Age, Sperm Retrieval, and Testicular Histology in Klinefelter Syndrome.

PURPOSE: We sought to examine sperm retrieval and testicular histology in males of different ages with Klinefelter syndrome. MATERIALS AND METHODS: We identified all males with Klinefelter syndrome who underwent microdissection testicular sperm extraction at our institution from 1995 to 2020. Patients were divided into adolescent (<20 years) and adult (≥20 years) cohorts. Histology and sperm retrieval were compared using chi-square statistics. Multivariable logistic regression models were used to examine factors associated with successful sperm retrieval. RESULTS: We identified 217 males with Klinefelter syndrome, of whom 59 were adolescents and 158 were adults. Adults were stratified into 10-year groupings (20-29 years, n = 62; 30-39 years, n = 88; ≥40 years, n = 8). Approximately 17% of adolescents had testis histology containing germ cells compared with 15% of the 20 to 29-year cohort, 14% of the 30 to 39-year cohort, and 0% over 40 years. In comparison to adolescents (53%), the sperm retrieval rate was significantly higher in the 20 to 29-year cohort (71%, P = .04) and lower in the ≥40-year cohort (13%, P = .03). In multivariable analysis, the presence of hypospermatogenesis on testis biopsy (OR 5.8, P = .03) was associated with higher odds of successful sperm retrieval. CONCLUSIONS: Younger males more frequently had germ cell-containing testis histology, however this finding was not associated with a higher odds of sperm retrieval. Reproductive urologists should counsel azoospermic males with Klinefelter syndrome that sperm retrieval during adolescence for fertility preservation is not required and can be performed in young adulthood.

A rare case of adult-onset spastic paraparesis associated with Klinefelter syndrome.

REPORT: The rare association of Klinefelter syndrome and the clinical presentation of a late onset chronic progressive spastic paresis. CLINICAL PRESENTATION AND GENETICS: An infertile, 61-year-old man, presented with late adult onset of gait problems, deep muscle pain, and bladder problems. He presented for the first time, years after onset with a spastic paraparesis with high arched feet. His parents had already died, but the patient described high arched feet with his mother. There is no further certain information about the parents. After thorough investigation, an additional X chromosome was found, whereafter the diagnosis of Klinefelter syndrome could be made. Other acquired and genetic causes for spastic paraparesis or hereditary motor neuropathy are excluded. CONCLUSION: This rare case, together with three other literature reports by Sasaki (Intern Med 58(3):437-440, 2019), Sajra (Med Arh 61(1):52-53, 2007) and Matsubara et al., (J Neurol Neurosurg Psychiatry 57(5):640-642, 1994). suggests that Klinefelter syndrome can be associated with spastic paraparesis, besides the other various neuropsychiatric symptoms that are more commonly described.

Mediastinal Germ-cell Tumors Relapse in a Male With Klinefelter Syndrome. Is Longer Surveillance Needed?

Germ cell tumors (GCTs) are a heterogeneous group of pediatric cancers. In up to one-third of male patients, a primary mediastinal location is associated with the presence of Klinefelter syndrome (KS). We describe a case of mediastinal GCT in a patient, with unacknowledged KS, that presented a relapse 7 years from diagnosis, that is, 2 years after the end of the follow-up program usually recommended for patients with GCT. There are no recommendations for screening for KS in patients with mediastinal GCT and there are no specific guidelines for surveillance of GCT in KS patients. Our experience suggests that KS should be suspected in patients with mediastinal GCT, and a longer follow-up plan should be implemented when GCT occurs in patients with KS.

An Unexpected Finding of Klinefelter Syndrome during Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD) Genetic Analysis.

