Cause Of Non-obstructive Azoospermia Research Articles

Evaluation of the Results of Intracytoplasmic Sperm Injection and Microdissection Testicular Sperm Extraction Treatments in Patients with Nonobstructive Azoospermia According to Etiological Factors: A Retrospective Analysis

Objective: This study aimed to retrospectively compare the results of microdissection testicular sperm extraction (microTESE) and Intracytoplasmic sperm injection (ICSI) treatments in nonobstructive azoospermia (NOA) patients with different aetiologies. Determinants (clinical characteristics) for microTESE outcomes were compared between patients with successful sperm retrieval (SSR) and sperm retrieval failure (SRF). Methods: A total of 510 NOA patients who underwent microTESE between January 2015 and January 2024 were included in this study. Patients were classified according to the cause of NOA and SSR, fertilisation rate, clinical pregnancy, and overall live birth rate were evaluated. Results: The SSR rate was 44.1% in the whole population. The idiopathic patient group had the lowest SSR rate (X2: 34.81; p<0.01). There was no difference between the groups in terms of fertilisation rate, clinical pregnancy and overall live birth rate. There was a negative correlation between age and SSR rates in patients with idiopathic NOA (t:-0.27; p<0.01). SSR rates were higher in patients with cryptorchidism (right: t:0.8; P:0.003; left: t:0.72; p:0.002) and mumps orchitis (right: t:0.76; P<0.01; left: t:0.76; p=0.003). Conclusion: Etiology has a significant role in terms of SSR in patients with NOA. SSR was found to be significantly less in patients with idiopathic NOA compared to other causes. In addition, age and testicular volume were significant predictive factors for SSR in patients with idiopathic and acquired NOA.

O-134 Down regulation of Clock gene in testicle may affect energy metabolism of sertoli cell

Abstract Study question Whether decrease expression of Clock gene in the testis could affect the energy metabolism of Sertoli cells and what is the possible mechanism? Summary answer Down-regulating of Clock gene could regulate the expression of PIK3CB affect AMPK signaling pathways, significantly weakening the energy supply of sertoli cells in mouse testicular. What is known already The causes of Nonobstructive azoospermia (NOA) and other male infertility diseases are diverse and complex, including spermatogenesis and germ cell maturation at different stages of meiosis, the expression level of Clock gene maybe is one reason of which. In the testis of NOA patients, expression level of Clock gene was significantly decreased compared with Obstructive azoospermia (OA), meanwhile, the decrease of Clock gene expression can result in the decrease of male mouse fetal number. The decrease of Clock gene expression cause some kind of male infertility problem is confirmed, but the process and mechanism is not clear. Study design, size, duration Differential expression genes related to low expression of Clock and pathways related to spermatogenesis were screened out through transcriptome analysis on testicular tissue samples from patients with NOA(n = 24) and OA(n = 17). The model was established by transfecting mouse testicular Sertoli cell line (TM4 cells) with lentivirus containing Clock knock-down gene and energy metabolism effects were detected by Seahorse tests. Adifluorescein reporter gene was constructed to detect the binding of CLOCK and candidated differential expressed gene. Participants/materials, setting, methods Normal testis sequencing data were obtained from GTEX database as control. Combined with sequencing data, the differentially expressed genes were obtained as candidate gene, which expression was verified by RT-qPCR, Western-blotting. Energy metabolism were detected by Seahorse mitochondrial-stress test, glycolysis-rate test. Adifluorescein reporter gene for the promoter regions of candidate gene was constructed and transfected into TM4 cells to detect whether CLOCK could regulate candidate gene by binding to the E-box of the promoter region. Main results and the role of chance After GO(GeneOntology) and KEGG(Kyoto Encyclopedia of Genes and Genomes) enrichment analysis, PIK3CB which involved in AMPK signaling pathway was selected for further verification and molecular mechanism study. In Seahorse tests, the basal respiratory capacity, maximal respiratory capacity OCR, spare respiratory capacity and ATP-related respiratory capacity of TM4 cells were significantly decreased after Clock gene knockdown, but there were no significant differences in glycolytic rate, basal glycolysis, compensatory glycolysis level and glycolytic rate. RT-qPCR and Western-blotting confirmed that after knock down of Clock gene, the expression level of Pik3cb gene was down-regulated. That imply when Clock gene is decreased, it regulates the expression of PIK3CB affects AMPK signaling pathways, weakening the ability of mouse testicular sertoli cells to supply energy to various levels of spermatogenic cells and sperm cells, which may be one reason for the occurrence of nonobstructive azoospermia. During this process, there were significant changes in the mitochondrial energy supply of testicular supporting cells, but no significant changes in glycolysis. Finally, the dual luciferin report showed that the Clock gene could bind to the promoter regions of Pik3cb to regulate the expression of PIK3CB, and that the promoter of PIK3CB was activated by the transcription factor CLOCK. Limitations, reasons for caution Although we identified that Clock gene could bind to the promoter regions of Pik3cb to regulate the expression of PIK3CB and affect AMPK signaling pathways, weakening the ability of mouse testicular sertoli cells to supply energy, the available expression level and whether it will be work in vivo is unknown. Wider implications of the findings The results imply that the main energy changes affect the occurrence and development of spermatogonia and primary spermatocytes near the base of the seminiferous tubules are related to the influence of Clock on genes involved in regulating mitochondrial energy supply. It need more further studies. Trial registration number not applicable

