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.

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.

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.

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.

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.

The testicular microvasculature in Klinefelter syndrome is immature with compromised integrity and characterized by excessive inflammatory cross-talk.

STUDY QUESTION: Does Klinefelter syndrome (KS) lead to a distinct gene expression pattern at single-cell level in the testes that could provide insight into the reported microvascular dysfunction in the testes? SUMMARY ANSWER: A distinct gene expression pattern within microvascular-associated cells of males with KS suggests excessive endothelial cell (EC) activation, disorganized vessel formation, and the presence of immature vessels with compromised integrity. WHAT IS KNOWN ALREADY: Recent studies show that males with KS exhibit microvascular dysfunction in their testes, which affects blood flow and is associated with lower circulating levels of testosterone. STUDY DESIGN, SIZE, DURATION: A comparative cross-sectional study of males with KS (n = 6), non-obstructive azoospermia (NOA) (n = 5), cryptozoospermia (n = 3), and controls (n = 15) was carried out. PARTICIPANTS/MATERIALS, SETTING, METHODS: We analyzed publicly available single-cell RNA sequencing data of testicular cells from males with KS, males with NOA, males with cryptozoospermia, and controls. The integration of these datasets allowed us to analyze gene expression profiles and communication patterns among the cell types within the testis and to identify capillary ECs to investigate changes at the microvascular level. MAIN RESULTS AND THE ROLE OF CHANCE: Rooted in changes at the single-cell level, our study demonstrates a shift in gene expression forming the foundation for altered cellular communication, microvascular remodeling, and pro-inflammatory responses within the testes of males with KS. We identified genes that were dysregulated in capillary ECs from males with KS (Padj < 0.05). Specifically, the unique microvascular gene expression in males with KS indicated enhanced capillary EC activation and increased inflammatory cross-talk, leading to impaired vessel maturation and increased EC barrier permeability. LIMITATIONS, REASONS FOR CAUTION: Our study is constrained by an unbalanced design, with varying sample sizes and number of cells within each group. We acknowledge the restricted access to clinical information. In addition, our findings were deduced from changes in gene expression, which limits us to infer potential biological consequences arising from these alterations. Furthermore, the absence of a pre-pubertal age group limits the generalizability of our findings and warrants further investigation. WIDER IMPLICATIONS OF THE FINDINGS: This study offers novel insights into the testicular pathophysiology in KS and underscores the potential contribution of microvascular dysfunction to the hypogonadism and infertility observed in males with KS. While this study aims to better understand the microvascular dysfunction in KS, the precise connections to testosterone deficiency and testicular atrophy remain to be fully elucidated. STUDY FUNDING/COMPETING INTEREST(S): A.S. was supported by the Independent Research Fund Denmark (0134-00130B). C.H.G. was supported by Novo Nordisk Foundation (NNF15OC0016474, NNF20OC0060610), 'Fonden til lægevidenskabens fremme', the Familien Hede Nielsen foundation and the Independent Research Fund Denmark (0134-00406A). E.B.J. was supported by Aarhus University and E.B.J. and C.H.G by the Independent Research Fund Denmark (2096-00165A). J.M.K. was supported by Lundbeckfonden (R307-2018-3667), Carlsberg Fonden (CF19-0687), Novo Nordisk Fonden (0073440) and Steno Diabetes Center Aarhus (SDCA). The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Leydig cell metabolic disorder act as a new mechanism affecting for focal spermatogenesis in Klinefelter syndrome patients: a real world cross-sectional study base on the age.

