Endocrine and metabolic evaluation of classic Klinefelter syndrome and high-grade aneuploidies of sexual chromosomes with male phenotype: are they different clinical conditions?

Unexplained Loss of Consciousness in a Patient With Klinefelter Syndrome and Brugada Syndrome

Managing patients with both Klinefelter syndrome (KS) and Brugada syndrome (BrS) is challenging because of the rarity of this unique interaction. A man diagnosed with KS during fertility treatment experienced chronic muscle pain, severe depression, and cognitive difficulties, managed with testosterone therapy and antidepressants. Increased testosterone doses led to recurrent episodes of loss of consciousness, initially considered epileptic. Hormonal assessments, cardiac imaging, Holter monitoring, electrophysiological studies, and genetic testing led to BrS diagnosis. A positive ventricular tachycardia stimulation study led to the implantation of an implantable cardioverter-defibrillator. Following implantable cardioverter-defibrillator insertion, discontinuing testosterone, and changing medication, the patient has remained stable. The coexistence of KS and BrS is extremely rare. Understanding hormonal and genetic interactions in managing such complex cases is crucial.

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

OBJECTIVE

High-grade aneuploidies of X and Y sex chromosomes (HGAs) are exceedingly rare and complex conditions. We aimed to investigate the effect of supernumerary X chromosomes (extra-Xs) on the clinical, hormonal, metabolic, and echocardiographic features of patients with HGAs.

DESIGN AND METHODS

In a cross-sectional study, we compared 23 subjects with HGAs and 46 age-matched subjects with 47,XXY Klinefelter syndrome (KS), according to the number of extra-Xs: two (47,XXY and 48,XXYY), three (48,XXXY and 49,XXXYY), or four supernumerary Xs (49,XXXXY). A second cohort consisting of 46 pubertal stage-matched KS subjects was employed for validation. Clinical, hormonal, metabolic and ultrasonographic parameters were collected and analyzed.

RESULTS

The increase in the number of extra-Xs was associated with a progressive adverse effect on height, pubertal development, testicular volume and function, adrenal steroidogenesis, and thyroid function. A progressive linear increase in ACTH and a decrease in cortisol/ACTH ratios were found. Weight and body mass index, Sertoli cell function, lipid profile, and glucose tolerance post-oral glucose tolerance test were all worse in the HGA cohort compared to KS. Cardiac evaluation revealed a linear association with reduced left and right end-diastolic diameters and reduced ejection fraction.

CONCLUSION

The increase in the number of extra-Xs is associated with a "dose-dependent" progressive impairment in steroid producing glands, thyroid function, cardiac structure, and performance.

Klinefelter Syndrome: A Genetic Disorder Leading to Neuroendocrine Modifications and Psychopathological Vulnerabilities in Children-A Literature Review and Case Report

Klinefelter syndrome (KS), characterized by an additional X-chromosome in males, manifests in a wide range of neuroendocrine and psychiatric symptoms. Individuals with KS often face increased risks of hormonal dysfunction, leading to depression and anxiety, although extended research during pediatric and adolescent age is still limited. This critical phase, decisive for KS children, is influenced by a combination of genetic, environmental and familial factors, which impact brain plasticity. In this report, we reviewed, in a narrative form, the crucial KS psychopathological hallmarks in children. To better describe neuroendocrine and neuropsychiatric outcomes in children with KS, we presented the case of an 11-year-old prepubertal child with mosaic KS who was referred to our Center of Developmental Psychopathology due to a decline in his academic performance, excessive daytime fatigue and increased distractibility over the past few months. Family history revealed psychiatric conditions among first- and second-degree relatives, including recently divorced parents and a 15-year-old sister. Early-onset persistent depressive disorder and anxious traits were diagnosed. Timely identification of susceptible children, with thorough examination of familial psychiatric history, environmental influences and neurocognitive profile, alongside targeted interventions, could potentially mitigate lifelong psychopathology-related disabilities in pediatric and adolescent KS cases, including those with mosaic KS.

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.

