Klinefelter Syndrome Patients Research Articles

Rates of hypogonadism forms in Klinefelter patients undergoing testicular sperm extraction: A multicenter cross-sectional study.

Adult patients with Klinefelter syndrome (KS) may present with testicular volume loss and a decrease in circulating testosterone (T) levels. However, the actual rate of hypogonadism in adult KS men is unknown. We aimed to (a) assess the prevalence of different forms of hypogonadism in a cohort of KS patients with non-obstructive azoospermia (NOA); and (b) investigate potential preoperative predictor of positive sperm retrieval (SR) at surgery in the same cohort of men. Complete data from 103 KS men with NOA who underwent testicular sperm extraction (TESE) between 2008 and 2019 at five centers were analyzed. Comorbidities were scored with the Charlson Comorbidity Index (CCI). Patients were categorized into four groups of hypogonadism as follows: eugonadism [normal total T (tT) (≥3.03ng/mL) and normal luteinizing hormone (LH) (≤9.4 mUI/mL)], secondary hypogonadism [low tT (≤3.03ng/mL) and low/normal LH (≤9.4 mUI/mL)], primary hypogonadism [low tT (≤3.03ng/mL) and elevated LH (≥9.4 mUI/mL)], and compensated hypogonadism [normal tT (≥3.03ng/mL) and elevated LH (≥9.4 mUI/mL)]. Descriptive statistics tested the association between clinical characteristics and laboratory values among the four groups. Median (IQR) patients age was 32 (24, 37) years. Baseline follicle-stimulating hormone and tT levels were 29.5 (19.9, 40.9) mUI/mL and 3.8 (2.5, 11.0) ng/mL, respectively. Eugonadism, primary hypogonadism, and compensated hypogonadism were found in 16 (15.6%), 34 (33.0%), and 53 (51.4%) men, respectively. No patients had secondary hypogonadism. Positive SR rate at TESE was 21.4% (22 patients); of 22, 15 (68.2%) patients underwent assisted reproductive technology and five (22.7%) ended in live birth children. Patients' age, BMI, CCI, FSH levels, and positive SR rates were comparable among hypogonadism groups. No preoperative parameters were associated with positive SR at logistic regressions analysis. Findings from this cross-sectional study showed that 15.6% of adult KS men have normal tT values at presentation in the real-life setting. Most KS patients presented with either compensated or primary hypogonadism. Sperm retrieval rates were not associated with different forms of hypogonadism.

Testosterone treatment in male patients with Klinefelter syndrome: a systematic review and meta-analysis.

Low testosterone (T) in Klinefelter's syndrome (KS) can contribute to typical features of the syndrome such as reduced bone mineral density, obesity, metabolic disturbances and increased cardiovascular risk. The aim of the present study is to review and meta-analyze all available information regarding possible differences in metabolic and bone homeostasis profile between T treated (TRT) or untreated KS and age-matched controls. We conducted a random effect meta-analysis considering all the available data from observational or randomized controlled studies comparing TRT-treated and untreated KS and age-matched controls. Data were derived from an extensive MEDLINE, Embase, and Cochrane search. Out of 799 retrieved articles, 21 observational and 22 interventional studies were included in the study. Retrieved trials included 1144 KS subjects and 1284 healthy controls. Not-treated KS patients showed worse metabolic profiles (including higher fasting glycemia and HOMA index as well as reduced HDL-cholesterol and higher LDL-cholesterol) and body composition (higher body mass index and waist circumference) and reduced bone mineral density (BMD) when compared to age-matched controls. TRT in hypogonadal KS subjects was able to improve body composition and BMD at spinal levels but it was ineffective in ameliorating lipid and glycemic profile. Accordingly, TRT-treated KS subjects still present worse metabolic parameters when compared to age-matched controls. TRT outcomes observed in KS regarding BMD, body composition and glyco-metabolic control, are similar to those observed in male with hypogonadism not related to KS. Moreover, body composition and BMD are better in treated than untreated hypogonadal KS. Larger and longer randomized placebo-controlled trials are advisable to better confirm the present data, mainly derived from observational studies.

ART strategies in Klinefelter syndrome.