Background: Klinefelter's syndrome (KS) was once considered infertile due to congenital chromosomal abnormalities, but the presence of focal spermatozoa changed this. The key to predict and promote spermatogenesis is to find targets that regulate focal spermatogenesis. Objective: To explore the trend of fertility changes in KS patients at different ages and identify potential therapeutic targets. Methods: Bibliometric analysis was used to collect clinical research data on KS from the Web of Science Core Collection (WoSCC) from 1992 to 2022. A cross-sectional study was conducted on 75 KS patients who underwent microscopic testicular sperm extraction (mTESE) from 2017 to 2022 in the real world. The reproductive hormones, testicular histopathology, androgen receptors, insulin-like factor 3 (INSL3) receptors and sperm recovery rate (SRR) were analyzed. Results: Male infertility, dysplasia, Sertoli cells, Leydig cells, testosterone and spermatogenesis were the research focuses related to KS. Luteinizing hormone (LH), testosterone, and INSL3 were evaluation indicators of Leydig cell function that fluctuate with age. Testosterone and LH peaked at ages 13-19 and 30-45, while INSL3 only peaked at ages 13-19. 27 patients (27/75) recovered sperm through mTESE and experienced SRR peaks at the ages of 20, 28, 34, and 37. The SRR of fibrosis patients was 46.15%, fatty degeneration was 7.14%, and melanosis was 40.00%. The INSL3 and androgen receptors were highly expressed and roughly balanced in focal spermatogenesis. Conclusion: Abnormal metabolism of Leydig cells led to imbalanced expression of INSL3 and androgen receptors, which might be a potential target for spermatogenesis in KS.

Executive Dysfunction in Klinefelter Syndrome: Associations With Brain Activation and Testicular Failure.

CONTEXT: Executive dysfunction is a well-recognized component of the cognitive phenotype of Klinefelter syndrome (KS), yet the neural basis of KS-associated cognitive weaknesses, and their association with testicular failure is unknown. OBJECTIVE: We investigated executive function, brain activation, and pubertal development in adolescents with and without KS. METHODS: Forty-three adolescents with KS (mean age 12.3 ± 2.3 years) and 41 typically developing boys (mean age 11.9 ± 1.8 years) underwent pubertal evaluation, behavioral assessment, and completed functional magnetic resonance imaging (fMRI) as they performed an executive function task, the go/no-go task. Group differences in activation were examined. Associations among activation, executive function, and pubertal development measures were tested in secondary analyses. RESULTS: Boys with KS exhibited reduced executive function, as well as lower activation in brain regions subserving executive function, including the inferior frontal gyrus, anterior insula, dorsal anterior cingulate cortex, and caudate nucleus. Secondary analyses indicated that the magnitude of activation differences in boys with KS was associated with severity of pubertal developmental delay, as indexed by lower testosterone (t(36) = 2.285; P = .028) and lower testes volume (t(36) = 2.238; P = .031). Greater parent-reported attention difficulties were additionally associated with lower testicular volume (t(36) = -2.028; P = .050). CONCLUSION: These findings indicate a neural basis for executive dysfunction in KS and suggest alterations in pubertal development may contribute to increased severity of this cognitive weakness. Future studies that examine whether these patterns change with testosterone replacement therapy are warranted.

The Effect of Hormonal Therapy on the Behavioral Outcomes in 47,XXY (Klinefelter Syndrome) between 7 and 12 Years of Age.

47,XXY, also known as Klinefelter syndrome, is the most commonly occurring sex chromosomal aneuploidy (SCA). Hormonal replacement therapy (HRT) has been associated with improved neurodevelopmental capabilities in boys with 47,XXY, although studies investigating HRT's possible positive effect on behavioral outcomes are scarce. This study explores the association between behavioral outcomes and HRT in boys ages 7-12. Patients were divided into 4 groups based on HRT status: untreated, early hormonal treatment (EHT), hormonal booster therapy (HBT), and both EHT and HBT. Analysis of Variance (ANOVA) and Kruskal-Wallis tests were conducted to determine group differences on the Child Behavior Checklist (CBCL) and the Behavior Rating Inventory of Executive Function (BRIEF). The treated groups were found to have better scores in emotional control, initiative, organization of materials, behavioral rating index, metacognition index, and global executive composite than the untreated group on the BRIEF. On the CBCL, the treated groups presented better scores for somatic complaints, social problems, thought problems, attention problems, aggressive behavior, internalizing problems, total problems, affective problems, somatic problems, ADHD problems, oppositional defiant problems, and sluggish problems in comparison to the untreated group. These results offer evidence that HRT, specifically the combination of both EHT and HBT, may be successful in mitigating some undesirable behavioral outcomes. Further research is necessary to determine the efficacy of the combination of EHT and HBT regarding dosage, specific ages, and long-term benefits.