NGF and BDNF in pediatrics syndromes

Neurotrophins (NTs) as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) play multiple roles in different settings including neuronal development, function and survival in both the peripheral and the central nervous systems from early stages. This report aims to provide a summary and subsequent review of evidences on the role of NTs in rare and non-common pediatric human diseases associated with changes in neurodevelopment. A variety of diseases has been analyzed and many have been linked to NTs neurobiological effects, including chronic granulomatous disease, hereditary sensory and autonomic neuropathy, Duchenne muscular dystrophy, Bardet-Biedl syndrome, Angelman syndrome, fragile X syndrome, trisomy 16, Williams-Beuren syndrome, Prader-Willi syndrome, WAGR syndrome, fetal alcohol spectrum disorders, Down syndrome and Klinefelter Syndrome. NTs alterations have been associated with numerous pathologic manifestations including cognitive defects, behavioral abnormalities, epilepsy, obesity, tumorigenesis as well as muscle-skeletal, immunity, bowel, pain sensibility and cilia diseases. In this report, we discuss that further studies are needed to clear a possible therapeutic role of NTs in these still often uncurable diseases.

Clinical, Cognitive and Neurodevelopmental Profile in Tetrasomies and Pentasomies: A Systematic Review

Background: Sex chromosome aneuploidies (SCAs) are a group of disorders characterised by an abnormal number of sex chromosomes. Collective prevalence rate of SCAs is estimated to be around 1 in 400-500 live births; sex chromosome trisomies (e.g., XXX, XXY, XYY) are most frequent, while tetra- and pentasomies (e.g., XXXX, XXXXX, XXXY, XXXXY) are rarer, and the most common is 48, XXYY syndrome. The presence of additional X and/or Y chromosomes is believed to cause neurodevelopmental differences, with increased risk for developmental delays, language-based learning disabilities, cognitive impairments, executive dysfunction, and behavioural and psychological disorders. Aim of the Study: Our review has the purpose of analysing the neurocognitive, linguistical and behavioural profile of patients affected by sex chromosomes supernumerary aneuploidies (tetrasomy and pentasomy) to better understand the specific areas of weakness, in order to provide specific rehabilitation therapy. Methods: The literature search was performed by two authors independently. We used MEDLINE, PubMed, and PsycINFO search engines to identify sources of interest, without year or language restrictions. At the end of an accurate selection, 16 articles fulfilled the inclusion and exclusion criteria. Results and Conclusions: International literature has described single aspects of the neuropsychological profile of 48, XXYY and 49, XXXXY patients. In 48, XXYY patients, various degrees of psychosocial/executive functioning issues have been reported and there is an increased frequency of behavioural problems in childhood. Developmental delay and behavioural problems are the most common presenting problems, even if anxiety, depression and oppositional defiant disorder are also reported. They also show generalized difficulties with socialization and communication. Cognitive abilities are lower in measures of verbal IQ than in measures of performance IQ. Visuospatial skills are a relative strength compared to verbal skills. In patients with 49, XXXXY, both intellectual and adaptive functioning skills fall into the disability range, with better non-verbal cognitive performance. Speech and language testing reveals more deficits in expressive language than receptive language and comprehension. Anxiety, thought problems, internalizing and externalizing problems, and deficits in social cognition and communication are reported. Behavioural symptoms lessen from school age to adolescence, with the exception of thought problems and anxiety. Individuals affected by sex chromosome aneuploidies show testosterone deficiency, microorchidism, lack of pubertal progression and infertility. Hormone replacement therapy (HRT) is usually recommended for these patients: different studies have found that testosterone-based HRT benefit a wide range of areas initiated in these disorders, affecting not only neuromotor, cognitive and behavioural profile but also structural anomalies of the brain (i.e., increase of volume of grey temporal lobe matter). In conclusion, further studies are needed to better understand the neuropsychological profile with a complete evaluation, including neurocognitive and psychosocial aspects and to establish the real impact of HRT on improving the cognitive and behavioural profile of these patients.

Prokineticin 2/PROK2 and Male Infertility

Male infertility represents about 50% of the causes of infertility in couples. The diagnosis process represents an important procedure for defining, when possible, the causes and approaching treatments (pharmacological, surgical) aimed at overcoming the problem. Several scientific studies have set out to discover early and indicative markers capable of providing information on the biological origin of infertility and increase current knowledge in the context of new potential therapeutic approaches. The prokineticin system (PROK) consists of the prokineticin 1 (PROK1) and prokineticin 2 (PROK2) proteins. Through the activation of two G-protein receptors (PROKR1 and PROKR2) regulate a wide range of biological functions, including gastrointestinal motility, circadian rhythm regulation, neurogenesis, angiogenesis, pain perception, and mood regulation. Several studies have highlighted the crucial role of the PROK system in the development and maturation of both male and female human reproductive organs. Particularly in men, the PROK system represents a new system useful to clarify some aspects of testicular pathophysiology and provide new potential hypotheses for therapeutic intervention. This narrative review aims to illustrate the state of the art regarding, in particular, the role of PROK2 in male infertility.