Testicular Sperm Extraction in Non-Obstructive Azoospermic Patients with Sertoli Cell-Only Syndrome Testicular Histology

INTRODUCTION: Sertoli cell-only syndrome (SCOS) is a prevalent cause of non-obstructive azoospermia (NOA) in males, where seminiferous tubules exclusively contain Sertoli cells, leading to minimal or absent spermatogenesis. Success rates for sperm retrieval in these cases vary significantly. We aimed to investigate the sperm retrieval rate with microdissection TESE (mTESE) in NOA patients with SCOS testicular histology and the factors that may affect it. MATERIAL AND METHODS: Patients who underwent mTESE due to NOA were retrospectively evaluated. Only patients with a histopathological diagnosis of SCOS were included in the study. Those with other histopathological diagnoses, those who underwent conventional TESE (cTESE) were excluded from the study. The sperm retrieval rate after mTESE was calculated for patients with a pathology result of SCOS. The age, testicular volume, and Follicle-Stimulating Hormone (FSH) level of the groups with and without sperm were compared. RESULTS: In our study, 186 patients with testicular histopathology diagnosed as SCOS were included. The rate of sperm retrieval after TESE in these patients was 28%. In patients with retrieved sperm, the mean age was 33.8 ± 5.4 years, the mean testicular volume was 11.1 ± 6.3 ml, and the mean FSH level was 22.5 ± 12.7 mIU/ml. In patients without retrieved sperm, the mean age was 33.8 ± 6.1 years, the mean testicular volume was 10.3 ± 6.1 ml, and the mean FSH level was 21.0 ± 9.8 mIU/ml. There was no significant difference observed in mean age, testicular volume, and FSH level between the group with retrieved sperm and the group without retrieved sperm (p=0.97, p=0.24, p=0.38, respectively). CONCLUSION: The findings of our study can be used for counseling men with NOA. Obtaining intratesticular sperm is possible in the presence of NOA and a diagnosis of SCOS histology. Therefore, patients undergoing testicular biopsy with TESE for histological examination can simultaneously prepare for intracytoplasmic sperm injection if sperm is found.