BACKGROUND: Klinefelter syndrome is a common sex chromosome abnormality in males, characterized by an extra X chromosome compared to normal males. Glucose-6-phosphate dehydrogenase deficiency (G6PD) is an X-linked incomplete dominant defect disorder. In this study, we reported the unexpected detection of Klinefelter syndrome in a patient with G6PD. METHODS: G6PD enzyme activity was measured by immunoenzyme assay, and genetic analysis was performed using a fluorescent PCR melting curve method (PCR-melting curve). Sex chromosome number abnormalities were detected by multiplex ligation-dependent probe amplification (MLPA). The patient also underwent peripheral blood chromosome karyotype analysis. RESULTS: The patient's G6PD and 6PGD enzyme activities were 21.34 U/L and 22.85 U/L, respectively, and their ratio was below the reference range (0.93). The PCR-melting curve displayed a c.1388 heterozygous mutation in this boy, and the Sanger sequencing provided the same results. MLPA results suggested the presence of approxi-mately two copies of the X-chromosome in the boy. Finally, chromosome karyotype analysis confirmed that the boy had Klinefelter syndrome with a karyotype of 47, XXY. CONCLUSIONS: Klinefelter syndrome was accidentally detected during G6PD genetic analysis in a male. X-chromosomes can interfere with the results of G6PD genetic analysis and should be noted.

Gilles de la Tourette syndrome as a rare co-morbidity of Klinefelter syndrome.

BACKGROUND: Klinefelter syndrome (47, XXY) is the most common sex chromosome aneuploidy. In addition to male hypergonadotropic hypogonadism, a wide range of neurodevelopmental disorders, anxiety and affective symptoms have been reported in a substantial proportion of cases. CASE DESCRIPTION: We document the rare case of a 43-year-old man diagnosed with Klinefelter syndrome and co-morbid Gilles de la Tourette syndrome. He presented with multiple motor and vocal tics since adolescence, as well as anxiety and affective symptoms as his main tic-exacerbating factors. Tic severity was rated as marked (Yale Global Tic Severity Scale score of 78/100), and recommendations for the treatment of both tics and psychiatric co-morbidities were formulated. DISCUSSION: Neurodevelopmental tics in the context of Klinefelter syndrome have been previously documented in three cases only. Gilles de la Tourette syndrome is 3-4 times more common in males than females and its etiological factors include multiple genetic components (genetic heterogeneity). Our case report widens the spectrum of neurodevelopmental disorders observed in the context of Klinefelter syndrome and contributes to genetic research on the role of the X chromosome in the pathophysiology of tic disorders.

Communication of the diagnosis to Klinefelter subjects: an observational study on a key moment of the patient's life.

PURPOSE: Klinefelter syndrome (KS) is the most prevalent sex chromosome disorder among males. The communication of the KS diagnosis holds significant implications for the diagnosis's acceptance. Recently, the increased use of prenatal diagnostic procedures has raised the question of whether, when, and by whom information, once provided to parents, should be communicated to their children/adolescents. Currently, there is limited information on this topic. This study aims to investigate the most suitable timing, content, and healthcare professionals (HCPs) according to KS patients' suggestions for conveying the diagnosis, analyzing the impact of communicating the KS diagnosis on patients and their reception of the communication in real-life situations. Furthermore, research entails a comparison of the actual communication and the patients' preferred mode of communication. METHODS: Self-reported interview data was collected from 196 adults diagnosed with KS. The interview was structured, consisting of 32 multiple-choice questions covering various areas related to diagnosis communication. RESULTS: Most patients with Klinefelter syndrome reported that earlier communication would have been beneficial. Communication before the age of 18 and by parents increased the likelihood of overcoming negative consequences and relying on psychological support. CONCLUSION: To mitigate the adverse effects of poorly timed and inadequately delivered communication, typically by a single person, it is advisable that such communication be carried out at the onset of adolescence by an interdisciplinary team of HCPs (including psychologists, geneticists, endocrinologists) and parents. The information provided should not solely concentrate on hormonal and fertility aspects, but also consider other factors such as psychological variables.

A case of 49,XXXYY followed-up from infancy to adulthood with review of literature.

