The role of hypogonadism in Klinefelter syndrome

Comparison of Effects of Chorionic Gonadotropin Alfa and Anastrozole on Sperm Retrieval Rate in Patients with Non-Mosaic Klinefelter Syndrome Following Microdissection Testicular Sperm Extraction

Background and Objectives: This study aimed to compare the effects of choriogonadotropin alfa and anastrozole treatments on the success of sperm retrieval in patients with Klinefelter syndrome (KS) undergoing micro-TESE at our clinic. Materials and Methods: We conducted a retrospective review of a cohort including patients with non-mosaic KS who underwent micro-TESE for fertility treatment at the Reproductive Medicine Center of our university hospital. This study included 43 patients who had not received exogenous testosterone therapy prior to or during the procedure. Before surgical sperm retrieval, all patients received either choriogonadotropin alfa or anastrozole treatment based on their preference. Micro-TESE was performed on all patients after three months of treatment. Results: The overall SRR in the cohort post-micro-TESE was found to be 32.6%. There was a significant increase in post-treatment testosterone levels compared to pre-treatment levels. Upon dividing patients into two groups based on whether sperm was successfully retrieved, we observed significant improvements in testosterone levels in both groups following treatment. In the group presenting with successful sperm retrieval, 28.6% of patients had received choriogonadotropin alfa, while 71.4% had received anastrozole. No statistically significant difference was found between treatment groups in terms of micro-TESE success. Both choriogonadotropin alfa and anastrozole treatments resulted in significant improvements in testosterone levels following treatment compared to pre-operative levels. Furthermore, in the choriogonadotropin alfa group, there were significant decreases in follicle-stimulating hormone and luteinizing hormone levels, as well as a significant increase in estradiol levels after treatment. Post-treatment E2 levels were significantly lower in the anastrozole group than in the choriogonadotropin alfa group (p = 0.032), while the mean testicular volume was statistically significantly lower in the choriogonadotropin alfa group. Conclusions: This study suggests that anastrozole treatment before micro-TESE in patients with KS yields more successful results in terms of the SRR compared to choriogonadotropin alfa treatment.

X- vs. Y-chromosome influences on human behavior: a deep phenotypic comparison of psychopathology in XXY and XYY syndromes

BACKGROUND

Do different genetic disorders impart different psychiatric risk profiles? This question has major implications for biological and translational aspects of psychiatry, but has been difficult to tackle given limited access to shared batteries of fine-grained clinical data across genetic disorders.

METHODS

Using a new suite of generalizable analytic approaches, we examine gold-standard diagnostic ratings, scores on 66 dimensional measures of psychopathology, and measures of cognition and functioning in two different sex chromosome aneuploidies (SCAs)-Klinefelter (XXY/KS) and XYY syndrome (n = 102 and 64 vs. n = 74 and 60 matched XY controls, total n = 300). We focus on SCAs for their high collective prevalence, informativeness regarding differential X- vs. Y-chromosome effects, and potential relevance for normative sex differences.

RESULTS

We show that XXY/KS elevates rates for most psychiatric diagnoses as previously reported for XYY, but disproportionately so for anxiety disorders. Fine-mapping across all 66 traits provides a detailed profile of psychopathology in XXY/KS which is strongly correlated with that of XYY (r = .75 across traits) and robust to ascertainment biases, but reveals: (i) a greater penetrance of XYY than KS/XXY for most traits except mood/anxiety problems, and (ii) a disproportionate impact of XYY vs. XXY/KS on social problems. XXY/KS and XYY showed a similar coupling of psychopathology with adaptive function and caregiver strain, but not IQ.

CONCLUSIONS

This work provides new tools for deep-phenotypic comparisons of genetic disorders in psychiatry and uses these to detail unique and shared effects of the X- and Y-chromosome on human behavior.

Using Organoids to Model Sex Differences in the Human Brain

Sex differences are widespread during neurodevelopment and play a role in neuropsychiatric conditions such as autism, which is more prevalent in males than females. In humans, males have been shown to have larger brain volumes than females with development of the hippocampus and amygdala showing prominent sex differences. Mechanistically, sex steroids and sex chromosomes drive these differences in brain development, which seem to peak during prenatal and pubertal stages. Animal models have played a crucial role in understanding sex differences, but the study of human sex differences requires an experimental model that can recapitulate complex genetic traits. To fill this gap, human induced pluripotent stem cell-derived brain organoids are now being used to study how complex genetic traits influence prenatal brain development. For example, brain organoids from individuals with autism and individuals with X chromosome-linked Rett syndrome and fragile X syndrome have revealed prenatal differences in cell proliferation, a measure of brain volume differences, and excitatory-inhibitory imbalances. Brain organoids have also revealed increased neurogenesis of excitatory neurons due to androgens. However, despite growing interest in using brain organoids, several key challenges remain that affect its validity as a model system. In this review, we discuss how sex steroids and the sex chromosomes each contribute to sex differences in brain development. Then, we examine the role of X chromosome inactivation as a factor that drives sex differences. Finally, we discuss the combined challenges of modeling X chromosome inactivation and limitations of brain organoids that need to be taken into consideration when studying sex differences.

[Combination of Klinefelter syndrome and the classic form of congenital dysfunction of the adrenal cortex: clinical observation]

Congenital adrenal hyperplasia (CAH) is a defect in one of the enzymes or transport proteins involved in the synthesis of cortisol in the adrenal cortex. Virile form of CAH characterized by cortisol deficiency and hyperandrogenism. Klinefelter syndrome is one of the most frequent chromosomal diseases leading to the development of primary hypogonadism. The manifestation of these two diseases could cause difficulties in diagnosis and medical treatment that lead to adverse consequences and affect the quality of life.A 43-years-old patient consulted a physician complaining about the lack of erections for 4 years, breast enlargement. At the age of 3 years based on experienced growth of pubic hair, decreased level of 17-ketosteroids in the urine and genetic analysis diagnosis of CAH, virile form was suspected. Prednisone 5 mg daily was prescribed. At the age of 5, based on phenotypic features and karyotyping Klinefelter Syndrome (XXY) was diagnosed. At the age of 13, stimulating hormonal chorionic gonadotropin drug with only one course of 10 injections was prescribed. At the age of 18, the patient independently canceled the use of prednisone. Further, he did not receive medication therapy for CAH and Klinefelter syndrome. At the age of 42, adrenal CT revealed formation of the left adrenal gland. According to the results of the hormonal activity examination, high levels of aldosterone and renin were detected. A diagnosis of left adrenal aldosteroma was made and a left-sided adrenalectomy was performed. Histological examination diagnosis of aldosteroma did not confirmed. On physical examination, BMI 30 kg/m2, genoid type of obesity, right testicle isn`t palpated, left testicle is dense, reduced in size. Small penis size. Decreased level of total testosterone, normal level of SHBG, LH and FSH was revealed. Ultrasound of the scrotum organs revealed decrease in the size of the testicles and appendages, a volumetric formation of the right testicle. Thus, diagnosis of CAH, virile form and Klinefelter syndrome, primary hypogonadism, right-sided cryptorchidism was confirmed. Hydrocortisone 30 mg daily was prescribed. Hormone replacement therapy with testosterone preparations was not prescribed until surgical treatment of neoplasm of the right testicle will be performed. On the example of this clinical case, we have demonstrate a combination of two endocrine pathologies and serious mistakes were made in the management of this patient. The management of such patients requires a multidisciplinary approach, which will avoid mistakes and improve the prognosis and quality of life of these patients.

Environmental and Genetic Traffic in the Journey from Sperm to Offspring

Recent advancements in the understanding of how sperm develop into offspring have shown complex interactions between environmental influences and genetic factors. The past decade, marked by a research surge, has not only highlighted the profound impact of paternal contributions on fertility and reproductive outcomes but also revolutionized our comprehension by unveiling how parental factors sculpt traits in successive generations through mechanisms that extend beyond traditional inheritance patterns. Studies have shown that offspring are more susceptible to environmental factors, especially during critical phases of growth. While these factors are broadly detrimental to health, their effects are especially acute during these periods. Moving beyond the immutable nature of the genome, the epigenetic profile of cells emerges as a dynamic architecture. This flexibility renders it susceptible to environmental disruptions. The primary objective of this review is to shed light on the diverse processes through which environmental agents affect male reproductive capacity. Additionally, it explores the consequences of paternal environmental interactions, demonstrating how interactions can reverberate in the offspring. It encompasses direct genetic changes as well as a broad spectrum of epigenetic adaptations. By consolidating current empirically supported research, it offers an exhaustive perspective on the interwoven trajectories of the environment, genetics, and epigenetics in the elaborate transition from sperm to offspring.