Patients with Klinefelter syndrome (KS) who receive assisted reproductive technology (ART) treatment often experience poor pregnancy rates due to decreased fertilization, cleavage, and implantation rates and even an increased miscarriage rate. Mounting evidence from recent studies has shown that various technological advances and approaches could facilitate the success of ART treatment for KS patients. In this review, we summarize the methods for guiding KS patients during ART and for developing optimal strategies for preserving fertility, improving pregnancy rate and live birth rate, and avoiding the birth of KS infants. We searched PubMed and Google Scholar publications related to KS patients on topics of controlled ovarian stimulation protocols, sperm extraction, fertility preservation, gamete artificial activation, round spermatid injection (ROSI), and non-invasive prenatal screening (PGD) methods. This review outlines the different ovulation-inducing treatments for female partners according to the individual sperm status in the KS patient. We further summarize the methods of retrieving sperm, storing, and freezing rare sperm. We reviewed different methods of gamete artificial activation and discussed the feasibility of ROSI for sterile KS patients who absolutely lack sperm. The activation of eggs in the process of intracytoplasmic sperm injection and non-invasive PGD are urgently needed to prevent the birth of KS infants. The integrated strategies will pave the way for the establishment of ART treatment approaches and improve the clinical outcome for KS patients.

Seminal plasma miRNAs in Klinefelter syndrome and in obstructive and non-obstructive azoospermia.

MicroRNAs are small, non-coding, single-strand oligonucleotides which regulate gene expression. There is little evidence in the literature about their role in azoospermia and no studies have investigated their presence in the seminal plasma of men with Klinefelter syndrome. This retrospective study investigated if there were any differences in microRNA expression (miR-509-5p, miR-122-5p, miR-34b-3p, miR-34c-5p) in the seminal plasma of patients with obstructive azoospermia, non-obstructive azoospermia and Klinefelter syndrome. Hormone levels were also investigated to identify any correlations with microRNA expression. We analysed 200 subjects (40 Klinefelter syndrome, 60 non-obstructive azoospermia with a normal karyotype, 60 obstructive azoospermia and 40 who were normozoospermic). All subjects underwent semen examination. Total RNA was obtained from seminal plasma and microRNA expression was analysed by RT-qPCR. There was a significant reduction in the expression of all investigated miRNAs in the seminal plasma of all patient categories in comparison with controls. There was a weak negative correlation between FSH values and miR-509-5p expression in non-obstructive azoospermic patients (r = -0.391; p = 0.014). We hypothesize that in non-obstructive azoospermia and Klinefelter syndrome patients, the downregulation of microRNAs may be caused by damage to the germ cells and aberrant spermatogenesis. In our opinion the identification of seminal plasma microRNAs deriving almost exclusively from the testes could be essential for the development of specific biomarkers for male infertility. The expression of such microRNAs, in combination with hormone values, could comprise testicular markers of abnormal spermatogenesis and failed mature sperm production.

Epigenetics and genomics in Klinefelter syndrome.

Since the first description of Klinefelter syndrome (KS) was published in 1942 in The Journal of Clinical Endocrinology, large inter-individual variability in the phenotypic presentation has been demonstrated. However, our understanding of the global impact of the additional X chromosome on the genome remains an enigma. Evidence from the existing literature of KS indicates that not just one single genetic mechanism can explain the phenotype and the variable expressivity, but several mechanisms may be at play concurrently. In this review, we describe different genetic mechanisms and recent advances in the understanding of the genome, epigenome, and transcriptome of KS and the link to the phenotype and clinical heterogeneity. Future studies are needed to unite clinical data, genomic data, and basic research attempting to understand the genetics behind KS. Unraveling the genetics of KS will be of clinical relevance as it may enable the use of polygenic risk scores to predict future disease susceptibility and enable clinical risk stratification of KS patients in the future.

Metabolic and cardiovascular risk factors in Klinefelter syndrome

Klinefelter syndrome (KS), which normally presents with a 47,XXY karyotype, is the most common sex chromosome disorder in males. It is also the most common genetic cause of male infertility. KS subjects are typically tall, with small and firm testes, gynecomastia, broad hips, and sparse body hair, although a less evident presentation is also possible. KS is also characterized by a high prevalence of hypogonadism, metabolic syndrome (MetS) and cardiovascular disease. The aim of this article is to systematically review metabolic and the cardiovascular risk factors in KS patients. Hypogonadism has an important role in the pathogenesis of the changes in body composition (particularly visceral obesity) and hence of insulin resistance and MetS, but the association between KS and MetS may go beyond hypogonadism alone. From childhood, KS patients may show an increase in visceral fat with a reduction in lean body mass and an increase in glucose and impaired fat metabolism. Their increased incidence of congenital anomalies, epicardial adipose tissue, and thromboembolic disease suggests they have a higher risk of cardiovascular disease. There is conflicting evidence on the effects of testosterone therapy on body composition and metabolism.