49,XXXYY is an extremely rare sex chromosomal aneuploidy (SCA), with only seven cases reported worldwide to date. Among these cases, only three have been documented into adulthood. Moreover, no cases of 49,XXXYY have been reported in Japan. This SCA has been identified in two scenarios: in vitro fertilization and abortion. Similar to 47,XXY, this aneuploidy is a type of Klinefelter syndrome. Aneuploidy of the X chromosome can lead to various progressive complications due to excess X chromosomes. Herein, we present the case of a Japanese man with 49,XXXYY. He exhibited developmental delays and external genitalia abnormalities since early infancy but was not closely monitored for these symptoms until the age of 3 years old. At that time, a chromosome test revealed his karyotype to be 49,XXXYY. Subsequent examinations were conducted due to various symptoms, including delayed motor development, intellectual disability, facial dysmorphisms, forearm deformities, hip dysplasia, cryptorchidism, micropenis, primary hypogonadism, and essential tremor. Since reaching puberty, he has undergone testosterone replacement therapy for primary hypogonadism, experiencing no complications related to androgen deficiency to date. He has maintained normal lipid and glucose metabolism, as well as bone density, for a prolonged period. There are no other reports on the long-term effects of testosterone treatment for the SCA. Appropriate testosterone replacement therapy is recommended for individuals with 49,XXXYY to prevent complications. This report will contribute to an enhanced understanding of the 49,XXXYY phenotype, aiding in the diagnosis, treatment, and genetic counseling of future cases.

Macular hypoplasia and high myopia in 48, xxyy syndrome: a unique case of 48, xxyy syndrome that presents with high myopia and macular dysplasia.

BACKGROUND: Among sex chromosome aneuploidies, 48, XXYY syndrome is a rare variant. This condition is marked by the existence of an additional X and Y chromosome in males, leading to a diverse range of physical, neurocognitive, behavioral, and psychological manifestations. Typical characteristics include a tall stature and infertility. Other phenotypes include congenital heart defects, skeletal anomalies, tremors, obesity, as well as the potential for type 2 diabetes and/or peripheral vascular disease. CASE PRESENTATION: A 6-year-old boy, who had been experiencing progressive vision deterioration in both eyes for the past two years, presented with a history of poor vision, delayed motor skills. The patient was diagnosed with micropenis in the pediatric outpatient clinic. Sparse hair, an unusually tall stature and craniofacial dysmorphology characterized by ocular hypertelorism, depressed nasal bridge, and epicanthic folds were observed. Comprehensive ophthalmic examination revealed high myopia and grade 3 macular hypoplasia. Diagnostic investigations including karyotype analysis and whole-exome sequencing identified an anomalous male karyotype comprising two X and two Y chromosomes, confirming a diagnosis of 48, XXYY syndrome. CONCLUSIONS: This study underscores the rare association of high myopia and grade 3 macular dysplasia with 48, XXYY syndrome. To our knowledge, this case marks the first recorded instance of macular dysplasia in a patient with 48, XXYY syndrome. This novel finding enhances our understanding of this syndrome's phenotypic variability.

Serum Lipocalin-2 Levels as a Biomarker in Pre- and Post-Pubertal Klinefelter Syndrome Patients: A Pilot Study.

Klinefelter syndrome (KS) is a male genetic disease caused by the presence of an extra X chromosome, causing endocrine disorders mainly responsible for a high rate of infertility and metabolic disorders in adulthood. Scientific research is interested in identifying new biomarkers that can be predictive or prognostic of alterations strictly connected to KS. Lipocalin-2 (LCN-2, also known as NGAL) is a small protein initially identified within neutrophils as a protein related to innate immunity. Serum LCN-2 estimation seems to be a useful tool in predicting the metabolic complications caused by several pathological conditions. However, little is known about its potential role in infertility conditions. The present pilot study aims to investigate the presence of LCN-2 in the serum of a group of pre-pubertal and post-pubertal children affected by KS, compared to healthy controls. We demonstrated for the first time the presence of elevated levels of LCN-2 in the serum of KS patients, compared to controls. This increase was accompanied, in pre-pubertal KS patients, by the loss of correlation with LH and HDL, which instead was present in the healthy individuals. Moreover, in all KS individuals, a positive correlation between LCN-2 and inhibin B serum concentration was found. Despite the limited size of the sample analyzed, our preliminary data encourage further studies to confirm the findings and to extend the study to KS adult patients, to verify the predictive/prognostic value of LCN-2 as new biomarker for metabolic diseases and infertility associated with the pathology.