The correlation between clinical features and ultrastructure of testis of non-mosaic Klinefelter's syndrome patients with hypogonadism and androgen deficiency: A case report

Background

Klinefelter Syndrome (KS) is a sex chromosomal syndrome usually with an extra X chromosome (47, XXY) in males, which has various phenotype (mosaicism 47, XXY/46, XY, or more chromosomes 48, XXXY, 49, XXXXY) and clinical features, including eunuchoid body proportions, abnormally long legs and arm span, gynecomastia, ynecomastia, absent or decreased facial and pubic hair, small hyalinized testes, small penis, below-normal verbal intelligence quotient, and learning difficulties. At present, there are no studies on the correlation between the clinical characteristics of patients with KS and the ultrastructural changes of intracellular organelles in testicular tissue in China.

Case presentation

Here we report the ultrastructure manifestation of the testis tissues in a KS patient with hypogonadism and androgen deficiency, to find a relationship between ultrastructural changes of organelles and spermatogenic dysfunction, clinical features, timing of surgery and metabolic abnormalities. It has been shown that the spermatocytes are absent and the ultrastructure of Sertoli cells and Leydig cells is obviously abnormal, which may lead to spermatogenic dysfunction, androgen deficiency, impaired glucose tolerance (IGT), and abdominal fat accumulation.

Conclusions

Based on the European Academy of Andrology (EAA) Gudilines on Klinefelter Syndrome, this study conducted a retrospective study on the diagnosis and treatment of one adult patient with KS, aiming to provide a standardized diagnosis and treatment for patients with KS. This study is also highly concerned with the correlation between the ultrastructural changes of target organs and clinical symptoms.

X- vs. Y-Chromosome Influences on Human Behavior: A Deep Phenotypic Comparison of Psychopathology in XXY and XYY Syndromes

Do different genetic disorders impart different psychiatric risk profiles? This question has major implications for biological and translational aspects of psychiatry, but has been difficult to tackle given limited access to shared batteries of fine-grained clinical data across genetic disorders. Using a new suite of generalizable analytic approaches, we examine gold-standard diagnostic ratings, scores on 66 dimensional measures of psychopathology, and measures of cognition and functioning in two different sex chromosome aneuploidies (SCAs) - Klinefelter (XXY/KS) and XYY syndrome (n=102 and 64 vs. n=74 and 60 matched XY controls, total n=300). We focus on SCAs for their high collective prevalence, informativeness regarding differential X- vs. Y-chromosome effects, and potential relevance for normative sex differences. We show that XXY/KS elevates rates for most psychiatric diagnoses as previously reported for XYY, but disproportionately so for anxiety disorders. Fine-mapping across all 66 traits provides a detailed profile of psychopathology in XXY/KS which is strongly correlated with that of XYY (r=.75 across traits) and robust to ascertainment biases, but reveals: (i) a greater penetrance of XYY than KS/XXY for most traits except mood/anxiety problems, and (ii) a disproportionate impact of XYY vs. XXY/KS on social problems. XXY/KS and XXY showed a similar coupling of psychopathology with adaptive function and caregiver strain, but not IQ. This work provides new tools for deep-phenotypic comparisons of genetic disorders in psychiatry and uses these to detail unique and shared effects of the X- and Y-chromosome on human behavior.

The Klinefelter Syndrome and Testicular Sperm Retrieval Outcomes

Klinefelter syndrome (KS), caused by the presence of an extra X chromosome, is the most prevalent chromosomal sexual anomaly, with an estimated incidence of 1:500/1000 per male live birth (karyotype 47,XXY). High stature, tiny testicles, small penis, gynecomastia, feminine body proportions and hair, visceral obesity, and testicular failure are all symptoms of KS. Endocrine (osteoporosis, obesity, diabetes), musculoskeletal, cardiovascular, autoimmune disorders, cancer, neurocognitive disabilities, and infertility are also outcomes of KS. Causal theories are discussed in addition to hormonal characteristics and testicular histology. The retrieval of spermatozoa from the testicles for subsequent use in assisted reproduction treatments is discussed in the final sections. Despite testicular atrophy, reproductive treatments allow excellent results, with rates of 40–60% of spermatozoa recovery, 60% of clinical pregnancy, and 50% of newborns. This is followed by a review on the predictive factors for successful sperm retrieval. The risks of passing on the genetic defect to children are also discussed. Although the risk is low (0.63%) when compared to the general population (0.5–1%), patients should be informed about embryo selection through pre-implantation genetic testing (avoids clinical termination of pregnancy). Finally, readers are directed to a number of reviews where they can enhance their understanding of comprehensive diagnosis, clinical care, and fertility preservation.

Neuroimmune Dysregulation in Prepubertal and Adolescent Individuals Affected by Klinefelter Syndrome

BACKGROUND

The syndrome Klinefelter syndrome (KS) is a genetic disorder due to an extra X chromosome in males. Many cases remain undiagnosed until the onset of major manifestations, which include hypergonadotropic hypogonadism and infertility. This condition is associated with many comorbidities that involve the cardiovascular, endocrine, and immune systems. Last but not the least, individuals with KS show a high risk of developing psychiatric and mood disorders in adult age.

OBJECTIVE

While many studies are accessible on KS in adult individuals, the neuroinflammatory condition in adolescent and prepubertal KS individuals is not fully known.

METHODS

Our study aims to evaluate in prepubertal and adolescent KS individuals, for the first time, the levels of the serum of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), cytokines having subtle roles in oxidative processes, and neuroinflammation with respect to the levels of TNF-α, TGF-β, MCP-1, IL-1α, IL-2, IL-6, IL-10, and IL-12 and oxidative stress by employing free oxygen radicals defense and free oxygen radicals test.

RESULTS

We found no changes in NGF and oxidative stress parameters, but BDNF decreased compared to healthy children. Quite interestingly, our data showed reduced levels of IL-2, IL-1α, IL- 12, IL-10, and IL-6 in prepubertal KS children.

CONCLUSION

The present study discloses disrupted immune system and neurotrophin pathways in KS children.

Genome-Wide Association Screening Determines Peripheral Players in Male Fertility Maintenance

Deciphering the functional relationships of genes resulting from genome-wide screens for polymorphisms that are associated with phenotypic variations can be challenging. However, given the common association with certain phenotypes, a functional link should exist. We have tested this prediction in newly sequenced exomes of altogether 100 men representing different states of fertility. Fertile subjects presented with normal semen parameters and had naturally fathered offspring. In contrast, infertile probands were involuntarily childless and had reduced sperm quantity and quality. Genome-wide association study (GWAS) linked twelve non-synonymous single-nucleotide polymorphisms (SNPs) to fertility variation between both cohorts. The SNPs localized to nine genes for which previous evidence is in line with a role in male fertility maintenance: ANAPC1, CES1, FAM131C, HLA-DRB1, KMT2C, NOMO1, SAA1, SRGAP2, and SUSD2. Most of the SNPs residing in these genes imply amino acid exchanges that should only moderately affect protein functionality. In addition, proteins encoded by genes from present GWAS occupied peripheral positions in a protein-protein interaction network, the backbone of which consisted of genes listed in the Online Mendelian Inheritance in Man (OMIM) database for their implication in male infertility. Suggestive of an indirect impact on male fertility, the genes focused were indeed linked to each other, albeit mediated by other interactants. Thus, the chances of identifying a central player in male infertility by GWAS could be limited in general. Furthermore, the SNPs determined and the genes containing these might prove to have potential as biomarkers in the diagnosis of male fertility.