The First Case Report of 47,XXY/46,XX/46,XY Mosaic Klinefelter Syndrome Patient With Mixed Connective Tissue Disorder.

Klinefelter syndrome (KS) mosaicism 47,XXY/46,XX/46,XY is an extremely rare disorder. Mixed connective tissue disorder (MCTD) is a systemic rheumatological disease with overlapping characteristic features of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), polymyositis (PM)/dermatomyositis (DM), and rheumatoid arthritis (RA). It contains a higher titer level of U1-RNP and anti-RNP antibodies. A 50-year-old man was referred to our clinic with gynecomastia, lower extremity rash, persistent fever, arthralgia, muscle weakness, dry eye and mouth, Raynaud's phenomenon abnormal, and hormone levels. He was a follow-up patient for MCTD. Chromosome analysis of the patient revealed an abnormal karyotype of mos47,XXY/46,XX/46,XY. Fluorescence in situ hybridization (FISH) analysis indicated ish(SRYx1),(DZYx1)(DZX1x2)/ish (SRYx0),(DYZ1x0)(DZX1x2)/ish(SRYx1), (DZYx1)(DZX1x1). Although the prevalence of autoimmune diseases in Klinefelter syndrome is unknown, it is thought that the estimated frequency is higher than men, close levels to that of women. This might be explained by several genes that regulate the function of the immune system located on the X chromosome and the gene dosage mechanism that is the escape of X-inactivation in early embryogenesis for KS development. To the best of our knowledge, this is the first case to report a 47,XXY/46,XX/46,XY Klinefelter syndrome patient with MCTD.

Individuals with numerical and structural variations of sex chromosomes: interdisciplinary management with focus on fertility potential.

Diagnosis and management of individuals who have differences of sex development (DSD) due to numerical or structural variations of sex chromosomes (NSVSC) remains challenging. Girls who have Turner syndrome (45X) may present with varying phenotypic features, from classical/severe to minor, and some remain undiagnosed. Boys and girls who have 45,X/46,XY chromosomal mosaicism may have Turner syndrome-like features and short stature; therefore, unexplained short stature during childhood requires karyotype analysis in both sexes, particularly if characteristic features or atypical genitalia are present. Many individuals with Klinefelter syndrome (47XXY) remain undiagnosed or are only diagnosed as adults due to fertility problems. Newborn screening by heel prick tests could potentially identify sex chromosome variations but would have ethical and financial implications, and in-depth cost-benefit analyses are needed before nationwide screening can be introduced. Most individuals who have NSVSC have lifelong co-morbidities and healthcare should be holistic, personalized and centralized, with a focus on information, psychosocial support and shared decision-making. Fertility potential should be assessed individually and discussed at an appropriate age. Oocyte or ovarian tissue cryopreservation is possible in some women who have Turner syndrome and live births have been reported following assisted reproductive technology (ART). Testicular sperm cell extraction (TESE) is possible in some men who have 45,X/46,XY mosaicism, but there is no established protocol and no reported fathering of children. Some men with Klinefelter syndrome can now father a child following TESE and ART, with multiple reports of healthy live births. Children who have NSVSC, their parents and DSD team members need to address possibilities and ethical questions relating to potential fertility preservation, with guidelines and international studies still needed.

Hypergonadotropic hypogonadism and chromosomal aberrations: clinical heterogeneity and implications on the health of elderly men, case series.

