Genetics of the human Y chromosome and its association with male infertility

European Association of Urology Guidelines on Male Sexual and Reproductive Health: 2025 Update on Male Infertility

BACKGROUND AND OBJECTIVE

To present a summary of the updated 2025 European Association of Urology (EAU) Guidelines on Sexual and Reproductive Health (SRH) on male infertility, providing practical recommendations on the clinical work-up with a focus on diagnosis, treatment and follow-up.

METHODS

For the 2025 SRH guidelines, new and relevant evidence was identified, collated, and appraised via a structured assessment of the literature. Databases searched included Medline, EMBASE, and the Cochrane Libraries. Recommendations within the guidelines were developed by the panel to prioritise clinically important care decisions. The strength of each recommendation was determined according to a balance between desirable and undesirable consequences of alternative management strategies, the quality of the evidence (including the certainty of estimates), and the nature and variability of patient values and preferences.

KEY FINDINGS AND LIMITATIONS

Key recommendations emphasise the importance of a thorough urological assessment of all men seeking medical help for fertility problems to ensure appropriate treatment. The guidelines also stress the clinical relevance of a parallel investigation of the female partner during the diagnostic and management work-up of the infertile couple, to promote shared-decision making in terms of timing and therapeutic strategies. Furthermore, the guidelines recommend to counsel all infertile men and men with abnormal semen parameters on the associated health risks. Key changes in the male infertility guidelines for 2025 include: the addition of two new sections addressing exome sequencing and probiotic treatment; and significant update of the evidence base and recommendations for the diagnostic work-up of male infertility.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This overview of the 2025 SHR guidelines offers valuable insights into the diagnosis, classification, treatment and follow-up of male factor infertility and are designed for effective integration into clinical practice.

The effects of loss of Y chromosome on male health

Loss of Y chromosome (LOY) is the most commonly occurring post-zygotic (somatic) mutation in male individuals. The past decade of research suggests that LOY has important effects in shaping the activity of the immune system, and multiple studies have shown the effects of LOY on a range of diseases, including cancer, neurodegeneration, cardiovascular disease and acute infection. Epidemiological findings have been corroborated by functional analyses providing insights into the mechanisms by which LOY modulates the immune system; in particular, a causal role for LOY in cardiac fibrosis, bladder cancer and Alzheimer disease has been indicated. These insights show that LOY is a highly dynamic mutation (such that LOY clones expand and contract with time) and has pleiotropic, cell-type-specific effects. Here, we review the status of the field and highlight the potential of LOY as a biomarker and target of new therapeutics that aim to counteract its negative effects on the immune system.

Sperm retrieval, fertilization rates, and clinical outcomes of infertile men with Y chromosome microdeletion A retrospective cohort study

INTRODUCTION

We aimed to explore whether a Y chromosome microdeletion (YCM) confers adverse effects on surgical sperm retrieval potential and intracytoplasmic sperm injection (ICSI) outcomes in men with azoospermia and severe oligospermia.

METHODS

This was a retrospective cohort study that included infertile men with azoospermia or severe oligospermia who were evaluated for karyotype analysis and YCM testing at a university-affiliated hospital between 2010 and 2022. Outcomes of microdissection testicular sperm extraction (mTESE) for surgical sperm retrieval were compared between men diagnosed with YCM and the control group, in which no YCM was found. Additionally, patients from each group who underwent in vitro fertilization (IVF)-ICSI cycle using ejaculated sperm or surgically retrieved mature spermatozoa were compared regarding their IVF-ICSI cycle outcomes, fertilization rates, cleavage, and blastocyst formation, and clinical pregnancy rates.

RESULTS

A total of 116 azoospermic and oligospermic men who underwent YCM testing were included in the study: 19 with YCM and 97 without. Overall, nine mTESE procedures were performed for patients with YCM and 38 for men from the control group. There were no significant differences between the YCM and control groups in mature sperm retrieval rates (11.1% vs. 26.3%, p=0.663), although a trend towards higher rates of elongated and round spermatids as the most mature germ cell was noted in the YCM group (66.7% vs. 28.9%, p=0.054). Of the 13 men with mature sperm - either ejaculated or surgically retrieved (mTESE) - that had known ICSI cycle outcomes, three men had proven YCMs and 10 controls had no identified YCMs. Basic characteristics were similar between the groups, except for testosterone levels, which were higher in the YCM group (23.0±13.1 vs. 9.4±6.4 nmol/L, p=0.027). Fertilization rates and cleavage rates were similar between the YCM and control groups (42.3% vs. 49.7% and 42.3% vs. 39.3%, p=0.491 and 0.774, respectively). Blastocyst formation rates, and pregnancy rates, while not statistically significant, showed a trend for favorable outcomes in the control group compared to the YCM group (24.1% vs. 7.7%, 72.7% vs. 20.0%, p=0.078 and 0.106, respectively).