Rare Double Aneuploidy (Down-Klinefelter Syndrome): A Case Report

Double aneuploidies, such as Down syndrome and sex chromosome aneuploidies, are relatively rare. One rare form of double aneuploidy, Down-Klinefelter syndrome, is described here. The phenotypic characteristics of a three-year-old child showed the presence of features typical of Down syndrome. He had a global developmental delay, small testes, and diabetes mellitus by 18 months of age. Regardless of the presenting clinical features, karyotyping should be performed in all patients with suspected Down syndrome. In Down-Klinefelter syndrome, anticipatory phenotype goes beyond the sum of individual syndromic characteristics.

Clinical features and prevalence of Klinefelter syndrome in transgender individuals: A systematic review

OBJECTIVE

Previous studies have suggested a higher prevalence of Klinefelter syndrome amongst transgender individuals. We undertook a systematic review to determine the prevalence of Klinefelter syndrome amongst transgender individuals presumed male at birth and summarize the clinical features and potential treatment implications for individuals with Klinefelter syndrome commencing gender-affirming hormone therapy.

DESIGN

Using preferred reporting items for systematic review and meta-analysis guidelines, we searched EMBASE, MEDLINE and the Cochrane Central Register of Controlled Trials (CENTRAL) up to 31 December 2021. All studies reporting on the prevalence or clinical features of transgender individuals with Klinefelter syndrome were included. This study is registered with the International Prospective Register of Systematic Reviews, number CRD42021227916.

RESULTS

Our search strategy retrieved 11 cohort studies comprising 1376 transgender individuals. In all, 14 of 1376 (1.02%) individuals were diagnosed with Klinefelter syndrome. Based on the seven studies in which karyotype was undertaken in all individuals, the prevalence is 9/1013 (0.88%; 95% CI, 0.41%-1.68%). Case reports highlight unique treatment considerations in this population, including azoospermia, venous thromboembolism, and monitoring of breast cancer and bone health.

CONCLUSIONS

Compared to the general population, observational studies document a higher prevalence of Klinefelter syndrome amongst transgender individuals, though underdiagnosis in the general population limits conclusions. Routine karyotype in transgender people initiating gender-affirming hormone therapy is not supported unless clinical features of Klinefelter syndrome, such as small testicular volume, or hypergonadotropic hypogonadism are present. Transgender individuals with Klinefelter syndrome need to manage a unique risk profile if they desire feminizing gender-affirming hormone therapy.

Metabolic and Nutritional Aspects in Paediatric Patients with Klinefelter Syndrome: A Narrative Review

Klinefelter syndrome is the most common sex chromosomal aneuploidy in males. It is well known that patients with this syndrome have greater mortality and morbidity compared to the general population due to cardiovascular diseases and endocrine metabolism disorders. This augmented risk is due both to hypogonadism and to the syndrome itself. Therefore, correct hormonal replacement therapy and early primary prevention are crucial to these patients. Even though different studies are available on this topic in adult patients, only a few authors have focused on the paediatric population. Thus, in this narrative review, we report the current knowledge of metabolic and nutritional aspects in children with Klinefelter syndrome.

An Adolescent Boy with Klinefelter Syndrome and 47,XXY/46,XX Mosaicism: Case Report and Review of Literature

Klinefelter syndrome is the most commonly reported sex chromosome abnormality. It is heavily underdiagnosed due to the substantial variability of clinical presentations but is generally characterized by small, firm testes, hypergonadotropic hypogonadism, and the absence of spermatogenesis. Most patients with Klinefelter syndrome have a 47,XXY genotype. If they present with mosaicism, two different cell lines are usually identified, an aneuploid 47,XXY cell line and a normal male 46,XY cell line. There are very few cases of 47,XXY mosaicism with the additional female cell line 46,XX described in the literature. We report a case of an adolescent with the male phenotype and a rare variant mosaic 47,XXY/46,XX karyotype who presented with painless bilateral gynaecomastia. 47,XXY and 46,XX mosaic cell lines were identified with GTG-banding and further characterized using fluorescent in situ hybridization. We summarized the available clinical presentations of reported male patients with 47,XXY/46,XX mosaicism. To improve the clinical management and quality of life in individuals with rare and cryptic genomic imbalances, the genetic diagnosis would need to be extended to atypical cases.

Klinefelter syndrome in an adolescent with severe obesity, insulin resistance, and hyperlipidemia, successfully treated with testosterone replacement therapy

Klinefelter syndrome (KS) is a sex chromosome disorder characterized by the presence of one or more extra X chromosomes. KS is well known by the common karyotype 47, XXY and presents as male infertility with hypogonadism in adults. Pediatric patients with KS commonly show neurodevelopmental disorders and cryptorchidism. We have reported a case of a 14-yr-old boy with KS and severe obesity (body mass index, 38.1 kg/m²), insulin (IRI) resistance (homeostatic model assessment 1 IRI resistance, 9.26), hyperlipidemia (serum low-density lipoprotein cholesterol level, 192 mg/dL; serum triglyceride level, 239 mg/dL), hypergonadotropic hypogonadism, and learning difficulties. The karyotype was 47, XXY, t(4;5) (q21.2;q32). Initially, he was unwilling to accept dietary restrictions and perform physical exercise against obesity. Testosterone replacement therapy was initiated at 16 years of age, which successfully improved the body composition, IRI resistance, and hyperlipidemia and increased the serum testosterone levels. Additionally, he adhered to recommendations for exercise and dietary restrictions. Patients with KS have risks of obesity and metabolic syndrome with sarcopenic conditions due to hypergonadotropic hypogonadism. Pediatricians should be aware of KS as a primary disease causing obesity. Testosterone replacement therapy could help ameliorate obesity and its comorbidities in patients with obesity and KS.

Elevated sweat chloride test: is it always cystic fibrosis?

BACKGROUND

The sweat chloride test (ST) is the gold standard for cystic fibrosis (CF) diagnosis in symptomatic patients, within the newborn screening and in the follow-up of CF patients during molecular therapies. However, false positives have been reported in patients with different diseases. We describe and discuss 4 cases due to different clinical conditions in which we recorded false positive ST, and the test remained altered for a period of varying length.

CASES PRESENTATION

Case 1: Eight months old female child suffering from constipation, recurrent vomiting and failure to thrive, family history of recurrent pancreatitis without mutations in the PRSS1 and SPINK1 genes. Both ST and fecal elastase were altered although no CFTR gene mutations were found. Due to rapid clinical deterioration, celiac disease was suspected and diagnosed by laboratory tests and intestinal biopsy. After 2 weeks of gluten-free diet ST and fecal elastase normalized. Case 2: 14 months old male suffering from bilateral renal dysplasia, episodes of metabolic alkalosis, recurrent respiratory infections and recurrent vomiting. The child had more ST positives, but no CFTR mutations were found. During follow-up, he developed sensorineural hearing loss and an atrial septic defect was found. Finally, a diagnosis of Klinefelter was made, but the ST normalized several years later. Case 3 and 4: Two boys with stubborn constipation and fecal occlusion treated with Poly Ethylene Glycol (PEG) with salts showed pathological ST. The test returned normal a few days after stopping treatment.

CONCLUSIONS

We hypotesized the possible causes of ST alteration in these conditions: in celiac disease it could be due to a transient dysregulation of the aquaporins, rapidly reversed by the diet; in Klinefelter, it may be due to stable pubertal hypoandrogenism; while, the PEG formulation itself contains salts that can temporarily alter ST.

Quality of life in Klinefelter patients on testosterone replacement therapy compared to healthy controls: an observational study on the impact of psychological distress, personality traits, and coping strategies

PURPOSE

We aimed to verify if 1 year-testosterone-replacement therapy could produce a psychopathological recovery and a satisfactory quality of life in Klinefelter syndrome (KS) patients compared to matched healthy controls. Further, we analyzed personality traits and coping strategies, an issue not yet examined in androgen-treated KS patients. We also enquired whether any of the sociodemographic and psychological variables might predict a patient's general and sexual life satisfaction.