Serum Prokineticin-2 in Prepubertal and Adult Klinefelter Individuals

The prokineticin-2 (PROK2) is a small peptide belonging to the prokineticin family. In humans and rodents this chemokine is primarily involved in the control of central and peripheral reproductive processes. Klinefelter's syndrome (KS) is the first cause of male genetic infertility, due to an extra X chromosome, which may occur with a classical karyotype (47, XXY) or mosaic forms (46, XY/47, XXY). In affected subjects, pubertal maturation usually begins at an adequate chronological age, but when development is almost complete, they display a primary gonadal failure, with early spermatogenesis damage, and later onset of testosterone insufficiency. Thus, the main aim of the present study was to investigate the serum levels of PROK2 in prepubertal and adult KS patients, comparing them with healthy subjects. We showed for the first time the presence of PROK2 in the children serum but with significant changes in KS individuals. Indeed, compared to healthy subjects characterized by PROK2 serum elevation during the growth, KS individuals showed constant serum levels during the sexual maturation phase (higher during the prepubertal phase but lower during the adult age). In conclusion, these data indicate that in KS individuals PROK2 may be considered a biomarker for investigating the SK infertility process.

Adverse pathophysiological influence of early testosterone therapy on the testes of boys with higher grade sex chromosome aneuploidies (HGAs): a retrospective, cross-sectional study

PURPOSE

Higher grade aneuploidies (HGAs) of the male sex chromosomes are a rare genetic group of pathologies caused by nondisjunction meiotic events. The aim of this study was to evaluate the impact of early androgenic therapy on the testicular secretory hormone profile, and the pathophysiological implications.

PATIENTS AND METHODS

In this cross-sectional study, 18 HGA subjects aged 6-8 years were recruited. They were divided into two groups, based on whether or not they had previously undergone testosterone therapy (group 1: 11 untreated subjects; group 2: 7 treated subjects). Serum FSH, LH, testosterone (T), inhibin B (INHB) and anti-Müllerian hormone (AMH) were determined, and auxological parameters were assessed. Five group 1 patients and four group 2 patients were treated with hCG (human chorionic gonadotropin) for inguinal cryptorchidism; their hormone profile and auxological parameters were assessed both pre- and post-hCG treatment.

RESULTS

Group 1 subjects showed significantly higher testicular volume and higher levels of AMH and INHB (p < 0.0001). Subjects who had undergone hCG therapy showed a significantly higher testicular volume, penis length (respectively, p = 0.008 and p = 0.0005 for group 1 and p = 0.04 and p = 0.001 for group 2) and T (p = 0.005 for group 1 and p = 0.004 for group 2).

CONCLUSIONS

HGA patients undergoing early testosterone therapy show an earlier and persistent suppression of testicular secretory function. At this age, the testes are still responsive to stimulation with hCG. The selection of patients to be treated must be accompanied by a thorough clinical and hormonal evaluation.

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

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

Central hypogonadism in Klinefelter syndrome: report of two cases and review of the literature

PURPOSE

Klinefelter syndrome (KS) is characterized by late adolescence/young adulthood onset of primary hypogonadism. Hypogonadotropic hypogonadism (HH), when congenital, is usually associated with absent/incomplete puberty and low/normal gonadotropins. We report the clinical and genetic features of two subjects with KS and an unexpected HH hormone profile.

METHODS

Magnetic resonance imaging (MRI) of hypothalamus-pituitary region and next generation sequencing (NGS) of congenital HH-associated genes were obtained. A narrative review of the literature was conducted.

RESULTS

Patients were diagnosed with Klinefelter syndrome following karyotype analysis. Nevertheless, they showed unusual features: both had incomplete puberty, low gonadotropins and testosterone levels, and the first one was anosmic. Sellar lesions were excluded by MRI, and NGS was negative in both subjects. Our data add to those of the only 14 similar cases reported so far. Unexplained HH rarely occurs in KS and is variably associated with anosmia, other pituitary hormones deficiencies and heterogeneous karyotypes. However, most cases show an early, pre-pubertal onset of hypogonadism. If the causes behind this gonadotropins defect are largely unknown, hereby we provide the first review of the literature on this topic and propose some pathogenetic hypotheses, including the coexistence of KS and congenital HH as suggested by overlapping clinical features in some of these patients.

CONCLUSION

HH is an exceptional occurrence in Klinefelter syndrome and is associated with heterogeneous phenotypes and, probably, aetiologies. Moreover, KS could underlie HH nonresponsive to gonadotropins. An exhaustive diagnostic workup and a tailored clinical management are advisable in these rare forms.