Detection of chromosomal aneuploidy in ancient genomes.

Ancient DNA is a valuable tool for investigating genetic and evolutionary history that can also provide detailed profiles of the lives of ancient individuals. In this study, we develop a generalised computational approach to detect aneuploidies (atypical autosomal and sex chromosome karyotypes) in the ancient genetic record and distinguish such karyotypes from contamination. We confirm that aneuploidies can be detected even in low-coverage genomes ( ~ 0.0001-fold), common in ancient DNA. We apply this method to ancient skeletal remains from Britain to document the first instance of mosaic Turner syndrome (45,X0/46,XX) in the ancient genetic record in an Iron Age individual sequenced to average 9-fold coverage, the earliest known incidence of an individual with a 47,XYY karyotype from the Early Medieval period, as well as individuals with Klinefelter (47,XXY) and Down syndrome (47,XY, + 21). Overall, our approach provides an accessible and automated framework allowing for the detection of individuals with aneuploidies, which extends previous binary approaches. This tool can facilitate the interpretation of burial context and living conditions, as well as elucidate past perceptions of biological sex and people with diverse biological traits.

From Klinefelter Syndrome to High Grade Aneuploidies: Expanding the Gene-dosage Effect of Supernumerary X Chromosomes.

OBJECTIVE: High-grade aneuploidies of X and Y sex chromosomes (HGAs) are exceedingly rare and complex conditions. We aimed to investigate the effect of supernumerary X chromosomes (extra-Xs) on the clinical, hormonal, metabolic, and echocardiographic features of patients with HGAs. DESIGN AND METHODS: In a cross-sectional study, we compared 23 subjects with HGAs and 46 age-matched subjects with 47,XXY Klinefelter syndrome (KS), according to the number of extra-Xs: two (47,XXY and 48,XXYY), three (48,XXXY and 49,XXXYY), or four supernumerary Xs (49,XXXXY). A second cohort consisting of 46 pubertal stage-matched KS subjects was employed for validation. Clinical, hormonal, metabolic and ultrasonographic parameters were collected and analyzed. RESULTS: The increase in the number of extra-Xs was associated with a progressive adverse effect on height, pubertal development, testicular volume and function, adrenal steroidogenesis, and thyroid function. A progressive linear increase in ACTH and a decrease in cortisol/ACTH ratios were found. Weight and body mass index, Sertoli cell function, lipid profile, and glucose tolerance post-oral glucose tolerance test were all worse in the HGA cohort compared to KS. Cardiac evaluation revealed a linear association with reduced left and right end-diastolic diameters and reduced ejection fraction. CONCLUSION: The increase in the number of extra-Xs is associated with a "dose-dependent" progressive impairment in steroid producing glands, thyroid function, cardiac structure, and performance.

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.

X­chromosome loss rescues Sertoli cell maturation and spermatogenesis in Klinefelter syndrome.

Klinefelter syndrome (47,XXY) causes infertility with a testicular histology comprising two types of Sertoli cell-only tubules, representing mature and immature-like Sertoli cells, and occasionally focal spermatogenesis. Here, we show that the immature-like Sertoli cells highly expressed XIST and had two X-chromosomes, while the mature Sertoli cells lacked XIST expression and had only one X-chromosome. Sertoli cells supporting focal spermatogenesis also lacked XIST expression and the additional X-chromosome, while the spermatogonia expressed XIST despite having only one X-chromosome. XIST was expressed in Sertoli cells until puberty, where a gradual loss was observed. Our results suggest that a micro-mosaic loss of the additional X-chromosome is needed for Sertoli cells to mature and to allow focal spermatogenesis.