Germ cell loss in Klinefelter syndrome: When and why?

Klinefelter syndrome (KS) is a quite common disorder with an incidence of 1-2 in 1,000 new-born males. Most patients are diagnosed in the light of a clinical checkup when consulting a fertility clinic with an unfulfilled child wish. Infertility in KS patients is caused by a massive germ cell loss, leading to azoospermia in more than 90% of the adult patients. Most seminiferous tubules in the adult KS testis are degenerated or hyalinized and testicular fibrosis can be observed, starting from puberty. However, focal spermatogenesis can be found in the testis of some patients. This offers the opportunity to extract spermatozoa from the testis by testicular sperm extraction (TESE). Nevertheless, TESE is only successful in about half of the KS adults seeking to father children. The reason for the germ cell loss remains unclear. To date, it is still debated whether the testicular tissue changes and the germ cell loss seen in KS is directly caused by an altered X-linked gene expression, the altered somatic environment, or a deficiency in the germ cells. In this review, we provide an overview of the current knowledge about the germ cell loss in KS patients.

Characterization of the stem cell niche components within the seminiferous tubules in testicular biopsies of Klinefelter patients

To characterize the tubular environment in testicular biopsy tissues from patients with Klinefelter syndrome (KS). Observational immunohistochemical study. Academic research unit. Males with KS and controls at different developmental time points: fetal, prepubertal, peripubertal, and adult. Immunohistochemical analysis of testicular biopsies samples to characterize maturation of Sertoli cells and tubular wall components-peritubular myoid cells (PTMC) and extracellular matrix (ECM) proteins. Intensity of antimüllerian hormone staining; proportion of Sertoli cells expressing androgen receptor (AR); and expression of tubular wall markers as characterized by identifying abnormal staining patterns. Decreased expression for alpha smooth muscle actin 2 (ACTA2) was observed in peripubertal and adult KS as well as in Sertoli cell only (SCO) patients. Altered expression patterns for all ECM proteins were observed in SCO and KS biopsy tissues compared with controls. Only for collagen I and IV were altered expression patterns observed between KS and SCO patients. In peripubertal samples, no statistically significant differences were observed in the maturation markers, but altered ECM patterns were already present in some samples. The role of loss of ACTA2 expression in PTMC in the disintegration of tubules in KS patients should be further investigated. Future research is necessary to identify the causes of testicular fibrosis in KS patients. If the mechanism behind this fibrotic process could be identified, this process might be altered toward increasing the chances of fertility in KS patients.

MP44-04 IDENTIFYING PATHWAY DELAYS AND PATIENT NEEDS TO OPTIMIZE THE MANAGEMENT OF MEN WITH ADULT KLINFELTER SYNDROME

INTRODUCTION AND OBJECTIVE: Men with Klinefelter Syndrome (KS) often present with infertility. However, the optimal management of this condition can involve many different specialties. Unfortunately, this often results in major gaps and delays to the patient pathway, often with a lack of coordination in areas such as genetic & psychosexual counselling. Based on this, a national survey was carried out to assess the needs of adult Klinefelter Syndrome patients with the aim of setting up a one-stop multidisciplinary team (MDT) clinic model for KS. METHODS: Men with KS over age 18 who were members of the Klinefelter Association of the UK as well as current KS patients in three large teaching hospitals were invited to participate in the study. A detailed, anonymised online questionnaire was used to collect data on initial presentation, delays and gaps in management and outcomes. Separately, an expert panel involving 7 specialties (Urology, Endocrinology, Genetics, Radiology, Reproductive Medicine, Embryology, Psychosexual Medicine), patient representatives and allied specialties (pharmacy & nursing) was set up to identify the feasibility and benefits of an MDT clinic. Ethics approval was obtained from our local NHS board. RESULTS: 92 patients in total completed the online questionnaire. 65% presented with infertility. Almost half had noticed signs of KS by the age of 16 but the median age of diagnosis was 26-30 with more than 20% diagnosed after 35. 45% waited a year or more in primary care before eventually being referred to a urologist, with definitive fertility management starting 1-2 years after. Only 39% had formal genetic counselling, and 35% had no long-term endocrine input. Although 87% were aware of surgical sperm retrieval, only 30% were offered MicroTESE. 89% felt they would have benefited from seeing an endocrinologist (and 61% for psychology) at diagnosis, with 86% strongly supporting an MDT clinic approach. The MDT clinic would also decrease visits, ensure a standard of care and potentially reduce delays to definitive fertility management from 18 to 3 months. CONCLUSIONS: The valuable information gathered about the delays and issues faced by adult men with Klinefelter Syndrome have led to the setting up of a one-stop MDT clinic encompassing 7 specialties with pharmacy & patient liaison services. The clinic itself and its positive clinician and patient feedback are presented separately. The need for more awareness of KS in the community remains a widespread issue. Source of Funding: None