CONCLUSIONS

YCM does not affect sperm retrieval rates. Fertilization and cleavage rates are not impaired by microdeletions, while blastocyst formation rates and clinical pregnancy rates per embryo transfer follow a non-significant trend for unfavorable outcomes in the YCM group. Clinical and embryonic development results should be interpreted with caution, as these groups are relatively small.

Higher frequency of homologous chromosome pairing in human adult aortic endothelial cells

During mitosis, pairing of homologous chromosomes can be detrimental and has been correlated with gene misregulation, chromosomal aberrations, and various pathological diseases. We previously demonstrated that homologous chromosomes are spatially segregated, or antipaired, in neonatal human endothelial cells at metaphase/anaphase, which may help prevent abnormal recombination. However, it is unclear if this antipairing persists in adult endothelial cells. To test whether the antipairing, or one homolog per nuclear hemisphere motif, is conserved in adult endothelial cells, we examined human aortic endothelial cells at metaphase. Using ImmunoFISH and high-resolution confocal microscopy to visualize the chromosomes and centrosomes, we found that small homologous chromosomes 13, 15, 17, 19, 21, 22, and the sex chromosomes, XY, exhibit a loss of spatial segregation in human adult aortic endothelial cells. In contrast, fewer adult endothelial cells showed a loss of segregation for the larger chromosomes 1, 4, and XX, suggesting a gradual decline in the fidelity of spatial segregation of homologous chromosomes. Notably, we observed a higher frequency of abnormal pairing in both small and large chromosomes in adult aortic endothelial cells as compared to neonatal umbilical vein endothelial cells. These findings suggest that mechanisms governing chromosome antipairing may decline with aortic endothelial cell age, leading to increased susceptibility to abnormal pairing and cardiovascular disease.

Generation of a KDM5D knockout human embryonic stem cell line with CRISPR/Cas9 technology

KDM5D is a gene implicated in spermatogenic failure and sex-related differences in colon cancer progression, though its role in spermatogenesis remains unclear. We successfully generated a KDM5D knockout human embryonic stem cells using CRISPR/Cas9 technology. This knockout cell line provides a valuable model for studying KDM5D's function in spermatogenesis and its influence on sex differences in various diseases.

FertilitY Predictor-a machine learning-based web tool for the prediction of assisted reproduction outcomes in men with Y chromosome microdeletions

PURPOSE

Y chromosome microdeletions (YCMD) are a common cause of azoospermia and oligozoospermia in men. Herein, we developed a machine learning-based web tool to predict sperm retrieval rates and success rates of assisted reproduction (ART) in men with YCMD.

METHODS

Data on ART outcomes of men with YCMD who underwent ART were extracted from published studies by performing a systematic review. This data was used to develop a web-based predictive algorithm using machine learning.

RESULTS

FertilitY Predictor classifies the type of YCMD into AZFa, AZFb, AZFc, their combinations, and gr/gr deletions based on the genetic markers as input. Further, it predicts the probability of sperm retrieval, fertilization rate, clinical pregnancy rate, and live birth rate based on the type of YCMD. Validation studies demonstrated its high accuracy and predictability for sperm retrieval, clinical pregnancy rates, and live birth rates. The tool predicts that men with deletions have a chance of sperm retrieval that varies with type of deletions, the clinical pregnancy rates and live birth rates are lower in men with AZF deletions. A trial version of the tool is available at http://fertilitypredictor.sbdaresearch.in .

CONCLUSIONS

FertilitY Predictor allows users to classify AZFa, AZFb, AZFc, and gr/gr deletions and also predict the outcomes of ART based on the type of deletions.

TRIAL REGISTRATION

PROSPERO (CRD42022311738).

Complete analysis of G-quadruplex forming sequences in the gapless assembly of human chromosome Y

Recent advancements have finally delivered a complete human genome assembly, including the elusive Y chromosome. This accomplishment closes a significant knowledge gap. Prior efforts were hampered by challenges in sequencing repetitive DNA structures such as direct and inverted repeats. We used the G4Hunter algorithm to analyze the presence of G-quadruplex forming sequences (G4s) within the current human reference genome (GRCh38) and the new telomere-to-telomere (T2T) Y chromosome assemblies. This analysis served a dual purpose: identifying the location of potential G4s within the genomes and exploring their association with functionally annotated sequences. Compared to GRCh38, the T2T assembly exhibited a significantly higher prevalence of G-quadruplex forming sequences. Notably, these repeats were abundantly located around precursor RNA, exons, genes, and within protein binding sites. This remarkable co-occurrence of G4-forming sequences with these critical regulatory regions suggests their role in fundamental DNA regulation processes. Our findings indicate that the current human reference genome significantly underestimated the number of G4s, potentially overlooking their functional importance.