METHODS

The Quality of Life Enjoyment and Satisfaction Questionnaire and the Temperament and Character Inventory-Revised were administered to both 23 KS patients and matched healthy subjects. Psychopathology was investigated by the Symptom Checklist-90-Revised (SCL-90-R) and the Mini-mental State Examination. The COPE Inventory was used to identify cognitive and behavioral strategies to manage disease-related distress.

RESULTS

In testosterone-treated KS patients, when compared with controls, SCL-90-R subscales analysis evidenced high psychological distress, mainly presented as obsessive thoughts, hanger-hostility, phobias, and psychoticism. Self-directedness and self-transcendence, along with the prevalent use of emotion-focused coping strategies, outlined the personality of our KS patients. Depression and somatization proved to be predictors of general life dissatisfaction. Depression, anger-hostility, and paranoid ideation, instead, emerged as predictors of sexual life dissatisfaction.

CONCLUSION

Endocrinologists should cooperate with mental health providers to foster a better outcome of the disease in KS patients.

Clinical manifestation, diagnosis, and treatment of Klinefelter syndrome

Klinefelter syndrome is the most common congenital chromosomal syndrome in men. Clinical manifestations of Klinefelter syndrome vary greatly depending on the level of expression of the added X chromosome, the sensitivity of the androgen receptor, and the testosterone level. On average, the likelihood of a lifetime diagnosis of Klinefelter syndrome patients is less than 40%, and more than 60% of patients are unaware of their condition. Klinefelter syndrome patients in infancy sometimes have speech impairment; however, there are more cases without symptoms. In the early stages of puberty, there are many normal puberty development cases, but after mid-puberty, secondary sexual characteristics stop progressing. In adulthood, it is often diagnosed as a non-obstructive azoospermia disease. After middle-age, an increase in various metabolic disorders due to testosterone reduction appears as the main symptom. Testosterone treatment can promote the development of secondary sexual characteristics from puberty. Diagnosing a patient with Klinefelter syndrome due to infertility in adulthood may cause a psychological shock; therefore, a psychotherapeutic approach is also essential. Klinefelter syndrome is a disease that requires lifelong management, and in most cases the quality of life of patients and their families can be improved with appropriate therapeutic intervention. Because there are many cases without symptoms, it is important to screen suspected patients through active chromosomal testing.

Testicular blood supply is altered in the 41,XXY* Klinefelter syndrome mouse model

Hypergonadotropic hypogonadism is a major feature of Klinefelter syndrome (KS), assumed to be caused by testicular hormone resistance. It was previously shown that intratesticular testosterone levels in vivo and Leydig cell function in vitro seem to be normal indicating other functional constraints. We hypothesized that impaired testicular vascularization/blood flow could be a co-factor to the observed hypergonadotropic hypogonadism. We evaluated the testicular vascular system by measuring blood vessel sizes during postnatal development and testis blood flow in adult 41,XX^Y* mice. Proportional distribution and size of blood vessels were analyzed during testicular development (1, 3, 5, 7, 10, 21 dpp, 15 wpp). While ratios of the vessel/testis area were different at 15 wpp only, a lower number of smaller and mid-sized blood vessels were detected in adult KS mice. For testicular blood flow determination we applied contrast enhanced ultrasound. Floating and reperfusion time for testicular blood flow was increased in 41,XX^Y* mice (floating: XY* 28.8 ± 1.69 s vs XX^Y* 44.6 ± 5.6 s, p = 0.0192; reperfusion XY* 19.7 ± 2.8 s vs XX^Y*: 29.9 ± 6.2 s, p = 0.0134), indicating a diminished blood supply. Our data strengthen the concept that an impaired vascularization either in conjunction or as a result of altered KS testicular architecture contributes to hormone resistance.

Role of treatment with human chorionic gonadotropin and clinical parameters on testicular sperm recovery with microdissection testicular sperm extraction and intracytoplasmic sperm injection outcomes in 184 Klinefelter syndrome patients

OBJECTIVE

To investigate whether preoperative human chorionic gonadotropin (hCG) treatment can help predict the outcomes of microdissection testicular sperm extraction (micro-TESE) and affect fertility outcomes in non-mosaic Klinefelter syndrome (KS) patients.

DESIGN

Retrospective cohort study.

SETTING

University-affiliated fertility center.

PATIENT(S)

A total of 184 non-mosaic KS patients who underwent micro-TESE with or without preoperative hCG treatment from January 2016 to July 2019.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Sperm retrieval rate (SRR) with and without hCG treatment, logistic models analysis.

RESULT(S)

Eighty KS patients (43.5%) had successful sperm retrievals after micro-TESE. There was no statistically significant difference in the SRR between the group who received hCG treatment and the group that did not (44.0% vs. 43.3%). Logistic regression analyses demonstrated that the hCG treatment had no statistically significant effect on successful sperm retrieval. However, higher preoperative testosterone (T) levels seemed to be associated with a higher probability of successful sperm retrieval (multivariate adjusted odds ratio 1.09; 95% confidence interval [CI], 1.04-1.16). The prediction model for SRR on KS patients had an area under the curve of 67.3% (95% CI, 59.3-75.3%). In the hCG treatment group, the data indicated that the three parameters of testicular volume, pretreatment T level, and alterations of T were associated with the probability of successful sperm retrieval. Moreover, hCG therapy did not affect intracytoplasmic sperm injection (ICSI) outcomes. No differences in the pregnancy rate or live-birth rate were observed between the two groups.

CONCLUSION(S)

Therapy with hCG does not affect SRR or ICSI outcomes of non-mosaic KS patients. However, preoperative T levels, whether treated with hCG or not, can predict the chance of sperm retrieval with micro-TESE.

External and Genetic Conditions Determining Male Infertility

We explain environmental and genetic factors determining male genetic conditions and infertility and evaluate the significance of environmental stressors in shaping defensive responses, which is used in the diagnosis and treatment of male infertility. This is done through the impact of external and internal stressors and their instability on sperm parameters and their contribution to immunogenetic disorders and hazardous DNA mutations. As chemical compounds and physical factors play an important role in the induction of immunogenetic disorders and affect the activity of enzymatic and non-enzymatic responses, causing oxidative stress, and leading to apoptosis, they downgrade semen quality. These factors are closely connected with male reproductive potential since genetic polymorphisms and mutations in chromosomes 7, X, and Y critically impact on spermatogenesis. Microdeletions in the Azoospermic Factor AZF region directly cause defective sperm production. Among mutations in chromosome 7, impairments in the cystic fibrosis transmembrane conductance regulator CFTR gene are destructive for fertility in cystic fibrosis, when spermatic ducts undergo complete obstruction. This problem was not previously analyzed in such a form. Alongside karyotype abnormalities AZF microdeletions are the reason of spermatogenic failure. Amongst AZF genes, the deleted in azoospermia DAZ gene family is reported as most frequently deleted AZF. Screening of AZF microdeletions is useful in explaining idiopathic cases of male infertility as well as in genetic consulting prior to assisted reproduction. Based on the current state of research we answer the following questions: (1) How do environmental stressors lessen the quality of sperm and reduce male fertility; (2) which chemical elements induce oxidative stress and immunogenetic changes in the male reproductive system; (3) how do polymorphisms correlate with changes in reproductive potential and pro-antioxidative mechanisms as markers of pathophysiological disturbances of the male reproductive condition; (4) how do environmental stressors of immunogenetic disorders accompany male infertility and responses; and (5) what is the distribution and prevalence of environmental and genetic risk factors.

Effects of acute hCG stimulation on serum INSL3 and 25-OH vitamin D in Klinefelter syndrome

BACKGROUND

It has recently been suggested that the hypergonadotropic hypogonadism characterizing Klinefelter syndrome (KS) might not be due to a steroidogenic dysfunction per se, but mainly to an altered testosterone (T) secretion into the bloodstream. However, the Leydig cell functionality remains incompletely studied in KS, and new markers should be considered. Previous data indicated that chronic hCG stimulation influences the production of both insulin-like peptide 3 (INSL3) and 25-hydroxy-vitamin D (25-VD) in eugonadal men.

