Non-organ-specific autoimmunity in adult 47,XXY Klinefelter patients and higher-grade X-chromosome aneuploidies.

Current literature regarding systemic autoimmune diseases in X-chromosome aneuploidies is scarce and limited to case reports. Our aim was to evaluate the frequency of anti-nuclear (ANAs), extractable nuclear (ENA), anti-double-stranded DNA (dsDNAs), anti-smooth muscle (ASMAs) and anti-mitochondrial (AMAs) antibodies in a large cohort of adults with Klinefelter's syndrome (KS, 47,XXY) and rare higher-grade sex chromosome aneuploidies (HGAs) for the first time. Sera from 138 X-chromosome aneuploid patients [124 adult patients with 47,XXY KS and 14 patients with HGA (six children, eight adults)] and 50 age-matched 46,XY controls were recruited from the Sapienza University of Rome (2007-17) and tested for ANAs, ENAs, anti-dsDNAs, ASMAs and AMAs. Non-organ-specific immunoreactivity was found to be significantly higher in patients with 47,XXY KS (14%) than in the controls (2%, p = 0.002). Among all the antibodies investigated, only ANAs were observed significantly more frequently in patients with 47,XXY KS (12.1%) than in the controls (2%, p = 0.004). No anti-dsDNA immunoreactivity was found. Stratifying by testosterone replacement therapy (TRT), non-organ-specific autoantibody frequencies were higher in TRT-naive (p = 0.01) and TRT-treated groups than in controls. No patients with HGA were found positive for the various autoantibodies. Non-organ-specific autoantibodies were significantly present in 47,XXY adult patients. Conversely, HGAs did not appear to be target of non-organ-specific immunoreactivity, suggesting that KS and HGAs should be considered as two distinct conditions. The classification and diagnosis of systemic autoimmune diseases is frequently difficult. To support a correct clinical evaluation of KS disease and to prevent eventual secondary irreversible immune-mediated damages, we highlight the importance of screening for non-organ-specific autoimmunity in Klinefelter's syndrome.

Epigenetic and transcriptomic consequences of excess X-chromosome material in 47,XXX syndrome-A comparison with Turner syndrome and 46,XX females.

47,XXX (triple X) and Turner syndrome (45,X) are sex chromosomal abnormalities with detrimental effects on health with increased mortality and morbidity. In karyotypical normal females, X-chromosome inactivation balances gene expression between sexes and upregulation of the X chromosome in both sexes maintain stoichiometry with the autosomes. In 47,XXX and Turner syndrome a gene dosage imbalance may ensue from increased or decreased expression from the genes that escape X inactivation, as well as from incomplete X chromosome inactivation in 47,XXX. We aim to study genome-wide DNA-methylation and RNA-expression changes can explain phenotypic traits in 47,XXX syndrome. We compare DNA-methylation and RNA-expression data derived from white blood cells of seven women with 47,XXX syndrome, with data from seven female controls, as well as with seven women with Turner syndrome (45,X). To address these questions, we explored genome-wide DNA-methylation and transcriptome data in blood from seven females with 47,XXX syndrome, seven females with Turner syndrome, and seven karyotypically normal females (46,XX). Based on promoter methylation, we describe a demethylation of six X-chromosomal genes (AMOT, HTR2C, IL1RAPL2, STAG2, TCEANC, ZNF673), increased methylation for GEMIN8, and four differentially methylated autosomal regions related to four genes (SPEG, MUC4, SP6, and ZNF492). We illustrate how these changes seem compensated at the transcriptome level although several genes show differential exon usage. In conclusion, our results suggest an impact of the supernumerary X chromosome in 47,XXX syndrome on the methylation status of selected genes despite an overall comparable expression profile.

Generation of iPSC Cell Lines from Patients with Sex Chromosome Aneuploidies.

Somatic cell reprogramming allows the generation of human induced pluripotent stem cells (iPSCs) from patient's cells. The derived iPSCs provide an unlimited source of patient-specific cells that can be virtually differentiated in any cell of the human body. The generation of iPSCs has important implications for all human medicine fields, as they can be used for drug discovery, regenerative medicine, and developmental studies. Klinefelter Syndrome (KS) is the most common chromosome aneuploidy in males. KS is typically characterized by a 47,XXY karyotype, representing 80-90% of KS patients. In rare cases, high-grade sex chromosome aneuploidies (SCAs), 48,XXXY; 48,XXYY; 49,XXXXY, are also observed in males. Since the advent of the reprogramming technique, a few KS-iPSCs have been described. Here, we detail the methodology for generating primary fibroblasts from patients' skin biopsies and the subsequent derivation of iPSCs using an efficient integrative-free mRNA-based somatic reprogramming approach.

A mathematical framework for genetic relatedness analysis involving X chromosome aneuploidies.

The unique features of the X chromosome can be crucial to complement autosomal profiling or to disentangle complex kinship problems, providing in some cases a similar or even greater power than autosomes in paternity/maternity investigations. While theoretical and informatics approaches for pairwise X-linked kinship analyses are well established for euploid individuals, these are still lacking for individuals with an X chromosome aneuploidy. To trigger the fulfilment of this gap, this research presents a mathematical framework that enables the quantification of DNA evidence in pairwise kinship analyses, involving two non-inbred individuals, one of whom with a non-mosaic X chromosome aneuploidy: Trisomy X (47, XXX), Klinefelter (47, XXY) or Turner (45, X0) syndrome. As previously developed for a regular number of chromosomes, this approach relies on the probability of related individuals sharing identical-by-descent (IBD) alleles at one specific locus and it can be applied to any set of independently transmitted markers, with no gametic association in the population. The kinship hypotheses mostly considered in forensic casework are specifically addressed in this work, but the reasoning and procedure can be applied to virtually any pairwise kinship problem under the referred assumptions. Algebraic formulae for joint genotypic probabilities cover all the possible genotypic configurations and pedigrees. Compared with the analyses assuming individuals with a regular number of chromosomes, complicating factors rely on the different possibilities for both the parental origin of the error (either maternal or paternal), and the type of error occurred (either meiotic or post-zygotic mitotic). These imply that a non-inbred female with Triple X or a male with Klinefelter syndrome may carry two IBD alleles at the same locus. Thus, and contrarily to what occurs for the standard case, IBD partitions depend not only on the kinship hypothesis under analysis but also on the genotypic configuration of the analyzed individuals. For some cases, parameters of interest can be inferred, while for others recommended values based on the available literature are provided. This work is the starting point to analyze X-chromosomal data under the scope of kinship problems, involving individuals with aneuploidies, as it will enhance the quantification of the DNA evidence not only in forensics but also in the medical genetics field. We hope it will trigger the development of approaches including other complicating factors, as a greater number of individuals, possibility of the occurrence of mutations and/or silent alleles, as well as the analysis of linked markers.