BACKGROUND: Hypogonadism in older men is often considered as late onset hypogonadism. However, this clinical condition results from primary testicular failure which could be of genetic origin with Klinefelter syndrome being the most common chromosomal abnormality associated with it. CASE PRESENTATION: We report a heterogeneous group of cases who were diagnosed with hypergonadotropic hypogonadism in their adulthood and were found to have rare chromosomal aberrations. All were elderly men (in their 70 s and 80 s) for whom the diagnosis was made during the evaluation of incidental symptoms suggestive of endocrinopathy. The first had hyponatremia; the other two had gynaecomastia and features of hypogonadism noted during admission for various acute medical problems. With respect to their genetic results; the first had a male karyotype with balanced reciprocal translocation between the long arm of chromosome 4 and the short arm of chromosome 7. The second case had a male karotype with one normal X chromosome and an isochrome for the short arm of the Y chromosome. The third case was an XX male with unbalanced translocation between the X & Y chromosomes with retention of the SRY locus. CONCLUSION: Hypergonadotrophic hypogonadism in the elderly, may be due to chromosomal aberrations, resulting in heterogeneous and diverse clinical phenotypes. Vigilance must be exercised when seeing cases with subtle clinical findings. This report suggests that in selected cases of adult hypergonadotropic hypogonadism, chromosomal analysis may be indicated.

Low XIST expression in Sertoli cells of Klinefelter syndrome patients causes high susceptibility of these cells to an extra X chromosome.

Klinefelter syndrome (KS) is the most common genetic cause of human male infertility. However, the effect of the extra X chromosome on different testicular cell types remains poorly understood. Here, we profiled testicular single-cell transcriptomes from three KS patients and normal karyotype control individuals. Among the different somatic cells, Sertoli cells showed the greatest transcriptome changes in KS patients. Further analysis showed that X-inactive-specific transcript ( XIST ), a key factor that inactivates one X chromosome in female mammals, was widely expressed in each testicular somatic cell type but not in Sertoli cells. The loss of XIST in Sertoli cells leads to an increased level of X chromosome genes, and further disrupts their transcription pattern and cellular function. This phenomenon was not detected in other somatic cells such as Leydig cells and vascular endothelial cells. These results proposed a new mechanism to explain why testicular atrophy in KS patients is heterogeneous with loss of seminiferous tubules but interstitial hyperplasia. Our study provides a theoretical basis for subsequent research and related treatment of KS by identifying Sertoli cell-specific X chromosome inactivation failure.

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.

Concomitance of 47,XXY, a balanced reciprocal translocation of t(4;17)(q12;q11.2) encompassing SPINK2 at 4q12 and NOS at 17q11.2 and an AZFa sY86 deletion in an infertile male.

OBJECTIVE: We present an infertile male who was incidentally detected to have Klinefelter syndrome, a balanced reciprocal translocation of t(4; 17) (q12; q11.2) and an AZFa sY86 deletion. We review the literature and discuss the significance of 47,XXY, t(4; 17) (q12; q11.2) and AZFa sY86 deletion in this case. CASE REPORT: A 37-year-old married infertile male was referred for genetic studies of azoospermia. His height was 195 cm and his weight was 85 kg. He had been married for more than one year without any pregnancy in his wife. He was referred for genetic counseling. Cytogenetic analysis revealed a karyotype of 47,XXY,t(4; 17) (q12; q11.2). In addition to Klinefelter syndrome, a balanced reciprocal translocation and an AZFa microdeletion were found. Sequence analysis of SPINK2 and NOS was also performed. These two fertile related genes were located at the breakpoints of translocation respectively. Heterozygosity of single-nucleotide polymorphisms (SNPs) evidenced the presence of two alleles as well as no deletions occurred at the breakpoint regions. An AZF gene analysis revealed a microdeletion at the region of AZFa sY86 region. CONCLUSION: Genetic analysis of an infertile male may detect multiple factors associated with azoospermia such as translocation, an AZF deletion and Klinefelter syndrome. This case emphasized the importance of tests for chromosomes and AZF deletions among patients with azoospermia. Complete genetic counseling of the consequence of a familial inheritance is also necessary to detect more family carrier members for the prevention of unbalanced chromosome in the offspring.