AIM OF THE STUDY

To evaluate INSL3 and 25-VD serum levels, as markers of Leydig cell functionality, in association with sex steroids, after an acute hCG test in a group of KS patients and healthy volunteers.

METHODS

A retrospective analysis of a prospective case-control clinical trial was carried out. KS patients (n = 11) and age-matched healthy controls (n = 11) provided a basal blood sample (V0) immediately followed by a single intramuscular injection of hCG 5000 IU. Blood samples were taken in the following five days (V1-V5).

RESULTS

At baseline, INSL3 was lower in KS patients compared with controls (P = .007). When adjusted for INSL3 levels, the production of steroids was similar between KS patients and controls. 25-VD was in the insufficient range both in KS patients and in controls and was not different (P = .064). Acute hCG stimulation increased neither INSL3 nor 25-VD in both KS patients and controls. In controls, an inverse correlation was detected between INSL3 levels and body mass index (P = .020) and waist circumference (P = .020).

CONCLUSIONS

INSL3 secretion is independent from steroidogenesis, and its production is mostly not influenced by acute hCG stimulation both in KS men and in controls. INSL3 serum levels should be considered as a marker of Leydig cell differentiation and numbers rather than steroidogenesis. 25-VD serum levels are also not increased by a single acute hCG administration, which was not able to restore the normal concentrations of 25-VD.

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

INTRODUCTION AND OBJECTIVES

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.

METHODS

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) (≥3.03 ng/mL) and normal luteinizing hormone (LH) (≤9.4 mUI/mL)], secondary hypogonadism [low tT (≤3.03 ng/mL) and low/normal LH (≤9.4 mUI/mL)], primary hypogonadism [low tT (≤3.03 ng/mL) and elevated LH (≥9.4 mUI/mL)], and compensated hypogonadism [normal tT (≥3.03 ng/mL) and elevated LH (≥9.4 mUI/mL)]. Descriptive statistics tested the association between clinical characteristics and laboratory values among the four groups.

RESULTS

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.

CONCLUSIONS

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.

Treatment of Hidradenitis Suppurativa Patient with Klinefelter Syndrome by Adalimumab

Hidradenitis suppurativa (HS) is a chronic, inflammatory and painful skin disease with recurrent nodules and tracts involving the intertriginous regions. It is known that the patient with HS shows an increased risk of metabolic disorders such as diabetes, metabolic syndrome and autoimmune diseases. Klinefelter syndrome (KS) is a sex chromosomal disorder occurring in males due to an abnormality of sexual differentiation, characterized by 47, XXY karyotype. Also, KS is related with somatic comorbidities such as metabolic syndrome, autoimmune and rheumatologic disorders as HS is. We report a HS patient with KS who shows a big improvement while on tumor necrosis factor-alpha inhibitor treatment.

Relative hyperestrogenism in Klinefelter Syndrome: results from a meta-analysis

OBJECTIVE

Klinefelter Syndrome (KS) is classically described as characterized by hyperestrogenism, although solid evidence is lacking. This study aims to test the hypothesis that men with KS have higher serum estradiol than normal controls.

DESIGN

Meta-analysis of all studies extracted by MEDLINE from 1942 to 31 January 2018. All studies reporting serum estradiol measurement were considered, among them only case-control studies were included in the meta-analysis.

METHODS

Meta-analysis was conducted according to the PRISMA statement using RevMan.

RESULTS

Out of 4120 articles, 23 case-control studies, 14 case series, and 19 case reports reported data on serum estradiol. A total of 707 KS and 1019 controls were included in the meta-analysis. Serum estradiol was slightly, but significantly higher in KS than controls (mean difference 4.25 pg/mL; CI: 0.41, 8.10 pg/mL; p = 0.030). This difference was lost considering only studies using estradiol assays with good accuracy (5.48 pg/mL, CI: -2.11, 13.07 pg/mL; p = 0.160). Serum testosterone and estradiol/testosterone ratio were significantly lower and higher in KS than controls, respectively. Data from KS case series and case reports confirmed that serum estradiol is within the normal ranges.

CONCLUSIONS

Serum estradiol is not increased in KS although slightly higher than controls. However, the meta-analysis that included only studies using a serum estradiol assay with good accuracy showed no difference in serum estradiol between KS and controls. The traditional belief that KS is associated with elevated serum estradiol should be reconsidered. This meta-analysis shows that men with KS have relative hyperestrogenism (increased estradiol/testosterone ratio) compared to controls.

Klinefelter syndrome: From pediatrics to geriatrics

BACKGROUND

Klinefelter syndrome (KS) is one of the major causes of nonobstructive azoospermia (NOA). Microdissection testicular sperm extraction (micro-TESE) is often performed to retrieve sperm. Infertility specialists have to care for KS patients on a lifelong basis.

METHODS

Based on a literature review and our own experience, male infertility treatment and KS pathophysiology were considered on a lifelong basis.

MAIN FINDINGS

Patients diagnosed early often have an increased number of aberrant X chromosomes. Cryptorchidism and hypospadias are often found, and surgical correction is required. Cryopreservation of testicular sperm during adolescence is an issue of debate because the sperm retrieval rate (SRR) in KS patients decreases with age. The SRR in adult KS patients is higher than that in other patients with NOA; however, low testosterone levels after micro-TESE will lower the general health and quality of life. KS men face a number of comorbidities, such as malignancies, metabolic syndrome, diabetes, cardiovascular disease, bone disease, and immune diseases, which ultimately results in increased mortality rates.

CONCLUSION

A deeper understanding of the pathophysiology of KS and the histories of KS patients before they seek infertility treatment, during which discussions with multidisciplinary teams are sometimes needed, will help to properly treat these patients.

A rare variety of congenital adrenal hyperplasia with mosaic Klinefelter syndrome: a unique combination presenting with ambiguous genitalia and sexual precocity

Congenital adrenal hyperplasia (CAH) due to the three-beta-hydroxysteroid-dehydrogenase (3β-HSD) enzyme deficiency is a rare autosomal recessive disorder presenting with sexual precocity in a phenotypic male. Klinefelter syndrome (KS) is the most common sex chromosome aneuploidy presenting with hypergonadotropic hypogonadism in a male. However, only a handful of cases of mosaic KS have been described in the literature. The co-existence of mosaic KS with CAH due to 3β-HSD enzyme deficiency portrays a unique diagnostic paradox where features of gonadal androgen deficiency are masked by simultaneous adrenal androgen excess. Here, we report a 7-year-old phenotypic male boy who, at birth presented with ambiguous genitalia, probably a microphallus with penoscrotal hypospadias. Later on, he developed accelerated growth with advanced bone age, premature pubarche, phallic enlargement and hyperpigmentation. Biochemically, the patient was proven to have CAH due to 3β-HSD deficiency. However, the co-existence of bilateral cryptorchidism made us to consider the possibility of hypogonadism as well, and it was further explained by concurrent existence of mosaic KS (47,XXY/46,XX). He was started on glucocorticoid and mineralocorticoid replacement and underwent right-sided orchidopexy on a later date. He showed significant clinical and biochemical improvement on subsequent follow-up. However, the declining value of serum testosterone was accompanied by rising level of FSH thereby unmasking hypergonadotropic hypogonadism due to mosaic KS. In future, we are planning to place him on androgen replacement as well. Learning points: •• Ambiguous genitalia with subsequent development of sexual precocity in a phenotypic male points towards some unusual varieties of CAH. •• High level of serum testosterone, adrenal androgen, plasma ACTH and low basal cortisol are proof of CAH, whereas elevated level of 17-OH pregnenolone is biochemical marker of 3β-HSD enzyme deficiency. •• Final diagnosis can be obtained with sequencing of HSD3B2 gene showing various mutations. •• Presence of bilateral cryptorchidism in such a patient may be due to underlying hypogonadism. •• Karyotyping in such patient may rarely show mosaic KS (47,XXY/46,XX) and there might be unmasking of hypergonadotropic hypogonadism resulting from adrenal androgen suppression from glucocorticoid treatment.