Artificial intelligence: to a better predictive strategy for testicular sperm extraction outcome in azoospermia

Azoospermia, defined as the absence of sperm in the semen, is found in 10-15% of infertile patients. Two-thirds of these cases are caused by impaired spermatogenesis, known as non-obstructive azoospermia (NOA). In this context, surgical sperm extraction using testicular sperm extraction (TESE) is the best option and can be offered to patients as part of fertility preservation, or to benefit from in vitro fertilization. The aim of the preoperative assessment is to identify the cause of NOA and evaluate the status of spermatogenesis. Its capacity to predict TESE success remains limited. As a result, no objective and reliable criteria are currently available to guide professionals on the chances of success and enable them to correctly assess the benefit-risk balance of this procedure. Artificial intelligence (AI), a field of research that has been rapidly expanding in recent years, has the potential to revolutionize medicine by making it more predictive and personalized. The aim of this review is to introduce AI and its key concepts, and then to examine the current state of research into predicting the success of TESE.

(278) The Loss of Histone Reader Phf7 Leads to Immune Pathways Activation via Endogenous Retroviruses During Spermiogenesis

Abstract Introduction PHF7 has been identified as playing a crucial role in germline development in animals. However, its correlation with human infertility remains ambiguous. Objective To ascertain if a germline mutation in the human PHF7 gene correlates with azoospermic patients and to further determine if this mutation is a potential cause of non-obstructive azoospermia. Methods Genetic screening of azoospermic patients for PHF7 mutations. Using Phf7 knockout mice models to simulate the human mutation, aiming to validate if these mutations are directly responsible for male infertility. Investigating the role of endogenous retroviruses related to Phf7 deletion and its link to activating the immune pathway. Results A germline mutation of the human PHF7 gene was identified in azoospermic patients. In the Phf7 knockout mice model, male infertility was observed, specifically stemming from an inhibited histone-to-protamine exchange process. The absence of spermatogenesis due to the Phf7 deletion was found to be associated with the activation of the immune pathway, mediated by endogenous retroviruses. PPARα was identified as a significant factor in the testis, which is suppressed by endogenous retroviruses. Conclusions PHF7 is an essential gene associated with human infertility, particularly in non-obstructive azoospermic patients. Its role as an epigenetic reader became evident, and the absence of PHF7 leads to immune pathway activation. The study also highlighted that the PPARα agonist, Astaxanthin, holds promise as a therapeutic agent to treat male infertility resulting from PHF7 mutations. Disclosure No.

Advocating hormonal treatment to prevent adult in-fertility in patients diagnosed with congenital un-descended testes.

In 2007 the Nordic group came to the following unanimous conclusions: In general, hormonal treatment is not recommended, considering the poor immediate results and the possible long-term adverse effects on spermatogenesis. Thus, surgery is to be preferred. However, defective mini puberty inducing insufficient gonadotropin secretion is one of the most common causes of nonobstructive azoospermia in men suffering from congenital isolated unilateral or bilateral cryptorchidism. The extent of alteration in the unilateral undescended testis correlate with the contralateral descended testis, indicating that unilateral cryptorchidism is a bilateral disease. Idiopathic central hypogonadism explains the phenomenon of defective mini puberty in otherwise healthy cryptorchid boys. We therefore recommend hormonal treatment for cryptorchid boys with defective mini puberty. Gonadotropin releasing hormone agonist (GnRHa) treatment following surgery to correct cryptorchidism restores mini puberty via endocrinological and transcriptional effects and prevents adult infertility in most cases. Several genes are important for central hypogonadotropic hypogonadism in mammals, including many that are transcribed in both the brain and testis. At the molecular level, there is no convincing evidence that heat shock is responsible for the observed pathological testicular changes. Thus, impaired transformation of gonocytes is not the result of temperature stress but rather a hormonal imbalance. Cryptorchidism should therefore be considered a serious andrological problem that cannot be successfully treated by early orchidopexy alone.

Microdissection Testicular Sperm Extraction.