Investigation of Y chromosome microdeletions in algerian children with hypospadias

BACKGROUND

Hypospadias is a congenital condition where the urethral opening is located on the underside of the penis instead of at the tip. The Y chromosome, particularly the Azoospermia Factor (AZF) loci, plays a crucial role in male sexual development. Microdeletions in this region have been implicated in male infertility and hypothesized to contribute to congenital malformations like hypospadias. However, the relationship between Y chromosome microdeletions and hypospadias remains unclear, prompting further investigation. The study aimed to investigate the presence of Y chromosome microdeletions in Algerian patients with hypospadias and compare these findings to a control group, to assess whether these genetic anomalies contribute to the development of this condition.

METHODS

This study included 110 Algerian patients with hypospadias, aged between 1 month and 12 years, and a control group of 40 male children without hypospadias or other genitourinary anomalies. Both were recruited from pediatric surgery and endocrinology departments and included both isolated and non-isolated forms of hypospadias. Genomic DNA was extracted from peripheral leukocytes, and PCR analysis was performed to detect microdeletions in six AZF loci: sY84 and sY86 for AZFa, sY127 and sY134 for AZFb, and sY254 and sY255 for AZFc.

RESULTS

No Y chromosome microdeletions were detected in any of the 110 hypospadias patients or the 40 controls. Stratification by severity revealed significant associations between severe hypospadias and adverse perinatal outcomes, such as intrauterine growth restriction (IUGR), low birth weight, and preterm birth.

CONCLUSION

The absence of Y chromosome microdeletions in both hypospadias patients and controls suggests these anomalies are unlikely to play a primary role in the development of hypospadias in this population. This highlights the need to investigate other genetic, environmental, or epigenetic factors that may contribute to this condition. Future research should integrate advanced genomic techniques and broader analyses to better understand the aetiology of hypospadias.

Systematic identification of Y-chromosome gene functions in mouse spermatogenesis

The mammalian Y chromosome is essential for male fertility, but which Y genes regulate spermatogenesis is unresolved. We addressed this by generating 13 Y-deletant mouse models. In Eif2s3y, Uty, and Zfy2 deletants, spermatogenesis was impaired. We found that Uty regulates spermatogonial proliferation, revealed a role for Zfy2 in promoting meiotic sex chromosome pairing, and uncovered unexpected effects of Y genes on the somatic testis transcriptome. In the remaining single Y-gene deletants, spermatogenesis appeared unperturbed, but testis transcription was still altered. Multigene deletions, including a human-infertility AZFa model, exhibited phenotypes absent in single Y deletants. Thus, Y genes may regulate spermatogenesis even if they show no phenotypes when deleted individually. This study advances our knowledge of Y evolution and infertility and provides a resource to dissect Y-gene functions in other tissues.

A retrospective analysis of 1600 infertility patients with azoospermia and severe oligozoospermia

OBJECTIVE

This study aimed to investigate the genetic etiology of male infertility patients.

METHOD

A total of 1600 male patients with infertility, including 1300 cases of azoospermia and 300 cases of severe oligozoospermia, underwent routine semen analysis, chromosomal karyotype analysis and sex hormone level testing. The Azoospermia factor (AZF) on the Y chromosome was detected using the multiple fluorescence quantitative PCR technique. Additionally, copy number variation (CNV) analysis was performed on patients with Sertoli-cell-only syndrome who had a normal karyotype and AZF.

RESULT

Chromosomal abnormalities were found in 334 cases (20.88 %) of the 1600 male infertility patients. The most common type of abnormality was sex chromosome abnormalities (18.94 %), with 47, XXY being the most frequent abnormal karyotype. The rates of chromosomal abnormalities were significantly different between the azoospermia group and the severe oligospermia group (23.69 % and 8.67 %, respectively; P<0.05). AZF microdeletions were detected in 155 cases (9.69 %), with various deletion types and AZFc region microdeletion being the most prevalent. The rates of AZF microdeletions were not significantly different between the azoospermia group and the severe oligospermia group (9.15 % and 12 %, respectively; P=0.133). In 92 patients with Sertoli-cell-only syndrome who had a normal karyotype and AZF, the detection rate of CNV was 16.3 %. Compared to the severe oligospermia group, the azoospermia group had higher levels of FSH and LH and lower levels of T and E2, and the differences were statistically significant (P<0.05).

CONCLUSIONS

Male infertility is a complex multifactorial disease, with chromosomal abnormalities and Y chromosome microdeletions being important genetic factors leading to the disease. Initial genetic testing of infertile men should include karyotyping and Y chromosome microdeletions. If necessary, CNV testing should be performed to establish a clinical diagnosis and provide individualized treatment for male infertility.

A family with normal sperm motility carrying a sY86 deletion in AZFa region and partial deletion in AZFc region

Introduction

Usually, patients with sY84 or sY86 deficiency present with azoospermia, but recent studies have shown that some males with partial AZFa deletions, including sY84 or sY86, exhibit normal fertility. Here, we reported a rare case of AZF deletion in a family, where both father and son exhibited a deletion at the sY86 site in the AZFa region and a partial deletion in the AZFc region.