Klinefelter syndrome: more than hypogonadism

Klinefelter syndrome (KS) is the most frequent chromosome disorder in males (1:650 newborn males), defined by 47,XXY karyotype. The classical phenotype is that of a tall male with relatively long legs, small, firm testes and gynecomastia. Azoospermia and infertility are almost inevitably present, but may be overcome by TESE and ICSI. Nevertheless, a broad spectrum of phenotypes has been described and more than 70% of the actually existing KS men may remain undiagnosed throughout their lifespan. Accordingly, hypogonadism is usually not evident until early adulthood and progresses with ageing. KS patients present a series of comorbidities that increase morbidity and mortality by 40%. Such disturbances are the impaired metabolic profile (obesity, dyslipidemia, insulin resistance) and a tendency to thrombosis, which all favor cardiovascular disease. They also present susceptibility for specific neoplasias (breast cancer, extragonadal germ cell tumors), autoimmune diseases as well as osteoporosis and bone fractures. Moreover, KS has been associated with verbal processing and attention deficits as well as social skill impairments, leading KS individuals to academic and professional achievements inferior to those of their peers of comparable socio-economic status. Nevertheless, the majority fall within the average range regarding their intellectual abilities and adaptive functioning. Testosterone replacement therapy (TRT) is the mainstay of treatment in hypogonadal KS patients; however, randomized trials are needed to determine optimal therapeutic regimens and follow-up schedules.

Klinefelter Syndrome: Integrating Genetics, Neuropsychology, and Endocrinology

Although first identified over 70 years ago, Klinefelter syndrome (KS) continues to pose substantial diagnostic challenges, as many patients are still misdiagnosed, or remain undiagnosed. In fact, as few as 25% of patients with KS are accurately diagnosed and most of these diagnoses are not made until adulthood. Classic characteristics of KS include small testes, infertility, hypergonadothropic hypogonadism, and cognitive impairment. However, the pathophysiology behind KS is not well understood, although genetic effects are also thought to play a role. For example, recent developments in genetics and genomics point to a fundamental change in our understanding of KS, with global epigenetic and RNA expression changes playing a central role for the phenotype. KS is also associated with more general health markers, including higher morbidity and mortality rates and lower socioeconomic status (which likely affect both morbidity and mortality). In addition, hypogonadism is associated with greater risk of metabolic syndrome, type 2 diabetes, cardiovascular disease, breast cancer, and extragonadal germ cell tumors. Medical treatment typically focuses on testosterone replacement therapy (TRT), although the effects of this therapy have not been studied rigorously, and future studies need to evaluate the effects of TRT on metabolic risk and neurocognitive outcomes. This review presents a comprehensive interdisciplinary examination of recent developments in genetic, endocrine, and neurocognitive science, including the study of animal models. It provides a number of recommendations for improving the effectiveness of research and clinical practice, including neonatal KS screening programs, and a multidisciplinary approach to KS treatment from childhood until senescence.

Long-term effect of testosterone replacement therapy on bone in hypogonadal men with Klinefelter Syndrome

PURPOSE

To assess different aspects of bone damage in untreated adult patients with Klinefelter Syndrome (KS) before and during testosterone replacement therapy (TRT).

METHODS

Fifteen untreated hypogonadal men with KS and 26 control subjects (C) matched for age and BMI were recruited. Sex hormone levels were measured in all subjects. Lumbar spine (LS) and femoral (neck: FN and total hip: TH) bone mineral density (BMD), trabecular bone score (TBS), hip structure analysis (HSA) and fat measures (percentage of fat mass, android/gynoid ratio and visceral adipose tissue) were evaluated by DEXA. In KS patients, blood analysis and DEXA measurements were assessed at baseline and repeated yearly for three years during TRT.

RESULTS

Fat measures were significantly higher in KS than C (p < 0.01). In contrast, mean LS, FN and TH BMD were significantly reduced in KS compared to C (p < 0.01), while there was no difference in TBS. HSA revealed a significantly lower cortical thickness and significantly higher buckling ratio in KS compared to C at all femoral sites (p < 0.01). In KS patients, TRT significantly increased BMD at LS only, but did not improve TBS and HSA parameters. Fat measures were inversely associated with TBS values, and TRT did not influence this relationship.

CONCLUSIONS

In untreated hypogonadal men with KS, lumbar and femoral BMD was reduced, and femoral bone quality was impaired. Adiposity seemed to have a detrimental effect on lumbar bone microarchitecture, as indirectly evaluated by TBS. However, TRT failed to remedy these negative effects on bone.

Salivary testosterone in relation to social cognition and social anxiety in children and adolescents with 47,XXY (Klinefelter syndrome)

Background

Approximately 1 in 650 boys are born with an extra X chromosome. Boys and men with 47,XXY (Klinefelter syndrome) are at risk for neurodevelopmental disorders and specific cognitive impairments. This study was focused on social anxiety and social cognition. The aim was to assess if these aspects of the phenotype are related to testosterone deficiency, which is typically seen in 47,XXY from puberty onwards.

Methods

In the study 20 boys with 47,XXY and 25 non-clinical controls between 8 and 19 years participated. None had ever used testosterone supplements. Cognitive tests measuring the labeling of facial expressions and perspective taking (Theory of Mind) were administered. Self-report questionnaires were used to assess social anxiety. Testosterone was measured in saliva.

Results

Within the 47,XXY group lower levels of salivary testosterone were significantly associated with higher levels of social anxiety. The correlation was strong, andindependent of age and pubertal development. However, salivary levels of testosterone were uncorrelated to social cognitive skills.

Discussion

These findings point out that lower testosterone levels might contribute to high social anxiety in 47,XXY, suggesting that anxiety should be monitored in pubertal boys with XXY presenting with testosterone deficiency. This should be done in addition to exploring cognitive behavioral therapy or psychopharmacologic treatments targeting anxiety, which are more evidence based. In contrast, testosterone levels were not associated with social cognitive functioning, suggesting that other mechanisms are driving vulnerabilities in this domain.

Neuroanatomical and molecular correlates of cognitive and behavioural outcomes in hypogonadal males

Robust epidemiological, clinical and laboratory evidence supports emerging roles for the sex steroids in such domains as neurodevelopment, behaviour, learning and cognition. Regions of the mammalian brain that are involved in cognitive development and memory do not only express the classical nuclear androgen receptor, but also the non-genomic membrane receptor, which is a G protein-coupled receptor that mediates some rapid effects of the androgens on neurogenesis and synaptic plasticity. Under physiological conditions, hippocampal neurons do express the enzyme aromatase, and therefore actively aromatize testosterone to oestradiol. Although glial expression of the aromatase enzyme is minimal, increased expression following injury suggests a role for sex steroids in neuroprotection. It is therefore plausible to deduce that low levels of circulating androgens in males would perturb neuronal functions in relation to cognition and memory, as well as neural repair following injury. The present review is an overview of some roles of the sex steroids on cognitive function in males, and the neuroanatomical and molecular underpinnings of some behavioural and cognitive deficits characteristic of such genetic disorders noted for low androgen levels, including Klinefelter syndrome, Bardet-Biedl syndrome, Kallman syndrome and Prader-Willi syndrome. Recent literature in relation to some behavioural and cognitive changes secondary to surgical and pharmacological castration are also appraised.

Androgen receptor CAG repeat polymorphism is not associated with insulin resistance and diabetes among South Asian males

Objective

To study relationship between androgen receptor (AR) CAG repeat polymorphism, insulin resistance (IR), β-cell function and other clinical/biochemical parameters in ethnic South Asian adults. A case (males with diabetes), control (males without diabetes) study, was conducted and 110 males were invited. Anthropometry, blood pressure and biochemical parameters (fasting Insulin, blood sugar, HbA1c and lipid profile) were measured. IR and β-cell function was calculated. A multiple-linear-regression analysis was performed, using number of AR CAG repeats as the continuous dependent variable.

