endoscopy confirmed the underdevelopment of internal genitalia. Analysis of circulating sex hormones revealed very low concentrations of progesterone and oestradiol. Finally, cytogenetic analysis showed the presence of non-mosaic X trisomy (65,XXX), an aneuploidy of sex chromosomes that is rarely detected in horses. This finding was also confirmed by molecular methods, including highly sensitive droplet digital PCR (ddPCR) and microsatellite markers genotyping. Our study reveals the need for gynaecological and genetic evaluation of broodmares, even if their phenotype (including developed external genitalia and oestrus symptoms) shows no signs of potential abnormalities.


Assuntos
Aberrações dos Cromossomos Sexuais , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual , Trissomia , Humanos , Feminino , Cavalos/genética , Animais , Trissomia/genética , Aberrações dos Cromossomos Sexuais/veterinária , Cromossomos Humanos X , Análise Citogenética
15.
Aging (Albany NY) ; 16(2): 1696-1711, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38261736

RESUMO

OBJECTIVE: This study aims to establish an effective predictive model for predicting Xp11.2 translocation/TFE3 gene fusion renal cell carcinoma (TFE3-RCC) and develop optimal therapeutic strategies. METHODS: Data from 4961 patients diagnosed with renal cell carcinoma at two medical centers in China were retrospectively analyzed. A cohort of 1571 patients from Zhejiang Provincial People's Hospital (Ra cohort) was selected to construct the model. Another cohort of 1124 patients from the Second Affiliated Hospital of Zhejiang Chinese Medical University was used for external validation (the Ha cohort). All patients with TFE3-RCC in both cohorts were included in the Ta cohort for the prognostic analysis. Univariate and multivariate binary logistic regression analyses were performed to identify independent predictors of the predictive nomogram. The apparent performance of the model was validated. Decision curve analysis was also performed to assess the clinical utility of the developed model. Factors associated with progression and prognosis in the Ta cohort were analyzed using the log-rank method, and Cox regression analysis and Kaplan-Meier survival curves were used to describe the effects of factors on prognosis and progression. RESULTS: Univariate and multivariate logistic regression analyses demonstrated that age, sex, BMI, smoking, eosinophils, and LDL were independent predictors of TFE3-RCC. Therefore, a predictive nomogram for TFE3-RCC, which had good discriminatory power (AUC = 0.796), was constructed. External validation (AUC = 0.806) also revealed good predictive ability. The calibration curves displayed good consistency between the predicted and observed incidences of TFE3-RCC. Invasion of regional lymph nodes, tyrosine kinase inhibitors, and surgical methods were independent factors associated with progression. Tyrosine kinase inhibitors are independent prognostic factors. CONCLUSION: This study not only proposed a high-precision clinical prediction model composed of various variables for the early diagnosis of Xp11.2 translocation/TFE3 gene fusion renal cell carcinoma but also optimized therapeutic strategies through prognostic analysis.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/patologia , Neoplasias Renais/genética , Neoplasias Renais/patologia , Estudos Retrospectivos , Modelos Estatísticos , Translocação Genética , Prognóstico , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Cromossomos Humanos X/genética , Fusão Gênica
16.
Yi Chuan ; 46(1): 18-33, 2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38230454

RESUMO

X chromosome inactivation can balance the effects of the two X chromosomes in females, and emerging evidence indicates that numerous genes on the inactivated X chromosome have the potential to evade inactivation. The mechanisms of escape include modification of DNA, RNA, histone, epitope, and various regulatory proteins, as well as the spatial structure of chromatin. The study of X chromosome inactivation escape has paved the way for investigating sex dimorphism in human diseases, particularly autoimmune diseases. It has been demonstrated that the presence of TLR7, CD40L, IRAK-1, CXCR3, and CXorf21 significantly contributes to the prevalence of SLE (systemic lupus erythematosus) in females. This article mainly reviews the molecular mechanisms underlying these genes that escape from X-chromosome inactivation and sexual dimorphism of systemic lupus erythematosus. Therefore, elucidating the molecular mechanisms underlying sexual dimorphism in SLE is not only crucial for diagnosing and treating the disease, but also holds theoretical significance in comprehensively understanding the development and regulatory mechanisms of the human immune system.


Assuntos
Lúpus Eritematoso Sistêmico , Inativação do Cromossomo X , Feminino , Humanos , Inativação do Cromossomo X/genética , Caracteres Sexuais , Lúpus Eritematoso Sistêmico/genética , Cromossomos Humanos X/genética , Sistema Imunitário
17.
Sci Rep ; 14(1): 440, 2024 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-38172222

RESUMO

Menkes disease is an X-linked disorder of copper metabolism caused by mutations in the ATP7A gene, and female carriers are usually asymptomatic. We describe a 7-month-old female patient with severe intellectual disability, epilepsy, and low levels of serum copper and ceruloplasmin. While heterozygous deletion of exons 16 and 17 of the ATP7A gene was detected in the proband, her mother, and her grandmother, only the proband suffered from Menkes disease clinically. Intriguingly, X chromosome inactivation (XCI) analysis demonstrated that the grandmother and the mother showed skewing of XCI toward the allele with the ATP7A deletion and that the proband had extremely skewed XCI toward the normal allele, resulting in exclusive expression of the pathogenic ATP7A mRNA transcripts. Expression bias analysis and recombination mapping of the X chromosome by the combination of whole genome and RNA sequencing demonstrated that meiotic recombination occurred at Xp21-p22 and Xq26-q28. Assuming that a genetic factor on the X chromosome enhanced or suppressed XCI of its allele, the factor must be on either of the two distal regions derived from her grandfather. Although we were unable to fully uncover the molecular mechanism, we concluded that unfavorable switching of skewed XCI caused Menkes disease in the proband.