Methods and Results

Detection was performed using classical multiplex polymerase chain reaction and the "Male AZF Full-region Detection" Panel, revealing specific deletions in AZFa: Yq11.21 (14,607,372-14,637,973), 30.6 kb; AZFc: Yq11.223-11.23 (25,848,831-27,120,665), 1.3 M for the father; and Yq11.223-11.23 (25,505,378-27,120,665), 1.6 M for the son. Notably, although the son's sperm motility parameters showed no significant abnormalities, there was a history of failed pregnancies for twice, with sperm exhibiting a high rate of head defect.

Discussion

Given the complexities of the reproductive phenotype following AZF region deletions, additional extended genetic testing is necessary when partial deletions in the AZF region are detected, thus providing more accurate predictions of the spermatogenesis in patient. This study provides valuable insights and guidance for clinical decision-making and the implementation of assisted reproductive technologies in such cases.

Identification of deleterious variants associated with male infertility genes in a cohort of idiopathic hypospermatogenesis patients

Introduction

Hypospermatogenesis is a common histopathological subtype of non-obstructive azoospermia and is characterized by a decrease in the total number of germ cells within the seminiferous tubule as a result of spermatogenic failure. Determination of genetic factors before intracytoplasmic sperm injection can prevent the inheritance of these factors, as hypospermatogenesis patients gives high successful sperm retrieval rate. This study aimed to identify the structural variants associated with idiopathic hypospermatogenesis (iHS) by analyzing patient cohorts diagnosed with azoospermia using whole exome sequencing.

Methods

It is a hospital-based observational study in which patients reporting with azoospermia due to spermatogenic failure were recruited prospectively. Comprehensive clinical history, blood samples, semen analysis parameters, and reproductive endocrine evaluation reports of 51 hypospermatogenesis patients were collected. The known genetic causes were investigated using XY fluorescent in situ hybridization and Yq microdeletion for exclusion. Whole exome sequencing was performed, and the data of 42 iHS patients was analyzed to identify single nucleotide variants associated with diagnostically important male infertility genes.

Results

Genomic analysis of SNVs identified rare deleterious candidate variants in CFTR (c.1265C>T; p.Ser422Phe), CYP21A2 (c.955C>T; p.Gln319Glu), SRD5A2 (c.737G>A; p.Arg245Gln), LHCGR (c.378A>C; p.Lys126Asn) and AR (c.2179C>A; p.Arg727Ser) genes associated with 7/42 idiopathic hypospermatogenesis patients. In silico analysis of variants shows deleterious and probably damaging effects on canonical transcripts of the genes.

Discussion

This exploratory genomic analysis conducted on idiopathic hypospermatogenesis patients shows prevalence of rare deleterious candidate variants in genes associated with human male infertility. The candidate variants in idiopathic hypospermatogenesis patients are heterozygous and genotypically associated with syndromic male infertility. The symptomatic heterozygosity leading to mild spermatogenic failure resulting in hypospermatogenesis points towards a multifactorial etiology of the disease. This study justifies the importance of genetic screening of idiopathic hypospermatogenesis patients for the presence of structural variants in known human male infertility genes.

Phenotypic impact of CFTR mutations on male reproductive tract agenesis in a Chinese cohort with congenital absence of the vas deferens

PURPOSE

To investigate the genotype-phenotype correlations of cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations and their impact on male reproductive tract development in a cohort of Chinese patients with congenital absence of the vas deferens (CAVD).

METHODS

A total of 121 Chinese CAVD patients underwent genetic testing for CFTR and ADGRG2 mutations, semen analysis, scrotal and transrectal ultrasound examinations, and reproductive hormone measurements. The genotype-phenotype correlations were analyzed, focusing on the impact of CFTR variants on the presence or absence of the epididymis, vas deferens, seminal vesicles, and other related structures.

RESULTS

CFTR mutations were identified in 72.7% (88/121) of CAVD patients, with the IVS9-5 T variant being the most prevalent (54.5%, 66/121). Six novel CFTR variants (CFTR: L218Ffs*15, V1007Ffs*40, V938M, A566V, S605P, H949P) were identified in Chinese men. Patients with CFTR homozygous IVS9-5 T variants had a significantly lower rate of epididymal absence compared to those with one 5 T and one non-5 T variant or two non-5 T variants (p = 0.016). Notably, patients carrying at least one non-5 T variant were associated with an 8.17-fold increased risk of epididymal partial absence compared to those having the homozygous 5 T mutation (95% confidence interval 1.52-59.58, p = 0.009).

CONCLUSION

This study provides novel insights into the genotype-phenotype correlations of CFTR variants in Chinese CAVD patients, highlighting the differential impact of 5 T and non-5 T variants on male reproductive tract development. These findings provide additional information that may be helpful for genetic counseling, clinical management, and the development of personalized diagnostic and therapeutic strategies for CAVD patients.