Results

Sample size was 100 (response rate—90.9%, cases—53). Mean age was 49.6 ± 10.7 years. CAG repeat length did not show any significant correlation with IR or β-cell function. In all males there was a significant correlation between number of AR CAG repeats and systolic blood pressure (r = 0.25; p = 0.016), diastolic blood pressure (r = 0.21; p = 0.045), total cholesterol (r = − 0.22; p = 0.037) and low-density lipoprotein cholesterol (r = − 0.22; p = 0.037). Only total cholesterol (β = − 4.41; p < 0.001) and estrogen (β = 2.25; p = 0.03) were significantly associated with number of AR CAG repeats in regression analysis. In conclusion, AR CAG repeat length did not show any significant correlation with IR or β-cell function. Positive association of AR CAG with systolic and diastolic blood pressure and negative association of AR CAG with total and low-density lipoprotein cholesterol deserves further attention.

Genetic Basis for Sex Differences in Obesity and Lipid Metabolism

Men and women exhibit significant differences in obesity, cardiovascular disease, and diabetes. To provide better diagnosis and treatment for both sexes, it is important to identify factors that underlie the observed sex differences. Traditionally, sex differences have been attributed to the differential effects of male and female gonadal secretions (commonly referred to as sex hormones), which substantially influence many aspects of metabolism and related diseases. Less appreciated as a contributor to sex differences are the fundamental genetic differences between males and females, which are ultimately determined by the presence of an XX or XY sex chromosome complement. Here, we review the mechanisms by which gonadal hormones and sex chromosome complement each contribute to lipid metabolism and associated diseases, and the current approaches that are used to study them. We focus particularly on genetic approaches including genome-wide association studies in humans and mice, -omics and systems genetics approaches, and unique experimental mouse models that allow distinction between gonadal and sex chromosome effects.

The steroid response to human chorionic gonadotropin (hCG) stimulation in men with Klinefelter syndrome does not change using immunoassay or mass spectrometry

PURPOSE

Liquid-chromatography tandem mass-spectrometry (LC-MS/MS) was developed in parallel to Immunoassays (IAs) and today is proposed as the "gold standard" for steroid assays. Leydig cells of men with Klinefelter syndrome (KS) are able to respond to human chorionic gonadotropin (hCG) stimulation, even if testosterone (T) production was impaired. The aim was to evaluate how results obtained by IAs and LC-MS/MS can differently impact on the outcome of a clinical research on gonadal steroidogenesis after hCG stimulation.

METHODS

A longitudinal, prospective, case-control clinical trial. (clinicaltrial.gov NCT02788136) was carried out, enrolling KS men and healthy age-matched controls, stimulated by hCG administration. Serum steroids were evaluated at baseline and for 5 days after intramuscular injection of 5000 IU hCG using both IAs and LC-MS/MS.

RESULTS

13 KS patients (36 ± 9 years) not receiving T replacement therapy and 14 controls (32 ± 8 years) were enrolled. T, progesterone, cortisol, 17-hydroxy-progesterone (17OHP) and androstenedione, were significantly higher using IAs than LC-MS/MS. IAs and LC-MS/MS showed direct correlation for all five steroids, although the constant overestimation detected by IAs. Either methodology found the same 17OHP and T increasing profile after hCG stimulation, with equal areas under the curves (AUCs).

CONCLUSIONS

Although a linearity between IA and LC-MS/MS is demonstrated, LC-MS/MS is more sensitive and accurate, whereas IA shows a constant overestimation of sex steroid levels. This result suggests the need of reference intervals built on the specific assay. This fundamental difference between these two methodologies opens a deep reconsideration of what is needed to improve the accuracy of steroid hormone assays.

Long-term follow-up of a child with Klinefelter syndrome and achondroplasia from infancy to 16 years

BACKGROUND

Achondroplasia (ACH), an autosomal dominant skeletal dysplasia, occurs in approximately 1:20,000 births. On the other hand, 47,XXY aneuploidy (Klinefelter syndrome [KS]) is the most common sex chromosome disorder, with a prevalence of approximately 1:600 males. To the best of our knowledge, only five cases of patients presenting both ACH and KS have been reported to date in the international literature. However, none of these cases has been longitudinally followed during the entire childhood.

CASE PRESENTATION

We report a male patient with ACH and KS, diagnosed in early infancy because of his typical phenotype of ACH. The diagnosis was confirmed by molecular analysis revealing a de novo heterozygous 1138 G-to-A mutation of the FGFR3 gene. During his first assessment, a karyotype was performed, which also revealed coexistence of KS. He was followed by our pediatric endocrinology team until the age of 16 years, then he was gradually transferred to adult endocrine care.

CONCLUSIONS

This is the first reported case with both conditions that was diagnosed in infancy and was longitudinally followed by a pediatric endocrinology team regularly, from infancy to late adolescence. With a typical phenotype of ACH, it is striking and noteworthy that he did not develop the classical endocrine complications of a child with KS, neither did he necessitate testosterone supplementation during his pubertal development, due to his normal virilization and testosterone levels.

Klinefelter syndrome comorbidities linked to increased X chromosome gene dosage and altered protein interactome activity

Klinefelter syndrome (KS) (47,XXY) is the most common male sex chromosome aneuploidy. Diagnosis and clinical supervision remain a challenge due to varying phenotypic presentation and insufficient characterization of the syndrome. Here we combine health data-driven epidemiology and molecular level systems biology to improve the understanding of KS and the molecular interplay influencing its comorbidities. In total, 78 overrepresented KS comorbidities were identified using in- and out-patient registry data from the entire Danish population covering 6.8 million individuals. The comorbidities extracted included both clinically well-known (e.g. infertility and osteoporosis) and still less established KS comorbidities (e.g. pituitary gland hypofunction and dental caries). Several systems biology approaches were applied to identify key molecular players underlying KS comorbidities: Identification of co-expressed modules as well as central hubs and gene dosage perturbed protein complexes in a KS comorbidity network build from known disease proteins and their protein–protein interactions. The systems biology approaches together pointed to novel aspects of KS disease phenotypes including perturbed Jak-STAT pathway, dysregulated genes important for disturbed immune system (IL4), energy balance (POMC and LEP) and erythropoietin signalling in KS. We present an extended epidemiological study that links KS comorbidities to the molecular level and identify potential causal players in the disease biology underlying the identified comorbidities.

Klinefelter syndrome (KS): genetics, clinical phenotype and hypogonadism

Klinefelter Syndrome (KS) is characterized by an extreme heterogeneity in its clinical and genetic presentation. The relationship between clinical phenotype and genetic background has been partially disclosed; nevertheless, physicians are aware that several aspects concerning this issue are far to be fully understood. By improving our knowledge on the role of some genetic aspects as well as on the KS, patients' interindividual differences in terms of health status will result in a better management of this chromosomal disease. The aim of this review is to provide an update on both genetic and clinical phenotype and their interrelationships.

Thrombophilia in Klinefelter Syndrome With Deep Venous Thrombosis, Pulmonary Embolism, and Mesenteric Artery Thrombosis on Testosterone Therapy: A Pilot Study

We compared thrombophilia and hypofibrinolysis in 6 men with Klinefelter syndrome (KS), without previously known familial thrombophilia, who had sustained deep venous thrombosis (DVT)-pulmonary emboli (PE) or mesenteric artery thrombosis on testosterone replacement therapy (TRT). After the diagnosis of KS, TRT had been started in the 6 men at ages 11, 12, 13, 13, 19, and 48 years. After starting TRT, DVT-PE or mesenteric artery thrombosis was developed in 6 months, 1, 11, 11, 12, and 49 years. Of the 6 men, 4 had high (>150%) factor VIII (177%, 192%, 263%, and 293%), 3 had high (>150%) factor XI (165%, 181%, and 193%), 1 was heterozygous for the factor V Leiden mutation, and 1 was heterozygous for the G20210A prothrombin gene mutation. None of the 6 men had a precipitating event before their DVT-PE. We speculate that the previously known increased rate of DVT-PE and other thrombi in KS reflects an interaction between prothrombotic, long-term TRT with previously undiagnosed familial thrombophilia. Thrombophilia screening in men with KS before starting TRT would identify a cohort at increased risk for subsequent DVT-PE, providing an optimally informed estimate of the risk/benefit ratio of TRT.