Detection of low-grade mosaicism and its correlation with hormonal profile, testicular volume, and semen quality in a cohort of Egyptian Klinefelter and Klinefelter-like patients

Klinefelter syndrome (KS) is the most common chromosomal syndrome, causing infertility in men and leading to non-obstructive azoospermia. Previous studies on mosaicism have shown contradictory results on its correlation with both serum hormone levels and the presence of spermatozoa in the ejaculate of KS, KS-like, and non-KS-like infertile patients. So, the present study was designed to detect low-grade mosaicism in the peripheral blood lymphocytes and buccal mucosa cells of 14 KS and 8 KS-like patients by using fluorescence in situ hybridization (FISH) and to investigate its correlation with luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T) levels, testicular volume, and semen analysis compared with 10 normal healthy fertile men. Our results indicated that mosaicism was only found in 42.9 % of the KS patients and completely absent in all KS-like patients. Moreover, mosaicism has led to complete azoospermia and non-significant differences in both hormone levels and testicular volume between mosaic and non-mosaic KS patients. All KS patients demonstrated significant differences in both hormone levels and testicular volume compared with normal men. Conversely, they revealed non-significant differences in hormone levels and significant differences in testicular volume compared with KS-like patients. Additionally, the KS-like patients exhibited non-significant variations in both LH and FSH levels and significant variations in T level and testicular volume compared with normal men. Moreover, all KS-like patients had azoospermia, except for one patient who showed oligozoospermia. Therefore, no correlations were found either between mosaicism and serum hormone levels or with testicular volume and semen analysis.

Sperm retrieval rates in non-mosaic Klinefelter patients undergoing testicular sperm extraction: What expectations do we have in the real-life setting?

A recent meta-analysis (Human Reproduction Update 23, 2017 and 265) reported positive sperm retrieval rates (SRR) in 50% of patients with Klinefelter syndrome (KS) undergoing testicular sperm extraction (TESE). However, these results do not reflect the rates of SR that we observe in clinical practice. We assessed the rate and potential predictors of SR in Klinefelter patients in the real-life setting. We reviewed clinical data of 103 KS men who underwent TESE between 08/2008 and 03/2019 at five tertiary referral Andrology centers. Patients underwent testis ultrasound, hormonal evaluation, and genetic testing. All patients were azoospermic based on the 2010 WHO reference criteria. Conventional TESE (cTESE) or microsurgical TESE (mTESE) was performed based on the surgeon's preference. We used descriptive statistics and logistic regression models to describe the whole cohort. Median (IQR) patient's age was 32 (24-37) years. Baseline serum FSH and total testosterone levels were 29.5 (19.9-40.9) mUI/mL and 3.8 (2.5-11.0) ng/mL, respectively. Conventional TESE and mTESE were performed in 38 (36.5%) and 65 (63.5%) men, respectively. The sperm retrieval rate was 21.4% (22/103 men). Fifteen patients used spermatozoa for ICSI and five ended in live birth children. Patients with positive SR were similar to those with a negative TESE in terms of clinical, hormonal, and procedural parameters (all P>.05). Logistic regression analyses confirmed the lack of association between clinical, hormonal, and procedural parameters with SR outcome. Given the conflicting results in the literature regarding SRR in KS, patients should be carefully counseled regarding TESE outcomes based on data from published literature and local results. In the real-life setting, we observed a lower SRR (21.4%) than that reported in meta-analyses in our cohort of KS patients. No associations between clinical, hormonal, and procedural variables with TESE success were found.