Nonobstructive azoospermia (NOA) is among the most common causes of male infertility. For men with NOA seeking fertility treatment, microdissection testicular sperm extraction (microTESE) is the best option for retrieving sperm, which can be used with in vitro fertilization-intracytoplasmic sperm injection to achieve pregnancy in their partner. With the aid of the operating microscope, microTESE allows for thorough evaluation of the testis tissue and selection of seminiferous tubules that appear most capable of sperm production. Rates of success with microTESE vary depending on the underlying cause of NOA and the center at which the procedure is performed. Not all patients are candidates for microTESE, and those who are candidates should be counseled on the likelihood of sperm retrieval and the potential for changes in postoperative testis function.

Novel MEIOB pathogenic variants including a homozygous non-canonical splicing variant, cause meiotic arrest and human non-obstructive azoospermia.

Non-obstructive azoospermia (NOA) is the most severe form of human male infertility, and the genetic causes of NOA with meiotic arrest remain largely unclear. In this study, we identified novel compound heterozygous MEIOB variants (c.814C > T: p.R272X and c.976G > A: p.A326T) and a previously undescribed homozygous non-canonical splicing variant of MEIOB (c.528 + 3A > C) in two NOA-affected individuals from two irrelevant Chinese families. MEIOB missense variant (p.A326T) significantly reduced protein abundance and nonsense variant (p.R272X) produced a truncated protein. Both of two variants impaired the MEIOB-SPATA22 interaction. The MEIOB non-canonical splicing variant resulted in whole Exon 6 skipping by minigene assay, which was predicted to produce a frameshift truncated protein (p.S111Rfs*32). Histological and immunostaining analysis indicated that both patients exhibited a similar phenotype as we previously reported in Meiob mutant mice, that is, absence of spermatids in seminiferous tubules and meiotic arrest. Our study identified three novel pathogenic variants of MEIOB in NOA patients, extending the mutation spectrum of the MEIOB and highlighting the contribution of meiotic recombination related genes in human fertility.

A novel splicing mutation in helicase for meiosis 1 leads to non-obstructive azoospermia.

Non-obstructive azoospermia (NOA) is an essential cause of male infertility for which treatment options are limited. The pathogenic mechanism of NOA, especially idiopathic NOA, remains unclear. Gene variations are associated with the occurrence of NOA. Our study was performed to investigate the genetic causes of NOA. Whole exome sequencing (WES) was performed in two probands diagnosed with NOA from a Chinese family. Sanger sequencing was applied to verify the pathogenic variants. A minigene assay was carried out to identify the effect of the splicing variants. We detected a novel homozygous variant (c.2681-3T > A) in the HFM1 gene in the two siblings diagnosed with NOA, and their parents carried heterozygous mutations in the same gene. The results of the minigene assay revealed this splicing variant results in exon25 of HFM1 being skipped, leading to a protein truncation (p.Trp894Cysfs*44). Our results showed that a deleterious splicing variant in HFM1 was related to NOA in these two patients. This novel variant of HFM1 may serve as a potential genetic biomarker for NOA patients.

Microdissection testicular sperm extraction outcomes in azoospermic patients with bilateral orchidopexy.

Cryptorchidism is considered to be one of the most common causes of non-obstructive azoospermia. There are several surgical techniques to retrieve sperm in these patients. Microdissection testicular sperm extraction (m-TESE) is a recent sperm retrieval technique which is considered to be a safe, non-blind, and feasible method. This study aimed to investigate sperm retrieval rate (SRR) by the mTESE method in patients who have undergone orchidopexy due to bilateral cryptorchidism. In this retrospective study, 56 ex-cryptorchid patients, who underwent mTESE due to post orchidopexy azoospermia, were included. Patients with hypogonadotropic hypogonadism, Klinefelter syndrome, azoospermia factors (AZF) microdeletion, or chromosomal translocation were excluded from the study. Data were obtained from medical files. SRR in this study was 46%. Patients were divided into two groups of negative (n=30) and positive (n=26) based on the sperm extraction outcomes. There was no statistically significant difference between two groups regarding the mean age at mTESE, mean age at orchidopexy, testicular size, and serum testosterone concentration. However, testicular location, histological patterns, FSH, and LH level showed to have statistically significant relation with sperm retrieval results. But, according to our logistic regression, none of the included variable in the model including FSH, LH, histopathology, and testis location have a significant effect on the presence of the sperm. In the present study, SRR was significantly higher in patients with scrotal testis and low level of FSH and LH. Performing mTESE could be recommended in ex-cryptorchid patients with post orchidopexy NOA. Preoperative testicular biopsy seems to be unnecessary while clinical criteria can perfectly define NOA.