Successful pregnancy after preimplantation genetic testing for structural rearrangements in a couple with complex chromosome rearrangement and recurrent in vitro fertilization failures: a case report

Objective

To present a case of a couple with 20 years of infertility and 10 recurrent in vitro fertilization (IVF) failures, identifying a paternal complex chromosome rearrangement using high-resolution karyotype together with preimplantation genetic testing for structural rearrangements (PGT-SR) and utilizing IVF-intracytoplasmic sperm injection to achieve a successful pregnancy.

Design

Case report.

Setting

Al Ain Fertility Center, Abu Dhabi, United Arab Emirates.

Patients

A 40-year-old male patient and a 37-year-old female patient with a history of infertility and recurrent IVF failures.

Exposure

In vitro fertilization-intracytoplasmic sperm injection with high-resolution karyotype and PGT-SR.

Main Outcome Measures

Identification of chromosomal abnormalities, successful embryo development, pregnancy outcome, and newborn karyotyping.

Results

Karyotyping revealed a paternal complex chromosome rearrangement, t(3;4;12) (q21;q33;q21), and a chromosomal polymorphism in the female (1qh+). In vitro fertilization-intracytoplasmic sperm injection with PGT-SR produced one euploid/balanced female embryo from 20 embryos across 8 cycles. The patient conceived after hormone replacement therapy and frozen embryo transfer, resulting in an uneventful, full-term pregnancy and delivery of a healthy baby via C-section. Newborn karyotyping was normal (46,XX).

Conclusion

High-resolution karyotype and PGT-SR should be offered to patients undergoing IVF, especially those with severe male factors, recurrent IVF failures, implantation failures, or recurrent pregnancy losses, to enhance the chances of a successful pregnancy.

The effect of male factors on embryo morphokinetics: a retrospective analysis of 2726 blastocysts

PURPOSE

Male infertility may influence fertilization rates, embryo morphology, and implantation rates in in vitro fertilization (IVF) cycles. Oocyte competence plays a major role in embryo development, but there is a limited understanding of the connection between sperm quality, embryo development, and morphokinetic parameters using donor oocytes. The study evaluated if sperm quality may influence the morphokinetic parameters in IVF cycles.

METHODS

A retrospective multicentric observational cohort study included 747 ICSI cycles using donor oocytes with fresh or frozen sperm. Embryos were cultured in time-lapse incubators until the blastocyst stage. The population was divided into three groups according to sperm concentration, as control group (> 16 mill/mL), severe oligospermia (0-5 mill/mL), and moderate oligospermia group (5-16 mill/mL).

RESULTS

Morphokinetic analysis showed no difference in the time from the 2-cell to 6-cell stage of embryo development. A significant difference was observed on day 3 of embryo development, specifically at the 7-cell stage (t7), severe oligospermia 53.37 ± 9.81, moderate oligospermia 56.95 ± 9.78, and control 55.1 ± 8.85 h post-insemination (hpi) (p = 0.024), and 8-cell stage (t8), severe oligospermia 55.41 ± 10.83, moderate oligospermia 61.86 ± 12.38 hpi (p < 0.001), and control 58.61 ± 11.33. Accordingly, the synchrony of the four cleavages going from 4 to 8 cells (s3) was found statistically different among the groups in the severe oligospermia 8.05 ± 9.99, moderate oligospermia 11.66 ± 11.04 hpi, and control 8.55 ± 8.58 (p = 0.009). Morphokinetic time ranges were obtained for t6, t7, t8, and s3 in order to identify the good-quality blastocysts.

CONCLUSIONS

Poor sperm quality is associated with alterations in morphokinetic parameters on day 3 in IVF cycles with donor oocytes, underlining the important role of spermatozoa during embryo development.

Advances in human In vitro spermatogenesis: A review

Recent advances surrounding in vitro spermatogenesis (IVS) have shown potential in creating a new paradigm of regenerative medicine in the future of fertility treatments for males experiencing non-obstructive azoospermia (NOA). Male infertility is a common condition affecting approximately 15% of couples, with azoospermia being present in 15% of infertile males (Cocuzza et al., 2013; Esteves et al., 2011a). Treatment for patients with NOA has primarily been limited to surgical sperm retrieval combined with in vitro fertilization intracytoplasmic sperm injection (IVF-ICSI); however, sperm retrieval is successful in only half of these patients, and live birth rates typically range between 10 and 25% (Aljubran et al., 2022). Therefore, a significant need exists for regenerative therapies in this patient population. IVS has been considered as a model for further understanding the molecular and cellular processes of spermatogenesis and as a potential regenerative therapeutic approach. While 2D cell cultures using human testicular cells have been attempted in previous research, lack of proper spatial arrangement limits germ cell differentiation and maturation, posing challenges for clinical application. Recent research suggests that 3D technology may have advantages for IVS due to mimicry of the native cytoarchitecture of human testicular tissue along with cell-cell communication directly or indirectly. 3D organotypic cultures, scaffolds, organoids, microfluidics, testis-on-a-chip, and bioprinting techniques have all shown potential to contribute to the technology of regenerative treatment strategies, including in vitro fertilization (IVF). Although promising, further work is needed to develop technology for successful, replicable, and safe IVS for humans. The intersection between tissue engineering, molecular biology, and reproductive medicine in IVS development allows for multidisciplinary involvement, where challenges can be overcome to realize regenerative therapies as a viable option.