Cytogenetic findings in Serbian patients with Klinefelter syndrome

Klinefelter syndrome (KS) describes the phenotype of the most common sex chromosome abnormality in humans (1/600 newborn males). The most widespread karyotype in affected patients is 47,XXY, but various others have been described. The aim of this study was to examine the karyotypes of a group of patients suspected of having Klinefelter's syndrome. Between January 1993 and April 2018 104 adult KS patients were evaluated. Cytogenetic analysis was carried out on metaphases obtained from phytohemagglutinin-stimulated peripheral lymphocytes using a standard procedure. Fluorescence in situ hybridization (FISH) analysis was performed on peripheral blood specimens. Vysis CEP X/Y- alpha satellite DNA probes were used to detect X and Y chromosomes. We identified KS presenting the ?standard? or 47,XXY karyotype in eighty three (80%) patients, while five (5%) KS patients showed the mosaic karyotype 47,XXY/46,XY and three (3%) patients had the mosaic karyotype 47,XXY/46,XX. In six (6%) cases KS patients with the ?standard? karyotype also had autosomal chromosomal abnormalities, while numerical sex chromosome abnormalities, with karyotypes 48,XXYY occurred in two (2%) subjects, 47,XYY in three (3%) and 47,XYY/46,XY in two (2%) individuals. Thus, most of our KS patients had the 'standard', 47,XXY karyotype, but some men formed a group of patients with a diversity of other karyotypes. These disparate chromosomal variants may have different physical and mental implications for the general symptomatology of KS. Therefore, it is important to determine the nature of the karyotype of every male with clinical characteristics of KS in very early childhood in order to initiate an adequate, personalized, medical approach.

High frequency of Klinefelter syndrome in a cohort of Sri Lankan males with non-obstructive azoospermia and oligozoospermia

Introduction: Klinefelter syndrome (KS) is the most common sex chromosomal aneuploidy. It affects 1:667 males. It is a major cause of male factor infertility due to the associated testicular atrophy. This study aims to describe the karyotype pattern identified in a cohort of Sri Lankan infertile males referred for cytogenetic testing prior to undergoing testicular biopsy. Materials and methods: The karyotype reports of males with severe oligozoospermia (sperm cell count<5×106 cells/ml in seminal fluid analysis) and non-obstructive azoospermia, who were referred for karyotyping between January 2010 and February 2019 were maintained prospectively in an anonymized database and analysed retrospectively. All patients were referred from a single urological practice prior to undergoing testicular biopsy. Karyotyping was performed on routinely cultured lymphocytes after GTG-banding according to the guidelines of the International System for Human Cytogenetic Nomenclature (2016). Results: A total of 69 infertile males underwent karyotyping. 40 (58.0%) had azoospermia and 29 (42.0%) had severe oligozoospermia. Abnormal karyotypes were seen in 14 (20.3%) males, comprising of 11 (78.6%) with KS (47,XXY) and 3 (21.4%) with 46,XX karyotype. Polymerase chain reaction for SRY gene was positive in one male with 46,XX karyotype. Among the KS patients, 6 (54.6%) had azoospermia and 5 (45.5%) had severe oligozoospermia. Conclusions: KS accounted for more than two-thirds of the chromosomal anomalies among the infertile males referred for karyotyping. These findings highlight the need for cytogenetic evaluation of severe oligozoospermic and azoospermic males prior to undertaking extensive invasive investigations and treatment measures in both partners.

Spermatological characteristics of mosaic and non-mosaic forms of Klinefelter syndrome

The study objectiveis to compare of ejaculate parameters in mosaic, non-mosaic Klinefelter syndrome (KS).Materials and methods. Eighty-five patients with KS were examined. The group 1 included 75 patients between the ages of 17 and 39 with non-mosaic KS (47,XXY), the group 2 included 10 males between the ages of 22 and 57 years with mosaic KS: 47,XXY/46,XY (n = 9), 48,XXY,der(X)/47,XXY/46,XY (n = 1).Results. KS patients semen volume was 1.9 ± 1.3 (0.1–5.5) ml in non-mosaic KS patients (47,XXY) and 1.5 ± 1.2 (0.05–4.00) ml in patients with a mosaic form of a KS, respectively, рН semen – 7.8 ± 0.5 (6.5–9.0) and 7.8 ± 0.2 (7.5–8.1), sperm count – 0.27 ± 1.42 (0.00–12.50) and 0.12 ± 0.28 (0.00–0.90) million/ml, respectively. The viscosity was increased (&gt;20 mm) at 41 % non-mosaic KS (group 1) and 22 % of mosaic KS (group 2) patients. The ejaculate sediment was investigated by quantitative karyological analysis of immature germ cells. The germ cells in 42 % samples of the ejaculate of the patients with a classical form of a KS and in 20 % samples of the ejaculate of the patients with a mosaic form was found. That indicates a partial preservation of spermatogenesis.Conclusion. The degree of spermatogenesis depletion in KS patients widely varied, ejaculate and germ cell parameters in the ejaculate sediment weren’t significantly different. Presence of few sperms (cryptozoospermia) and immature cells in the ejaculate sediment point to partial preservation of spermatogenesis.