Testicular function during puberty and young adulthood in patients with Klinefelter's syndrome with and without spermatozoa in seminal fluid

Patients with Klinefelter's syndrome experience progressive testicular degeneration resulting in impaired endocrine function and azoospermia. What proportion of adolescents develop testosterone deficiency during puberty and how many have spermatozoa in their semen is unclear to date. We aimed to investigate testicular function during puberty and young adulthood in patients with Klinefelter's syndrome and to assess testosterone effects in target tissues. The clinical data of 281 patients with non-mosaic Klinefelter's syndrome aged 10-25 years without previous testosterone replacement were reviewed. In late pubertal adolescents, semen analyses were evaluated, and testicular volumes, hormone and haemoglobin (Hb) levels, the number of CAG repeats and final height data were compared to those of 233 age-matched controls with pubertal gynaecomastia. Spontaneous pubertal virilisation to Tanner stages IV-V occurred. Serum T levels ≥10 nmol/L were reached in 62% of patients with Klinefelter's syndrome and in 85% of controls at ages 15-25 (T_KFS : 12.2 ± 5.4 vs. T_C : 16.6 ± 7.2 nmol/L). LH_KFS levels were elevated >10 U/L in 84%, and normal in all controls (LH_KFS : 18.6 ± 12.2 vs. LH_C : 3.5 ± 1.6 U/L). In nine of 130 (7%) adolescents with Klinefelter's syndrome, spermatozoa (oligozoospermia) were found in semen; all had T levels >7 nmol/L and eight of nine had LH levels ≤18 U/L, while their hormone levels, number of CAG repeats and testicular volumes were not different from those of adolescents with azoospermia. Controls had normal sperm concentrations in 73% (46/63). Semen volumes_KFS were normal in 55% vs. 78% in controls; Hb_KFS was normal in 89% (Hb_C : 97%). Mean final height_KFS was 185 ± 8 cm vs. 181 ± 7 cm in controls. Hypergonadotropic hypogonadism develops during early puberty in adolescents with Klinefelter's syndrome and remains compensated in over 60% during ages 15-25, with sufficient testosterone secretion for spontaneous accomplishment of pubertal development. Spermatozoa in semen are rare and associated with T levels >7 nmol/L. Parameters reflecting androgen deficiency in target tissues may help to optimise timing of testosterone substitution, which should preferably not be initiated before fertility status has been clarified.

Human chorionic gonadotropin stimulation gives evidence of differences in testicular steroidogenesis in Klinefelter syndrome, as assessed by liquid chromatography-tandem mass spectrometry

BACKGROUND

Men with Klinefelter syndrome (KS) show hypergonadotropic hypogonadism, but the pathogenesis of hypotestosteronemia remains unclear. Testicular steroidogenesis in KS men was evaluated over three decades ago after human chorionic gonadotropin (hCG) stimulation, but inconclusive results were obtained. Intriguingly, some recent studies show increased intratesticular testosterone concentrations in men with KS.

OBJECTIVE

To analyze serum steroid profile, as a proxy of testicular steroidogenesis, after hCG stimulation in KS compared with control men.

DESIGN

A prospective, longitudinal, case-control, clinical trial.

METHODS

Thirteen KS patients (36±9 years) not receiving testosterone (TS) replacement therapy and 12 eugonadic controls (32±8 years) were enrolled. Serum steroids were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) at baseline and for five consecutive days after intramuscular injection of 5000IU hCG.

RESULTS

Progesterone (P), 17-hydroxyprogesterone (17OHP), TS, and estradiol (E2) showed a significant increase (P<0.001) after hCG stimulation in both groups. On the contrary, androstenedione (AS) and dehydroepiandrosterone did not increase after hCG stimulation. The 17OHP/P ratio increased in both groups (P<0.001), the TS/AS ratio (17β-hydroxysteroid dehydrogenase type 3 (17βHSD3) activity) did not increase after hCG in any group, and the E2/TS ratio (aromatase activity) increased significantly in both groups (P=0.009 in KS and P<0.001 in controls). Luteinizing hormone decreased after hCG in both groups (P=0.014 in KS and P<0.001 in controls), whereas follicle-stimulating hormone decreased only in control men (P<0.001).

CONCLUSION

This study demonstrates for the first time using LC-MS/MS that Leydig cells of KS men are able to respond to hCG stimulation and that the first steps of steroidogenesis are fully functional. However, the TS production in KS men is impaired, possibly related to reduced hydroxysteroid deydrogenase activity due to an unfavorable intratesticular metabolic state.

Klinefelter syndrome has increased brain responses to auditory stimuli and motor output, but not to visual stimuli or Stroop adaptation

Klinefelter syndrome (47, XXY) (KS) is a genetic syndrome characterized by the presence of an extra X chromosome and low level of testosterone, resulting in a number of neurocognitive abnormalities, yet little is known about brain function. This study investigated the fMRI-BOLD response from KS relative to a group of Controls to basic motor, perceptual, executive and adaptation tasks. Participants (N: KS = 49; Controls = 49) responded to whether the words "GREEN" or "RED" were displayed in green or red (incongruent versus congruent colors). One of the colors was presented three times as often as the other, making it possible to study both congruency and adaptation effects independently. Auditory stimuli saying "GREEN" or "RED" had the same distribution, making it possible to study effects of perceptual modality as well as Frequency effects across modalities. We found that KS had an increased response to motor output in primary motor cortex and an increased response to auditory stimuli in auditory cortices, but no difference in primary visual cortices. KS displayed a diminished response to written visual stimuli in secondary visual regions near the Visual Word Form Area, consistent with the widespread dyslexia in the group. No neural differences were found in inhibitory control (Stroop) or in adaptation to differences in stimulus frequencies. Across groups we found a strong positive correlation between age and BOLD response in the brain's motor network with no difference between groups. No effects of testosterone level or brain volume were found. In sum, the present findings suggest that auditory and motor systems in KS are selectively affected, perhaps as a compensatory strategy, and that this is not a systemic effect as it is not seen in the visual system.

DNA methylation signature in peripheral blood reveals distinct characteristics of human X chromosome numerical aberrations

BACKGROUND

Abnormal sex chromosome numbers in humans are observed in Turner (45,X) and Klinefelter (47,XXY) syndromes. Both syndromes are associated with several clinical phenotypes, whose molecular mechanisms are obscure, and show a range of inter-individual penetrance. In order to understand the effect of abnormal numbers of X chromosome on the methylome and its correlation to the variable clinical phenotype, we performed a genome-wide methylation analysis using MeDIP and Illumina's Infinium assay on individuals with four karyotypes: 45,X, 46,XY, 46,XX, and 47,XXY.

RESULTS

DNA methylation changes were widespread on all autosomal chromosomes in 45,X and in 47,XXY individuals, with Turner individuals presenting five times more affected loci. Differentially methylated CpGs, in most cases, have intermediate methylation levels and tend to occur outside CpG islands, especially in individuals with Turner syndrome. The X inactivation process appears to be less effective in Klinefelter syndrome as methylation on the X was decreased compared to normal female samples. In a large number of individuals, we verified several loci by pyrosequencing and observed only weak inter-loci correlations between the verified regions. This suggests a certain stochastic/random contribution to the methylation changes at each locus. Interestingly, methylation patterns on some PAR2 loci differ between male and Turner syndrome individuals and between female and Klinefelter syndrome individuals, which possibly contributed to this distinguished and unique autosomal methylation patterns in Turner and Klinefelter syndrome individuals.

CONCLUSIONS

The presented data clearly show that gain or loss of an X chromosome results in different epigenetic effects, which are not necessary opposite.

Effects of testosterone therapy on bipolar disorder with Klinefelter syndrome

Klinefelter syndrome (KS) is widely associated with cognitive impairment and language problems. KS patients may also exhibit psychiatric symptoms. We present the case of an 18-year-old man with KS who experienced rapidly repeating relapses of manic episodes. He was unresponsive to the usual pharmacotherapies for bipolar disorders such as mood stabilizers and second-generation antipsychotics. Mood was eventually improved with testosterone therapy in addition to pharmacotherapy, with no relapse of manic episodes for 3 years after discharge. Testosterone therapy may prevent relapsing manic episodes of bipolar disorder in patients with KS.