Independent factors associated with intracytoplasmic sperm injection outcomes in patients with complete azoospermia factor c microdeletions

STUDY QUESTION

Which independent factors influence ICSI outcomes in patients with complete azoospermia factor c (AZFc) microdeletions?

SUMMARY ANSWER

In patients with complete AZFc microdeletions, the sperm source, male LH, the type of infertility in women, and maternal age are the independent factors associated with ICSI outcomes.

WHAT IS KNOWN ALREADY

AZF microdeletions are the second most prevalent factor contributing to infertility in men, with AZFc microdeletions being the most frequently affected locus, accounting for 60-70% of all cases. The primary clinical phenotypes are oligoasthenozoospermia and azoospermia in patients with complete AZFc microdeletions. These patients can achieve paternity through ICSI using either testicular (T-S) or ejaculated (E-S) spermatozoa. With aging in men with AZFc microdeletions, oligoasthenozoospermia or severe oligozoospermia may gradually progress to azoospermia.

STUDY DESIGN SIZE DURATION

In this retrospective cohort study, the independent factors associated with the outcomes of 634 ICSI cycles in 634 couples with the transfer of 1005 embryos between February 2015 and December 2023 were evaluated. The analysis included 398 ICSI cycles in 398 couples using E-S and 236 ICSI cycles in 236 couples using T-S; all men had complete AZFc microdeletions.

PARTICIPANTS/MATERIALS SETTING METHODS

The inclusion criteria were as follows: (i) men had complete AZFc microdeletions and (ii) the couple underwent ICSI treatment using T-S or E-S. The exclusion criteria were as follows: (i) cycles involving frozen-thawed oocytes; (ii) cycles in which all fresh embryos were frozen and not transferred; (iii) cycles lost to follow-up; and (iv) multiple ICSI cycles, apart from the first cycle for each couple. The primary outcome was the cumulative live birth rate per ICSI cycle, whereas the secondary outcomes were the clinical pregnancy rate per ICSI cycle, fertilization rate, and the no-embryo-suitable-for-transfer cycle rate (NESTR). Moreover, the maternal and neonatal outcomes were analyzed. Continuous variables showing non-normal distributions were expressed as median and interquartile range and were analyzed using the Kruskal-Wallis test. Categorical variables were expressed as percentages and were analyzed using the χ2 or Fisher's exact test. Linear and logistic regression models were constructed to assess the independent factors associated with ICSI outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

The T-S group exhibited inferior ICSI outcomes than the E-S group, marked by significantly reduced rates of cumulative live birth, clinical pregnancy, fertilization, high-quality embryos, blastocyst formation, and implantation, with higher NESTRs. However, the miscarriage rate and neonatal outcomes did not significantly differ between the groups. Multivariate linear regression analysis demonstrated that reduced fertilization rates were significantly associated with T-S use (adjusted β, -0.281; 95% CI, -0.332 to -0.229). Multivariate logistic regression demonstrated that increased NESTRs were significantly associated with T-S use (adjusted odds ratio (OR), 4.204; 95% CI, 2.340-7.691), along with uterine anomaly in women (adjusted OR, 2.853; 95% CI, 1.053-7.718), infertility in women with multiple etiologies (adjusted OR, 11.118; 95% CI, 2.034-66.508), and advanced maternal age (adjusted OR, 1.138; 95% CI, 1.029-1.263). The use of T-S (adjusted OR, 0.318; 95% CI, 0.188-0.528), uterine anomaly in women (adjusted OR, 0.263; 95% CI, 0.058-0.852), and increased maternal age (adjusted OR, 0.877; 95% CI, 0.801-0.958) were also associated with decreased clinical pregnancy rates per ICSI cycle. Likewise, lower cumulative live birth rates were associated with T-S use (adjusted OR, 0.273; 95% CI, 0.156-0.468), male LH levels (adjusted OR, 0.912; 95% CI, 0.837-0.990), uterine anomaly (adjusted OR, 0.101; 95% CI, 0.005-0.529), and increased maternal age (adjusted OR, 0.873; 95% CI, 0.795-0.958). No significant differences were observed in the maternal and neonatal outcomes between both groups.