New Insights into the Role of INSL-3 in the Development of Cryptorchidism

Cryptorchidism, defined as the failure of at least one or both testicles to descend into the scrotal pouches, is the most frequent (1.6–9% at birth, 1/20 males at birth) congenital anomaly encountered in newborn males, resulting in one of the most frequent causes of non-obstructive azoospermia in men. Similar to other congenital malformations, cryptorchidism is thought to be caused by endocrine and genetic factors, combined with maternal and environmental influences. The etiology of cryptorchidism is unknown, as it involves complex mechanisms aiming to control the testicular development and descent from their initial intra-abdominal location in scrotal pouches. The implication of insulin-like 3 (INSL-3) associated with its receptor (LGR8) is critical. Genetic analysis discloses functionally deleterious mutations in INSL3 and GREAT/LGR8 genes. In this literature review, we discuss and analyze the implication of INSL3 and the INSL3/LGR8 mutation in the occurrence of cryptorchidism in both human and animal models.

MP30-07 EVALUATION OF MTESE OUTCOMES IN PATIENTS WITH PARTIAL AZFb Y CHROMOSOME MICRODELETIONS

You have accessJournal of UrologyCME1 Apr 2023MP30-07 EVALUATION OF MTESE OUTCOMES IN PATIENTS WITH PARTIAL AZFb Y CHROMOSOME MICRODELETIONS Jonathan Gal, Jessica Marinaro, Anna Mielnik, and Peter Schlegel Jonathan GalJonathan Gal More articles by this author , Jessica MarinaroJessica Marinaro More articles by this author , Anna MielnikAnna Mielnik More articles by this author , and Peter SchlegelPeter Schlegel More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003258.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Y chromosome microdeletions (YCMD) are a common cause of non-obstructive azoospermia. While men with deletions in the azoospermia factor C (AZFc) region have a high likelihood of having sperm in the ejaculate, or sperm retrievable with effective microdissection testicular sperm extraction (mTESE) procedure, those with complete deletions in the AZFa or AZFb regions have a poor prognosis for identification of sperm. Men with AZFa deletions typically do not have any germ cells, and no men, to-date, with complete AZFb deletions have had usable sperm identified. Partial deletions of AZFb appear to portend a different prognosis for fertility potential. Our objective was to evaluate semen parameters, sperm retrieval rates and fertility outcomes in men with partial deletions of the AZFb region. METHODS: We retrospectively reviewed 468 men with YCMDs who underwent testing at our institution from 4/1996 to 8/2022. Of these, we identified 20 men with partial AZFb deletions, defined as a deletion of some but not all tested segments from sY1227 to sY1291. Of these, 8 had documented semen analysis and underwent mTESE by a single, high-volume surgeon (PS). Sperm retrieval rate (SRR) was defined as the presence of mature sperm identified after processing by a trained andrologist. RESULTS: Of the 8 men with a partial AZFb deletion, 7 (87.5%) had a sY117-sY1291 deletion, and one (12.5%) had an sY1227-sY1192 deletion. All 8 men (100%) were azoospermic. Mean testosterone levels were 450.5 ± 350.5 (ng/dL), Mean FSH 6.5±2.8 (mIU/mL). After mTESE, 1 of 7 men (14%) with an sY117-sY1291 deletion was found to have sperm, and the 1 man with a sY1227-sY1192 deletion was found to have round spermatids on histology. Overall, the SRR was 12%. All pathology specimens (n=8, 100%) demonstrated maturation arrest. CONCLUSIONS: In this large series, we demonstrate that while patients with partial AZFb deletions are azoospermic, it is possible to find sperm at least for some men with mTESE. Distinguishing partial from complete AZFb deletions may have prognostic value. Further work is needed to determine which men with partial AZFb deletions are more likely to have a successful mTESE procedure. Source of Funding: Author JG is supported in part by the Frederick J. and Theresa Dow Wallace Fund of the New York Community Trust © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e393 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jonathan Gal More articles by this author Jessica Marinaro More articles by this author Anna Mielnik More articles by this author Peter Schlegel More articles by this author Expand All Advertisement PDF downloadLoading ...