Hormone Therapy During Infancy or Early Childhood for Patients with Hypogonadotropic Hypogonadism, Klinefelter or Turner Syndrome: Has the Time Come?

Managing patients unable to produce sex steroids using gonadotropins to mimic minipuberty in hypogonadotropic hypogonadism, or sex steroids in patients with Klinefelter or Turner syndrome, is promising. There is a need to pursue research in this area, with large prospective cohorts and long-term data before these treatments can be routinely considered.

Giftedness and atypical sexual differentiation: enhanced perceptual functioning through estrogen deficiency instead of androgen excess.

Syndromic autism spectrum conditions (ASC), such as Klinefelter syndrome, also manifest hypogonadism. Compared to the popular Extreme Male Brain theory, the Enhanced Perceptual Functioning model explains the connection between ASC, savant traits, and giftedness more seamlessly, and their co-emergence with atypical sexual differentiation. Overexcitability of primary sensory inputs generates a relative enhancement of local to global processing of stimuli, hindering the abstraction of communication signals, in contrast to the extraordinary local information processing skills in some individuals. Weaker inhibitory function through gamma-aminobutyric acid type A (GABAA) receptors and the atypicality of synapse formation lead to this difference, and the formation of unique neural circuits that process external information. Additionally, deficiency in monitoring inner sensory information leads to alexithymia (inability to distinguish one's own emotions), which can be caused by hypoactivity of estrogen and oxytocin in the interoceptive neural circuits, comprising the anterior insular and cingulate gyri. These areas are also part of the Salience Network, which switches between the Central Executive Network for external tasks and the Default Mode Network for self-referential mind wandering. Exploring the possibility that estrogen deficiency since early development interrupts GABA shift, causing sensory processing atypicality, it helps to evaluate the co-occurrence of ASC with attention deficit hyperactivity disorder, dyslexia, and schizophrenia based on phenotypic and physiological bases. It also provides clues for understanding the common underpinnings of these neurodevelopmental disorders and gifted populations.

Alterations in Neural Activation During Facial Emotion Processing in Adolescent Male Participants With Klinefelter Syndrome.

OBJECTIVE: Klinefelter syndrome (KS) is the most common sex-chromosome aneuploidy (47,XXY), affecting 1 in 500 male participants. The phenotype of male participants with KS includes both physical features, such as tall stature and testicular insufficiency, and behavioral alterations, including difficulties in social functioning, anxiety, and depression. Studies examining underlying neural alterations associated with the behavioral phenotype, however, are sparse. We aimed to address this gap in knowledge using functional magnetic resonance imaging in conjunction with an emotion processing paradigm. METHOD: Functional magnetic resonance imaging was conducted on 38 children and adolescents with KS ( Mage = 12.85, SD = 2.45) and 47 typical developing (control) boys ( Mage = 12.04, SD = 1.82) as they completed a facial emotion processing task. Group differences in activation occurring during the processing of angry versus neutral faces were examined while controlling for age. RESULTS: The results indicated that relative to typically developing boys, boys with KS exhibited anomalous increases in activation of frontal, temporal, and occipital cortices. Within the KS group, secondary analyses indicated that greater activation in these regions was associated with more internalizing symptoms (e.g., anxiety, depression, withdrawn behaviors) and greater social impairments (e.g., social cognition, social communication, social motivation, social communication and interaction, functional communication). CONCLUSION: The findings from this study indicate a possible neural correlation for difficulties in social and emotional function in KS and add to a growing body of research aimed at increasing our understanding of neural biomarkers in this condition. Future studies that examine the influence of testosterone-replacement therapy on these differences are warranted.