Combined Alport syndrome, Klinefelter syndrome and Fanconi syndrome in a Chinese boy.

Alport syndrome (AS) is a progressive renal disease characterized by hematuria and progressive renal failure. X-linked dominant (XLAS) is the major inheritance form, accounting for almost 80% of the cases, caused by mutations in COL4A5 genes. Klinefelter syndrome (KS) is the most common genetic cause of human male gonadal dysgenesis. AS and KS are both rare disease, there are only three cases of combined AS and KS in the literatures. Fanconi syndrome (FS) caused by AS is also very rare. We report here the first case combined AS, KS and FS in a Chinese boy. We suggest that the severe renal phenotype and FS might be due to the two homozygous COL4A5 variants in our boy, and cases of AS combined KS will be good research objects for X chromosome inactivation.

Testicular Architecture of Men with 46,XX Testicular Disorders of Sex Development.

BACKGROUND: A subtype of disorders of sex development (DSD) in individuals with a 46,XX karyotype who are phenotypically male is classified as testicular DSD (46,XX TDSD). These individuals develop testes but are infertile due to germ cell loss. However, little is known about their testicular architecture. METHODS: We analyzed biopsies of four SRY positive 46,XX TDSD men for testicular architecture, Sertoli (SCs) and Leydig cells (LCs). These were compared with biopsies of men with normal spermatogenesis (NS, n = 4), men with Klinefelter syndrome, 47 XXY (KS, n = 4), and men with AZF deletions (AZF, n = 5). Testicular architecture was evaluated and SCs and LCs were analyzed for specific markers (SC: SOX9, DMRT1; LC: INSL3). RESULTS: A smaller number of tubules, more SOX9-negative but similar proportions of DMRT1-negative SCs were found in 46,XX TDSD compared to NS. The lower number of tubules and severe LC hyperplasia observed in 46,XX TDSD were similar to KS. CONCLUSION: Testicular architecture and marker expression of SCs and LCs in 46,XX TDSD men display unique patterns, which are discernable from chromosomal aneuploidies. Given the reduced Y-chromosomal gene content in 46,XX TDSD, the supernumerary X chromosome effects may be decisive regarding the damage on testicular composition and endocrine function.

State-wide increase in prenatal diagnosis of klinefelter syndrome on amniocentesis and chorionic villus sampling: Impact of non-invasive prenatal testing for sex chromosome conditions.

BACKGROUND: To analyze population-based trends in the prenatal diagnosis of sex chromosome aneuploidy (SCA) since the availability of non-invasive prenatal testing (NIPT). METHODS: Retrospective state-wide data for all prenatal diagnoses performed <25 weeks gestation from 2005 to 2020 in Victoria, Australia. Non-invasive prenatal testing became locally available from 2012. The prenatal diagnosis rates of SCA as proportions of all prenatal diagnostic tests and all births were calculated. Statistical significance was assessed with the χ2 test for trend, with p < 0.05 considered significant. RESULTS: 46,518 amniocentesis and chorionic villus sampling were performed during the study period, detecting 617 SCAs. There was a significant increase in the rate of prenatal SCAs from 5.8 per 10,000 births in 2005 to 8.7 per 10,000 births in 2020 (p < 0.0001). This increase was predominantly due to 47,XXY cases, 91% of which were ascertained via positive NIPT for this condition in 2020. The prenatal diagnosis rate of 47,XXY significantly increased from 0.8 per 10,000 births in 2005 to 4.3 per 10,000 births in 2020 (p < 0.0001). CONCLUSION: Screening for SCAs using NIPT has directly led to an increase in their prenatal diagnosis on a population-wide basis, especially 47,XXY. This has implications for clinician education, genetic counselling, and pediatric services.