Bi-allelic MEI1 variants cause meiosis arrest and non-obstructive azoospermia.

Non-obstructive azoospermia (NOA) is characterized by the failure of sperm production due to testicular disorders and represents the most severe form of male infertility. Growing evidences have indicated that gene defects could be the potential cause of NOA via genome-wide sequencing approaches. Here, bi-allelic deleterious variants in meiosis inhibitor protein 1 (MEI1) were identified by whole-exome sequencing in four Chinese patients with NOA. Testicular pathologic analysis and immunohistochemical staining revealed that spermatogenesis is arrested at spermatocyte stage, with defective programmed DNA double-strand breaks (DSBs) homoeostasis and meiotic chromosome synapsis in patients carrying the variants. In addition, our results showed that one missense variant (c.G186C) reduced the expression of MEI1 and one frameshift variant (c.251delT) led to truncated proteins of MEI1 in in vitro. Furthermore, the missense variant (c.T1585A) was assumed to affect the interaction between MEI1 and its partners via bioinformatic analysis. Collectively, our findings provide direct genetic and functional evidences that bi-allelic variants in MEI1 could cause defective DSBs homoeostasis and meiotic chromosome synapsis, which subsequently lead to meiosis arrest and male infertility. Thus, our study deepens our knowledge of the role of MEI1 in male fertility and provides a novel insight to understand the genetic aetiology of NOA.

Identification of risk genes in Chinese nonobstructive azoospermia patients based on whole-exome sequencing.

Nonobstructive azoospermia (NOA) is a severe condition in infertile men, and increasing numbers of causative genes have been identified during the last few decades. Although certain causative genes can explain the presence of NOA in some patients, a proportion of NOA patients remain to be addressed. This study aimed to investigate potential high-risk genes associated with spermatogenesis in idiopathic NOA patients by whole-exome sequencing. Whole-exome sequencing was performed in 46 male patients diagnosed with NOA. First, screening was performed for 119 genes known to be related to male infertility. Next, further screening was performed to determine potential high-risk causative genes for NOA by comparisons with 68 healthy male controls. Finally, risk genes with high/specific expression in the testes were selected and their expression fluctuations during spermatogenesis were graphed. The frequency of cystic fibrosis transmembrane conductance regulator (CFTR) gene pathogenic variant carriers was higher in the NOA patients compared with the healthy controls. Potential risk genes that may be causes of NOA were identified, including seven genes that were highly/specifically expressed in the testes. Four risk genes previously reported to be involved in spermatogenesis (MutS homolog 5 [MSH5], cilia- and flagella-associated protein 54 [CFAP54], MAP7 domain containing 3 [MAP7D3], and coiled-coil domain containing 33 [CCDC33]) and three novel risk genes (coiled-coil domain containing 168 [CCDC168], chromosome 16 open reading frame 96 [C16orf96], and serine protease 48 [PRSS48]) were identified to be highly or specifically expressed in the testes and significantly different in the 46 NOA patients compared with 68 healthy controls. This study on clinical NOA patients provides further evidence for the four previously reported risk genes. The present findings pave the way for further functional investigations and provide candidate risk genes for genetic diagnosis of NOA.