From mini-puberty to pre-puberty: early impairment of the hypothalamus-pituitary-gonadal axis with normal testicular function in children with non-mosaic Klinefelter syndrome

PURPOSE

Klinefelter syndrome (KS) is a genetic disorder caused by the presence of an extra X chromosome in males. The aim of this study was to evaluate the hypothalamic-pituitary-gonadal (HPG) axis and the clinical profile of KS boys from mini-puberty to early childhood.

PATIENTS AND METHODS

In this retrospective, cross-sectional, population study, 145 KS boys and 97 controls aged 0-11.9 years were recruited. Serum FSH, LH, testosterone (T), Inhibin B (INHB), sex hormone binding globulin (SHBG) and anti-Müllerian hormone (AMH) were determined. Auxological parameters were assessed. To better represent the hormonal and clinical changes that appear in childhood, the entire population was divided into 3 groups: ≤ 6 months (group 1; mini-puberty); > 6 months and ≤ 8 years (group 2; early childhood); > 8 and ≤ 12 years (group 3; mid childhood).

RESULTS

During mini-puberty (group 1), FSH and LH were significantly higher in KS infants than controls (p < 0.05), as were INHB and T (respectively p < 0.0001 and p < 0.005). INHB was also significantly higher in KS than controls in group 2 (p < 0.05). AMH appeared higher in KS than in controls in all groups, but the difference was only statistically significant in group 2 (p < 0.05). No significant differences were found in height, weight, testicular volume, and penile length.

CONCLUSIONS

No hormonal signs of tubular or interstitial damage were found in KS infants. The presence of higher levels of gonadotropins, INHB and testosterone during mini-puberty and pre-puberty may be interpreted as an alteration of the HPG axis in KS infants.

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

PURPOSE

Low testosterone (T) in Klinefelter's syndrome (KS) can contribute to typical features of the syndrome such as reduced bone mineral density, obesity, metabolic disturbances and increased cardiovascular risk. The aim of the present study is to review and meta-analyze all available information regarding possible differences in metabolic and bone homeostasis profile between T treated (TRT) or untreated KS and age-matched controls.

METHODS

We conducted a random effect meta-analysis considering all the available data from observational or randomized controlled studies comparing TRT-treated and untreated KS and age-matched controls. Data were derived from an extensive MEDLINE, Embase, and Cochrane search.

RESULTS

Out of 799 retrieved articles, 21 observational and 22 interventional studies were included in the study. Retrieved trials included 1144 KS subjects and 1284 healthy controls. Not-treated KS patients showed worse metabolic profiles (including higher fasting glycemia and HOMA index as well as reduced HDL-cholesterol and higher LDL-cholesterol) and body composition (higher body mass index and waist circumference) and reduced bone mineral density (BMD) when compared to age-matched controls. TRT in hypogonadal KS subjects was able to improve body composition and BMD at spinal levels but it was ineffective in ameliorating lipid and glycemic profile. Accordingly, TRT-treated KS subjects still present worse metabolic parameters when compared to age-matched controls.

CONCLUSION

TRT outcomes observed in KS regarding BMD, body composition and glyco-metabolic control, are similar to those observed in male with hypogonadism not related to KS. Moreover, body composition and BMD are better in treated than untreated hypogonadal KS. Larger and longer randomized placebo-controlled trials are advisable to better confirm the present data, mainly derived from observational studies.

Androgenetic alopecia: effects of oral finasteride on hormone profile, reproduction and sexual function

PURPOSE

Androgenetic Alopecia (AGA) is a common non-cicatricial alopecia. AGA treatment with finasteride was reported to have sexological side effects and its induced hormonal alterations could damage spermatogenesis. Thus, in patients affected by AGA undergoing oral therapy with Finasteride 1 mg/die, we aimed to evaluate the presence of modification in sperm parameters, hormone profile and sexual function.

METHODS

We retrospectively evaluated 55 male subjects aged 18-45 years with AGA who underwent systemic therapy with Finasteride 1 mg/die. Each subject underwent semen and blood hormone analysis, IIEF15 questionnaire administration at baseline (T0) at 6 (T6) and 12 (T12) months after the beginning of therapy and 1 year after treatment discontinuation (TD).