A Case Report of Exacerbation of Leg Ulcers Associated with Acute High-dose Acetylsalicylic Acid in a Patient with Klinefelter Syndrome

Klinefelter syndrome (KS) is the most frequent type of congenital sex-chromosomal disorder caused by at least one extra X chromosome and commonly treated with lifetime testosterone therapy. Ulcerative lesions on lower extremities may occur as a complication of KS. The pathogenesis of ulcers in KS patients has not been clarified on a molecular level. Here we present a case of leg ulcers exacerbation associated with the administration of a high dose of acetylsalicylic acid in a 63-year-old KS patient with karyotype 47,XXY undergoing testosterone replacement therapy for the last 20 years. The appearance of the ulcer on the patient's leg occurred during one week of high oral acetylsalicylic acid intake (1.2 g daily). The patient was advised to return to his standard daily dose of 0.1 g of acetylsalicylic acid and significant improvement of his leg ulcer was observed after two weeks. We hypothesize that testosterone-mediated nitric oxide balance in KS patient is perturbed under the condition of acute high-dose acetylsalicylic acid administration. We propose that small standard doses of approximately 0.1 g/day of acetylsalicylic acid have no apparent effect on nitric oxide status, whereas higher doses may cause dysregulation of nitric oxide production and/or utilization, creating conditions which may cause the appearance of leg ulcers in the KS patients.

Blood Testis Barrier and Somatic Cells Impairment in a Series of 35 Adult Klinefelter Syndrome Patients.

Klinefelter Syndrome (KS) is the most common genetic cause of infertility in men. Degeneration of the testicular tissue starts in utero and accelerates at puberty with hyalinisation of seminiferous tubules, spermatogonia apoptosis and germ cell maturation arrest. Therefore, fertility preservation in young KS boys has been proposed, although this measure is still debated due to insufficient knowledge of the pathophysiology of the disease. To better understand the underlying mechanisms of testicular failure and germ cell loss, we analysed functional and morphological alterations in the somatic compartment of KS testis, i.e., Sertoli cells, including the blood–testis barrier (BTB) and Leydig cells (LC). We compared three populations: 35 KS 47,XXY non-mosaic patients, 28 Sertoli-cell-only (SCO) syndrome patients and 9 patients with normal spermatogenesis. In KS patients the expression of BTB proteins connexin-43 and claudin-11 assessed with a semi-quantitative scoring system appeared significantly reduced with a disorganised pattern. A significant reduction in seminiferous tubules expressing androgen receptors (AR) was observed in KS compared to normal spermatogenesis controls. INSL3 expression, a marker of LC maturation, was also significantly reduced in KS compared to patients with normal spermatogenesis or SCO. Hence, the somatic compartment impairment in KS could be involved in degeneration of seminiferous tubules.

Human induced pluripotent stem cells from two azoospermic patients with Klinefelter syndrome show similar X chromosome inactivation behavior to female pluripotent stem cells.