Clinical and laboratory differences between chromosomal and undefined causes of non-obstructive azoospermia: A retrospective study.

Knowledge of clinical and laboratory differences between chromosomal and undefined causes aids etiological research on non-obstructive azoospermia. Compare clinical and laboratory differences between men with non-obstructive azoospermia due to chromosomal anomalies versus undefined causes. A cross-sectional retrospective study conducted at a public university hospital in Campinas (Brazil). All men aged 20-40 years with non-obstructive azoospermia were included in the analysis. The 107 cases included 14 with Klinefelter syndrome (KS) (13%), 1 with mosaic KS, 4 with sex development disorders (2 testicular XX, 1 NR5A1 gene mutation, and 1 mild androgen insensitivity syndrome) (4%), 9 with other non-obstructive azoospermia etiologies (8%), and 79 with undefined causes. The 22 chromosomal anomaly cases (14 KS, 1 mosaic KS, 2 testicular XX, 4 sex chromosome anomalies, and 1 autosomal anomaly) were compared with the 79 undefined cause cases. The KS group had lower average testicular volume, shorter penile length, and lower total testosterone levels but greater height, arm span, serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, and gynecomastia frequency (absent in the undefined group and affecting more than half of the KS group). Patients with testicular XX DSD had LH, FSH, and penile length data intermediate between the KS and undefined cause groups, testicular volume similar to the KS group, and other data similar to the undefined group. Clinical and laboratory data differentiate men with non-obstructive azoospermia and chromosomal anomalies, particularly KS and testicular XX, from those with undefined causes or other chromosomal anomalies.

SEMEN ANALYSIS FINDINGS FROM LARGE COHORT OF ADOLESCENTS WITH KLINEFELTER SYNDROME

INTRODUCTION: Klinefelter Syndrome (KS) is the most common genetic condition cause of non-obstructive azoospermia (NOA). KS also often results in decreased testicular growth and testosterone production. Because of this, exogenous testosterone therapy is commonly prescribed for KS patients to treat hypogonadism, but this may have additional impacts to future fertility potential. Current clinical practice is to have KS adolescent patients provide frequent semen samples in an effort to identify potential sperm for early cryopreservation.

Identification of a new splice-acceptor mutation in HFM1 and functional analysis through molecular docking in nonobstructive azoospermia.

To investigate the genetic cause of nonobstructive azoospermia (NOA). We performed whole exome sequencing (WES) on the proband who had three relatives suffering from NOA. We used a list of candidate genes which have high expression level in testis and their mutations have been reported in NOA. Sanger sequencing verified the identified variant and its structural and functional consequence was evaluated by protein three-dimensional (3D) structure prediction and protein-ligand docking. WES revealed a novel splice-acceptor mutation (c.1832-2A>T) in helicase for meiosis 1 (HFM1) gene, which co-segregated with the NOA in this family. 3D structural models were generated and verified. Molecular docking indicated that the c.1832-2A>T mutation affects not only the ADP binding residues but also the hydrogen bond interactions. The ADP binding site will be lost in the mutant protein, potentially causing defective crossover and synapsis. We report that the c.1832-2A>T mutation is the likely cause of NOA in the family studied. Regarding that many reported NOA genes are involved in the formation of crossovers and synapsis and have critical roles in the production of germ cells, we suggest that such genes should be considered for screening of infertility among large cohorts of infertile individuals.

Utility of evaluating semen samples from adolescents with Klinefelter Syndrome for cryopreservation: A multi-institution evaluation