LIMITATIONS REASONS FOR CAUTION

The study was based on a single-center, retrospective cohort design. The molecular diagnosis of AZFc microdeletions was reliant on loci sY254 and sY255 according to the European Academy of Andrology and European Molecular Genetics Quality Network guidelines. While our findings were based on the clinical phenotypes and laboratory parameters, the abnormalities in the genetic profiles of spermatogenesis and early embryonic development in patients between the T-S and E-S groups have not yet been elucidated.

WIDER IMPLICATIONS OF THE FINDINGS

Our results offer important insights into the independent factors that influence ICSI outcomes in patients with complete AZFc microdeletions. ICSI using E-S is a more favorable therapeutic option for younger patients with AZFc microdeletions and with sperm present in their ejaculate. This study highlights a new direction to investigate the molecular and phenotypic differences between the T-S and E-S groups, which may contribute to the diagnosis and treatment of complete AZFc microdeletions.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by Capital's Funds for Health Improvement and Research (2022-2-4094), Beijing Natural Science Foundation (7232203, 7242164), National Key Research and Development Program (2021YFC2700200, 2023YFC2705600), National Natural Science Foundation of China (82301889), Peking University Third Hospital Innovation Transformation Fund (BYSYZHKC2023103), Peking University Third Hospital Clinical Cohort Construction Project (BYSYDL2023016), and Young Elite Scientists Sponsorship Program by CAST (2023QNRC001). None of the authors have any competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Relationship Between Loss of Y Chromosome and Urologic Cancers: New Future Perspectives

Background: The Y chromosome (ChrY) is essential for male sex determination and spermatogenesis. However, recent studies have revealed its broader role in various physiological processes and disease susceptibility, including cancer. Methods: A comprehensive literature review was conducted using databases like MEDLINE, Scopus, Web of Science, and Google Scholar. The review included clinical and preclinical studies in animals and humans focusing on the role of LoY in urological tumors. Data on the frequency of LoY, its clinical implications, and underlying mechanisms were extracted and analyzed. Results: The evidence suggests that LoY is associated with an increased risk of urologic neoplasms, potentially serving as an early marker of genomic instability. Studies reveal that LoY in urologic cancers correlates with worse survival outcomes and may contribute to tumor progression. LoY may interfere with chromatin structure and epigenetic regulation, suggesting its role as a contributor to early tumorigenesis. Conclusions: LoY appears to be a structural aberration with unique biological and clinical relevance in urologic cancers, possibly serving as a biomarker for genomic instability. Further research is necessary to identify specific Y-linked genes affected by LoY, potentially informing targeted therapies and early diagnostic strategies for these cancers.

Prevalence of AZFс Y chromosome microdeletions and association with spermatogenesis in Russian men from the general population

The Y chromosome contains a set of genes with testis-specific expression that are responsible for the development of testes and spermatogenesis, and it is the most important target in the search for genetic causes of male infertility. Most of these genes are located in the "azoospermia factor" AZF locus (regions AZFa, AZFb, and AZFc) on the long arm of the Y chromosome. Microdeletions of the Y chromosome, leading to the removal of the entire AZF locus as well as one or more regions (complete deletions), are one of the leading causes of spermatogenesis impairment and infertility. However, the role of partial AZFc deletions (gr/gr, b2/b3, b1/b3) in spermatogenesis failure is unclear, and their impact on spermatogenesis varies between populations. The aim of the present study was to assess the frequency of various types of AZFc microdeletions and to search for associations with spermatogenesis parameters in men of Slavic ethnicity from the general Russian population (n = 700, average age 25.8 years). To identify AZF microdeletions, the presence/absence of 15 STS markers was analyzed using multiplex real-time polymerase chain reaction. Age, weight, height, and the volume, concentration, total count, proportion of motile and morphologically normal spermatozoa in the ejaculate were recorded for all participants. In the studied sample, 19.9 % (139/700) of men were found to have AZFc microdeletions, of which 16.7 % (117/700) were carriers of a partial b2/b3 deletion, 3.0 % (21/700) had a partial gr/gr deletion, and 0.14 % (1/700) had a complete b2/b4 deletion. Neither AZFa nor AZFb microdeletions nor other types of AZF deletions were detected. The overall frequency of all types of AZFc deletions, as well as each type of partial microdeletion, b2/ b3 and gr/gr, did not differ in the groups of azoospermia, severe oligozoospermia (≤5.0 mill/ml), oligozoospermia (5.0 < SC <16.0 mill/ml), and normal sperm concentration (≥16.0 mill/ml). Comparison of semen parameters in groups with different types of partial AZFc deletions and the control group (without deletions) also did not reveal significant differences. Thus, partial AZFc microdeletions b2/b3 and gr/gr do not have a significant impact on spermatogenesis in Slavic men. It is suggested that in Slavs, partial AZFc microdeletions b2/b3 and gr/gr are fixed in Y haplogroups N3 and R1a, respectively, and their negative impact on spermatogenesis is balanced by other genetic factors. The higher frequency of partial AZFc deletions (19.7 %) in Slavs compared to European populations (7.3 %) established in our study may be explained by the widespread distribution of these Y haplogroups in the Slavic population of Russia.