STUDY QUESTIONDoes the X chromosome inactivation (XCI) of Klinefelter syndrome (KS)-derived human induced pluripotent stem cells (hiPSCs) correspond to female human pluripotent stem cells (hPSCs) and reflect the KS genotype?SUMMARY ANSWEROur results demonstrate for the first time that KS-derived hiPSCs show similar XCI behavior to female hPSCs in culture and show biological relevance to KS genotype-related clinical features.WHAT IS KNOWN ALREADYSo far, assessment of XCI of KS-derived hiPSCs was based on H3K27me3 staining and X-inactive specific transcript gene expression disregarding the at least three XCI states (XaXi with XIST coating, XaXi lacking XIST coating, and XaXe (partially eroded XCI)) that female hPSCs display in culture.STUDY DESIGN, SIZE, DURATIONThe study used hiPSC lines generated from two azoospermic patients with KS and included two healthy male (HM) and one healthy female donor.PARTICIPANTS/MATERIALS, SETTING, METHODSIn this study, we derived hiPSCs by reprograming fibroblasts with episomal plasmids and applying laminin 521 as culture substrate. hiPSCs were characterized by karyotyping, immunocytochemistry, immunohistochemistry, quantitative PCR, teratoma formation, and embryoid body differentiation. XCI and KS hiPSC relevance were assessed by whole genome transcriptomics analysis and immunocytochemistry plus FISH of KS, HM and female fibroblast, and their hiPSC derivatives.MAIN RESULTS AND THE ROLE OF CHANCEApplying whole genome transcriptomics analysis, we could identify differentially expressed genes (DEGs) between KS and HM donors with enrichment in gene ontology terms associated with fertility, cardiovascular development, ossification, and brain development, all associated with KS genotype-related clinical features. Furthermore, XCI analysis based on transcriptomics data, RNA FISH, and H3K27me3 staining revealed variable XCI states of KS hiPSCs similar to female hiPSCs, showing either normal (XaXi) or eroded (XaXe) XCI. KS hiPSCs with normal XCI showed nevertheless upregulated X-linked genes involved in nervous system development as well as synaptic transmission, supporting the potential use of KS-derived hiPSCs as an in vitro model for KS.LIMITATIONS, REASONS FOR CAUTIONDetailed clinical information for patients included in this study was not available. Although a correlation between DEGs and the KS genotype could be observed, the biological relevance of these cells has to be confirmed with further experiments. In addition, karyotype analysis for two hiPSC lines was performed at passage 12 but not repeated at a later passage. Nevertheless, since all XCI experiments for those lines were performed between passage 11 and 15 the authors expect no karyotypic changes for those experiments.WIDER IMPLICATIONS OF THE FINDINGSAs KS patients have variable clinical phenotypes that are influenced by the grade of aneuploidy, mosaicism, origin of the X chromosome, and XCI ‘escapee’ genes, which vary not only among individuals but also among different tissues within the same individual, differentiated KS hiPSCs could be used for a better understanding of KS pathogenesis.STUDY FUNDING/COMPETING INTEREST(S)This study was supported by grants from the Knut and Alice Wallenberg Foundation (2016.0121 and 2015.0096), Ming Wai Lau Centre for Reparative Medicine (2-343/2016), Ragnar Söderberg Foundation (M67/13), Swedish Research Council (2013-32485-100360-69), the Centre for Innovative Medicine (2–388/2016–40), Kronprinsessan Lovisas Förening För Barnasjukvård/Stiftelsen Axel Tielmans Minnesfond, Samariten Foundation, Jonasson Center at the Royal Institute of Technology, Sweden, and Initial Training Network Marie Curie Program ‘Growsperm’ (EU-FP7-PEOPLE-2013-ITN 603568). The authors declare no conflicts of interest.

Single-Cell Sequencing Reveals the Relationship between Phenotypes and Genotypes of Klinefelter Syndrome

Klinefelter syndrome (KS) is one of the most common congenital disorders of male infertility. Given its high heterogeneity in clinical and genetic presentation, the relationship between transcriptome, clinical phenotype, and associated co-morbidities seen in KS has not been fully clarified. Here, we report a 47,XXY Chinese male with infertility and analyzed the differences in gene expression patterns of peripheral blood mononuclear cells (PBMCs) with regard to a Chinese male and a female control with normal karyotype by single-cell sequencing. A total of 24,439 cells were analyzed and divided into 5 immune cell types (including B cells, T cells, macrophage cells, dendritic cells, and natural killer cells) according to marker genes. Using unsupervised dimensionality reduction and clustering algorithms, we identified molecularly distinct subpopulations of cells between the KS patient and both controls. Gene ontology enrichment analyses yielded terms associated with well-known comorbidities seen in KS as well as an affected immune system and type I diabetes mellitus. Based on our data, we identified several candidate genes which may be implicated in regulating the phenotype of KS. Overall, this analysis provides a comprehensive map of the cell types of PBMCs in a KS patient at the single-cell level, which will contribute to the prevention of comorbidity and improvement of the life quality of KS patients.