Klinefelter Syndrome (KS) is the most common genetic condition cause of non-obstructive azoospermia (NOA). KS also often results in decreased testicular growth and testosterone production. Because of this, exogenous testosterone therapy is commonly prescribed for KS patients to treat hypogonadism, but this may have additional impacts to future fertility potential. KS adolescent patients may be asked to provide multiple semen samples to identify potential sperm for early cryopreservation. To develop a multi-institutional database to evaluate the prevalence of sperm in the ejaculate of adolescent KS patients. A retrospective study was performed of all adolescent KS patients seen at two high-volume tertiary male infertility clinics between 2015 and 2020. Adolescence was defined as individuals aged 12-19 years, as per the World Health Organization. Demographic information data including weight, height, medical comorbidities, and concurrent medications were collected. Serum hormone levelsincluding FSH, LH, and testosterone were collected, as well as any available semen analysis data. A total of 116 patients were identified and included in the database. A total of 100 (86.2%) had hormone data available and 48 (41.3%) had semen analysis data. Of the 48 patients with semen analyses, only 4 (8.3%) patients had rare sperm in the ejaculate while the remaining had azoospermia (91.7%). None of the specimens were suitable for cryopreservation. The average serum total testosterone level of adolescent KS patients was 181±216ng/dL. FSH levels were 14.3±18.8 IU/L (normal 0.3-10.0 IU/L) and LH levels were 7.8±12.4 IU/L (normal 1.2-7.8 IU/L). A total of 17 patients repeated a semen analysis, and in no instance did this result in sperm where there was none previously. The findings from a large multicenter retrospective cohort of adolescent KS patients suggest that a single semen analysis is sufficient for attempted cryopreservation purposes, and that multiple semen analyses is not needed.

Whole Exome Sequencing Identifies Genes Associated With Non-Obstructive Azoospermia.

Background: Non-obstructive azoospermia (NOA) affects nearly 1% of men; however, the landscape of the causative genes is largely unknown. Objective: To explore the genetic etiology which is the fundamental cause of NOA, a prospective case-control study and parental–proband trio linkage analysis were performed. Materials: A total of 133 patients with clinicopathological NOA and 343 fertile controls were recruited from a single large academic fertility center located in Northeast China; in addition, eleven trio families were available and enrolled. Results: Whole exome sequencing-based rare variant association study between the cases and controls was performed using the gene burden association testing. Linkage analysis on the trio families was also interrogated. In total, 648 genes were identified to be associated with NOA (three of which were previously reported), out of which six novel genes were found further associated based on the linkage analysis in the trio families, and involved in the meiosis-related network. Discussion and Conclusion: The six currently identified genes potentially account for a fraction (3.76%, 5 out of 133 patients) of the heritability of unidentified NOA, and combining the six novel genes and the three previously reported genes together would potentially account for an overall 6.77% (9 out of 133 patients) heritability of unidentified NOA in this study.

Novel exon mutation in SYCE1 gene is associated with non-obstructive azoospermia.

Non‐obstructive azoospermia (NOA) is a common cause of male infertility, and genetic problems, such as chromosomal abnormalities and gene mutations, are important causes of NOA. Our centre received a case of NOA, in which no mature sperm was found during microdissection testicular sperm extraction. A postoperative pathological examination revealed that testicular spermatogenesis was blocked. Target region capture combined with high‐throughput sequencing was used to screen for male infertility‐related gene mutations. Sanger sequencing further confirmed that the SYCE1 gene, a central component of the synaptonemal complex (SC) during meiosis, had a homozygous deletion mutation in the tenth exon (c.689_690del; p.F230fs). Through molecular biological studies, we discovered altered expression and nuclear localization of the endogenous mutant SYCE1. To verify the effects in vitro, wild‐ and mutated‐type SYCE1 vectors were constructed and transfected into a human cell line. The results showed that the expression and molecular weight were decreased for SYCE1 containing c.689_690del. In addition, mutated SYCE1 was abnormally located in the cytoplasm rather than in the nucleus. In summary, our research suggests that the novel homozygous mutation (c.689_690del; p.F230fs) altered the SYCE1 expression pattern and may have disturbed SC assembly, leading to male infertility and to a barrier to gamete formation. We reported for the first time that a frameshift mutation occurred in the exon region of SYCE1 in an NOA patient. This study is beneficial for accurate NOA diagnosis and the development of corresponding gene therapy strategies.