RESULTS

At T6 we detected a statistically significant worsening of total sperm number (232.4 ± 160.3 vs. 133.2 ± 82.0; p = 0.01 vs. T0) and abnormal forms (79.8 ± 6.0 vs. 82.7 ± 5.7; p < 0.05 vs. T0). No difference was found for all sperm parameters at T12 and T24, except for the percentage of abnormal forms (79.8 ± 6.0 vs. 82.6 ± 4.8; p < 0.05 T24 vs. T0). Testosterone levels were increased at T0 vs. T6 (22.1 ± 7.1 vs. 28.0 ± 8.0 ng/mL; p < 0.05). No significant differences of IIEF15 questionnaire were detected across the study.

CONCLUSIONS

Finasteride is associated with significant seminological and testosterone alterations, but no sexual dysfunctions were reported during treatment of these andrologically healthy subjects. Although, sperm parameters seem to return comparable to baseline after treatment discontinuation, it is advisable to perform a careful andrological evaluation before treatment.

Metabolic and cardiovascular risk factors in Klinefelter syndrome

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

Hormonal and metabolic gender differences in a cohort of myotonic dystrophy type 1 subjects: a retrospective, case-control study

PURPOSE

Myotonic dystrophy type 1 (DM1) is a genetic disorder caused by CTG expansion in the DMPK gene. The aim was to investigate the endocrine and metabolic aspects of DM1.

PATIENTS AND METHODS

Retrospective, case-control study. We compared pituitary, thyroid, adrenal, gonadal and liver function and glycolipid metabolism of 63 DM1 patients against 100 control subjects. Given age-related differences, 2 further subgroups were created to investigate the pituitary-gonadal axis: < 41 (1a) and ≥ 41 (1b) years old for male subjects and < 46 (2a) and ≥ 46 (2b) years old for female subjects. Testicular and thyroid ultrasounds were also performed in the DM1 group.

RESULTS

FT3 and FT4 were significantly lower in DM1 men than controls, while for both males and females, thyroglobulin, ACTH and cortisol were significantly higher in the DM1 group. Gonadotropin levels were significantly higher and inhibin B and DHEA-S levels significantly lower in DM1 patients than controls for both male subgroups. Testosterone and SHBG were significantly higher in controls than in patients for subgroup 1a. Prolactin was significantly higher in patients in subgroups 1b, while testosterone was lower in subgroup 2a than in age-matched female controls. A correlation between the number of CTG repeats and the percentage of male hypogonadal subjects was found. Finally, there was a worse glucose and lipid pattern and significantly higher transaminase and gamma-GT levels in both male and female patients.

CONCLUSIONS

The high frequency of endocrine and metabolic abnormalities in DM1 highlights the importance of endocrine monitoring to enable the prompt initiation of a suitable therapy.

CHK1-CENP B/MAD2 is associated with mild oxidative damage-induced sex chromosome aneuploidy of male mouse embryos during in vitro fertilization

A high incidence of aneuploidy is observed in vitro fertilization (IVF)-derived embryos, but the formation and repair mechanisms are unknown. Here, we investigated the effects of slightly increased reactive oxygen species (ROS) produced by in vitro culture conditions on embryo aneuploidy and the roles of the spindle assembly checkpoint (SAC) protein, mitotic arrest-deficient 2 (MAD2), and the DNA damage response (DDR) protein, checkpoint kinase 1 (CHK1), in aneuploidy repair. By assessing chromosome abnormalities via DAPI staining, karyotype analysis and next-generation sequencing technology, we demonstrated that mild oxidative damage mainly increased the risk of sex chromosome aneuploidy in male mouse embryos (41,XXY,+X and 41,XYY,+Y) through chromosome mis-segregation during the first mitosis. Isobaric tags for relative and absolute quantitation technology revealed that mild oxidative damage inhibited the expression of male reproduction-related proteins, including a kinase anchor protein 4 (AKAP4), whose gene is located on mouse/human Chromosome X. Under mild oxidative damage, abrogation of MAD2 by MAD2 inhibitor-1 (M2I-1) or CHK1 by siRNA microinjection increased sex chromosome mosaicism rate and reduced mitosis-promoting factor (MPF) activity. CHK1 inhibition also reduced kinetochore localization of centromere protein B (CENP B) and MAD2. These findings show that DDR and SAC are responsible for repair of sex chromosome mosaicism via the pCHK1 (S345)-CENP B/MAD2-MPF pathway; further, IVF may have negative effects on male offspring's reproduction ability, which ultimately depends on their continued repair capability. Therefore, we suggest that antioxidants, especially those targeting improved CHK1-MAD2 function, may be a promising therapeutic strategy to reduce aneuploidy formation of IVF-derived embryos and to maintain genome integrity of embryo and offspring.