Assuntos
Síndrome dos Cabelos Torcidos , Humanos , Lactente , Feminino , Síndrome dos Cabelos Torcidos/genética , Inativação do Cromossomo X/genética , Cobre/metabolismo , Cromossomos Humanos X/genética , Mutação
18.
Cell Genom ; 4(1): 100462, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38190107

RESUMO

Somatic cells of human males and females have 45 chromosomes in common, including the "active" X chromosome. In males the 46th chromosome is a Y; in females it is an "inactive" X (Xi). Through linear modeling of autosomal gene expression in cells from individuals with zero to three Xi and zero to four Y chromosomes, we found that Xi and Y impact autosomal expression broadly and with remarkably similar effects. Studying sex chromosome structural anomalies, promoters of Xi- and Y-responsive genes, and CRISPR inhibition, we traced part of this shared effect to homologous transcription factors-ZFX and ZFY-encoded by Chr X and Y. This demonstrates sex-shared mechanisms by which Xi and Y modulate autosomal expression. Combined with earlier analyses of sex-linked gene expression, our studies show that 21% of all genes expressed in lymphoblastoid cells or fibroblasts change expression significantly in response to Xi or Y chromosomes.


Assuntos
Fatores de Transcrição , Cromossomo Y , Humanos , Masculino , Feminino , Fatores de Transcrição/genética , Cromossomos Humanos X/genética , Aberrações dos Cromossomos Sexuais , Expressão Gênica/genética
19.
Clin Chim Acta ; 554: 117770, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38199578

RESUMO

OBJECTIVE: To explore the impact of maternal factors on the false-positive fetal sex chromosome aneuploidies (SCAs) results obtained through noninvasive prenatal screening (NIPS). METHODS: We retrospectively analyzed pregnant women with high-risk SCAs as revealed using NIPS between January 2017 and December 2022. Clinical data such as results of invasive prenatal diagnoses, copy number variation sequencing (CNV-seq) and pregnancy outcomes were analysed. RESULTS: Overall, 177 (0.6 %) women with SCA-positive results were collected from 27,941 patients who had undergone NIPS. Among them, 110 (62.2 %) pregnant women chose prenatal diagnosis and 39 (35.5 %) cases were confirmed. For the women with monosomy X false-positive results from the NIPS, 53.1 % (17/32) were found to be maternal mosaicism monosomy X. In cases with 47, XXX false-positive results, 60 % (6/10) of them were maternal 47,XXX (5 cases) or maternal mosaicism 47,XXX (1 case). One (1/6, 16.7 %) case of maternal mosaicism monosomy X was detected in the false positive results of 47, XXY/47, XYY revealed. The incidence rate of maternal sex chromosome abnormalities was positively correlated with the Z-score of ChrX. When the Z-score of ChrX ≥ 15, more than 50 % of pregnant women were found to be maternal sex chromosome abnormalities, and when Z-score ≥ 30, the incidence rate was as high as 100 %. CONCLUSIONS: Maternal monosomy X mosaicism and trisomy X respectively played an important role in the discordance of 45, X and 47, XXX revealed by NIPS. CNV-seq was recommended for the pregnant women at risk of maternal sex chromosome abnormalities, which could help clinicians to provide more accurate and efficient advice during genetic counseling and to guide appropriate prenatal diagnosis strategy for the next pregnancy.


Assuntos
Transtornos do Cromossomo Sexual no Desenvolvimento Sexual , Trissomia , Síndrome de Turner , Feminino , Humanos , Gravidez , Masculino , Trissomia/diagnóstico , Trissomia/genética , Síndrome de Turner/diagnóstico , Síndrome de Turner/genética , Mosaicismo , Variações do Número de Cópias de DNA , Estudos Retrospectivos , Aberrações dos Cromossomos Sexuais , Diagnóstico Pré-Natal/métodos , Cromossomos Humanos X/genética , Aneuploidia
20.
Genes (Basel) ; 15(1)2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38254992

RESUMO

The translocation of the testis-determining factor, the SRY gene, from the Y to the X chromosome is a rare event that causes abnormalities in gonadal development. In all cases of males and females carrying this translocation, disorder of sex development is reported. In our study, we described a peculiar pedigree with the first evidence of four healthy females from three generations who are carriers of the newly identified t(X;Y)(q28;p11.2)(SRY+) translocation with no evidence of ambiguous genitalia or other SRY-dependent alterations. Our study was a consequence of a Non-Invasive Prenatal Test (NIPT) showing a sexual chromosomal abnormality (XXY) followed by a chorionic villus analysis suggesting a normal karyotype 46,XX and t(X;Y) translocation detected by FISH. Here, we (i) demonstrated the inheritance of the translocation in the maternal lineage via karyotyping and FISH analysis; (ii) characterised the structural rearrangement via chromosomal microarray; and (iii) demonstrated, via Click-iT® EdU Imaging assay, that there was an absolute preferential inactivation of the der(X) chromosome responsible for the lack of SRY expression. Overall, our study provides valuable genetic and molecular information that may lead personal and medical decisions.


Assuntos
Cromossomos Humanos X , Genes sry , Masculino , Gravidez , Humanos , Feminino , Proteína da Região Y Determinante do Sexo/genética , Cromossomos Humanos X/genética , Aberrações Cromossômicas , Cariotipagem , Translocação Genética/genética
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