Relationship between testicular histopathology and the success of testicular sperm extraction in patients with non-mosaic Klinefelter syndrome

ObjectiveTo investigate the effect of testicular histopathology on the success of microscopic testicular sperm extraction (mTESE) and the factors that could predict the success of mTESE in patients with non-mosaic Klinefelter syndrome (KS). Material and methodsForty-one KS patients diagnosed with non-obstructive azoospermia (NOA) who had undergone mTESE at our clinic were included in the study. The patients were divided into 5 groups according to the histopathology results: hyalinisation of tubules (HT), sertoli cell only (SCO), early maturation arrest (EMA), late maturation arrest (LMA), and hypospermatogenesis (HS). The groups were compared with regard to age, duration of infertility, hormone profile, testicular volume, and sperm retriveal rate. The clinical features of the patients with mTESE from whom sperm could or could not be obtained were also compared with the aim of investigating the predictive value of testicular histopathology and the other variables for prediction of the success of mTESE. ResultsSperm could be obtained through mTESE in 13 out of 41 patients (31.7%). A statistically significant difference was determined between the groups with regard to the rate of sperm collection. No significant difference was determined between the histopathology groups with regard to the other variables. A statistically significant difference was determined between the groups from whic sperm could be collected or not with regard to age, Johnsen criteria, SCO, EMA and LMA variables. Multi-variate analysis revealed that age and Johnsen score were the independent variables predictive for success of mTESE. ConclusionThe present study has revealed that impairment in testicular histopathology negatively affects the success of mTESE and that it is a predictive factor for the success of mTESE in patients with KS. Increased patient age was also determined to negatively affect the success of mTESE and the operation was demonstrated to be more successful before 34 years of age.

Where does extra X in klinefelter syndrome come from?

It has been reported that the incidence of sperms with disomic XY is higher in the testis tissue smear of KS patients and these sperms are the cause of KS. However some papers report the maternal origin. So we performed this study to investigate the origin of extra X in Klinefelter Syndrome (KS). Cytogenetic analysis in KS patients and their parents. Blood samples from 29 KS patients were used for X-chromosome short tandem repeats (STR) analysis. The STR analysis also included data of the parents of the KS patients (24: both parents, 5: mother only, 0: father only) from January 2015 to March 2019. This study was conducted with the informed consent of all participating patients and approved by The Institutional Review Boards of the Saint Mother Obstetrics and Gynecology Clinic and adhered to JCMJER criteria UMIN Clinical Trial Registry was UMIN000024542. Blood samples of 29 KS patients and one or both of their parents were used to determine the origin of the extra X chromosome using X-chromosome haplotype markers (short tandem repeats of 12 loci), according to the method by Shrivastava et al. With DNA extracted from the samples, multiplexed PCR amplifications of the 12 X-STR loci and AMELOGENIN were conducted using an Investigator Argus X-12 QS Kit (Quigen, Germany). The data obtained was analyzed with GeneMapper ID software. X-chromosomal STR DNA profiles were compared among KS patient and their parents. In 13 of the 29 KS patients, both two X chromosomes were maternal origin, showing that an extra X chromosome was left in an oocyte as a result of chromosomal non-disjunction at the 1st (4/13) or 2nd (9/13) meiotic division. In 15 patients, X-chromosomes were inherited from parents, suggesting that fertilization of XY-sperm is the cause of KS.Table 1The result of X-chromosome STR analysis (a case of maternal origin extra-X)Patient no. 09KYMarkerDXS10148DXS10135DXS8378DXS10079DXS10074DXS7132Father20221018, 211716Mother20, 22.121, 221017, 18, 2016, 1814, 15Patient22.1221018, 201814MarkerHPRTBDXS10101DXS10103DXS10134DXS10146DXS7423Father1231.2183524, 40.214Mother13, 1429, 31.217, 1936, 37.326, 3215, 16Patient1429, 31.217, 1936, 37.326, 3215, 16 Open table in a new tab Although the sample number applied for X-chromosomal STR DNA profiling is not enough, the present data may indicate that contribution of XX oocyte to the production of XXY embryos is greater than XY sperm. Namely, a XX oocyte penetration by a Y sperm is the main cause of KS. Cytogenetic analysis with smear of testicular cell mixture that was used in the studies may overestimate chromosomal abnormality.