Gonadotropins for pubertal induction in males with hypogonadotropic hypogonadism: systematic review and meta-analysis.

OBJECTIVE: Hypogonadotropic hypogonadism is characterized by inadequate secretion of pituitary gonadotropins, leading to absent, partial, or arrested puberty. In males, classical treatment with testosterone promotes virilization but not testicular growth or spermatogenesis. To quantify treatment practices and efficacy, we systematically reviewed all studies investigating gonadotropins for the achievement of pubertal outcomes in males with hypogonadotropic hypogonadism. DESIGN: Systematic review and meta-analysis. METHODS: A systematic review of Medline, Embase, Global Health, and PsycINFO databases in December 2022. Risk of Bias 2.0/Risk Of Bias In Non-randomized Studies of Interventions/National Heart, Lung, and Blood Institute tools for quality appraisal. Protocol registered on PROSPERO (CRD42022381713). RESULTS: After screening 3925 abstracts, 103 studies were identified including 5328 patients from 21 countries. The average age of participants was <25 years in 45.6% (n = 47) of studies. Studies utilized human chorionic gonadotropin (hCG) (n = 93, 90.3% of studies), human menopausal gonadotropin (n = 42, 40.8%), follicle-stimulating hormone (FSH) (n = 37, 35.9%), and gonadotropin-releasing hormone (28.2% n = 29). The median reported duration of treatment/follow-up was 18 months (interquartile range 10.5-24 months). Gonadotropins induced significant increases in testicular volume, penile size, and testosterone in over 98% of analyses. Spermatogenesis rates were higher with hCG + FSH (86%, 95% confidence interval [CI] 82%-91%) as compared with hCG alone (40%, 95% CI 25%-56%). However, study heterogeneity and treatment variability were high. CONCLUSIONS: This systematic review provides convincing evidence of the efficacy of gonadotropins for pubertal induction. However, there remains substantial heterogeneity in treatment choice, dose, duration, and outcomes assessed. Formal guidelines and randomized studies are needed.

Markers of Fertility in Adolescents With Chronic Endocrinopathies at Transition From Paediatric to Adult Care.

OBJECTIVE: During the process of transition from paediatric to adult health care, counselling concerning fertility is an important issue and is based mainly on serum markers of gonadal function. Here, we analysed these markers in adolescents with various underlying endocrine diseases at the time of transition. METHODS: After reaching near adult height and late puberty (girls: bone age [BA] ≥14 years, and boys: BA ≥16 years), we assessed stages of puberty according to Tanner and measured testes or ovarian volumes and serum markers of gonadal function (anti-Mullerian hormone [AMH], inhibin B, 17ß-estradiol, testosterone). RESULTS: One hundred and ten patients (56 females and 54 males) were included from May 2010 to March 2016 with multiple pituitary hormone deficiency (MPHD; n = 17), growth hormone deficiency (GHD; n = 35), Turner syndrome (TS; n = 27), short stature after being born small for gestational age (SGA; n = 20) and Klinefelter syndrome (KS; n = 11). Female and male adolescents exhibited mature secondary sexual characteristics. The levels of serum inhibin B and AMH were lower in TS and female MPHD than in GHD and SGA, each independently (p < 0.05). The levels of serum AMH were higher whereas serum inhibin B were lower in male MPHD and KS (p < 0.05). Ovary volumes were significantly smaller in patients with TS, and testicular volumes were smaller in patients with KS. CONCLUSIONS: After current established treatments with sex steroids, the development of secondary sexual characteristics was mature. However, impaired markers of fertility have been identified in patients with TS, KS and MPHD, reflecting gonadal dysgenesis in TS and KS, but gonadal immaturity in MPHD as gonadal gonadotropin stimulation is lacking throughout development. Consequently, in patients with MPHD, these markers cannot reliably predict individual fertility, which warrants consideration and incorporation in future treatment concepts.