MTHFR C677T、MTHFR A1298C、MTRR A66G and MTR A2756G polymorphisms and male infertility risk: a systematic review and meta-analysis

BACKGROUND

Epidemiological studies have reported that polymorphisms of folate-metabolizing genes have a significant impact on male infertility. However, the results of published studies have come to different conclusions.

OBJECTIVE

To determine an association between folate-metabolizing gene polymorphisms and the risk of male infertility.

METHODS

The meta-analysis was conducted according to the PRISMA 2020 statement. The protocol was registered with PROSPERO (CRD42023412251). Studies were searched from PubMed, Google Scholar, Embase, Scopus, and the Cochrane Library up to 24st October2023. Articles that satisfied the inclusion criteria were evaluated for their quality using the Newcastle-Ottawa Scale. Data were extracted from the eligible studies and were analyzed for pooled up odds ratio (OR) with 95% confidence interval (CI). Meta-analysis was conducted using STATA 12.

RESULTS

Forty-six case-control studies were included in the meta-analysis which comprised 20,639 participants. The pooled analysis revealed that the MTHFR C677T polymorphism was significantly associated with male infertility and abnormospermia.Three-fifths of the model showed there was a significant association between the MTR A2756G polymorphism and male infertility. Both MTHFR A1298C and MTRR A66G polymorphisms were not significantly associated with male fertility. Furthermore, subgroup analysis revealed a significant association between the MTHFR C677T polymorphism and male fertility in Asian countries.

CONCLUSION

This meta-analysis suggests that the MTHFR C677T and MTR A2756G polymorphisms may be a potential risk factor for male infertility.

Clinical Analysis of Y Chromosome Microdeletions and Chromosomal Aberrations in 1596 Male Infertility Patients of the Zhuang Ethnic Group in Guangxi

The long arm of the Y chromosome (Yq) contains many amplified and palindromic sequences that are prone to self-reorganization during spermatogenesis, and tiny submicroscopic segmental deletions in the proximal Yq are called Y chromosome microdeletions (YCM). A retrospective study was conducted on male infertility patients of Zhuang ethnicity who presented at Reproductive Medical Center of Nanning between January 2015 and May 2023. Seminal fluid was collected for standard examination. YCM were detected by using a combination of multiplex PCR and agarose gel electrophoresis. Preparation of peripheral blood chromosomes and karyotyping of chromosomes was performed. 147 cases (9.22%) of YCM were detected in 1596 male infertility patients of Zhuang ethnicity. Significant difference was found in the detection rate of YCM between the azoospermia group and the oligospermia group (P < 0.001). Of all types of YCM, the highest detection rate was AZFc (n = 83), followed by AZFb + c (n = 28). 264 cases (16.54%) of sex chromosomal aberrations were detected. The most prevalent karyotype was 47, XXY (n = 202). The detection rate of sex chromosomal aberrations in azoospermia group was higher than that in severe oligospermia group and oligospermia group, and the differences were significant (P < 0.001). 28 cases (1.57%) of autosomal aberrations and 105 cases (6.58%) of chromosomal polymorphism were identified. The current research has some limitations due to the lack of normal men as the control group but suggests that YCM and chromosomal aberrations represent key genetic factors influencing spermatogenesis in infertile males of Zhuang ethnicity in Guangxi.

Screening of the Combined Risk of Genetics and Epidemiology on Infertility Among Indian Men: Synergistic Effect of AZFc Partial Deletions and Habits of Smokeless Chewing Tobacco

The AZFc partial deletions of Y chromosome and lifestyle/epidemiological factors such as the use of smokeless chewing tobacco (SCT) exhibit intriguing variations in their association with male infertility across the population, ethnicity, and genetic background. Here, a pioneering attempt has been made to elucidate the interactions of such deletions with the habits of SCT consumption among the participating individuals, using their large epidemiological data. This screening program was conducted among Bengali-speaking men in West Bengal, India. We screened the prevalence and association of distinct partial deletions (gr/gr, b1/b3, and b2/b3) of the AZFc region using locus-specific sequence-tagged site (STS) markers among 728 case subjects and compared them with 264 ethnicity- and age-matched proven-fertile control men. The recorded epidemiological data of the study group and the outcome of partial deletion analysis were compiled to frame the plausible Gene × Epidemiological factor (G × E) interactions. The gr/gr deletion was reported to be significantly associated with azoospermic (p = .0015, odds ratio [OR] = 3.413) and oligozoospermic (p = .0382, OR = 3.012) case subgroups, and b1/b3 deletions were also detected among the infertile persons only. The G × E model revealed that men who carried microdeletions as well as were SCT users had an elevated risk of infertility (p = .002, OR = 6.38). The study highlights the fact that AZFc partial deletions and SCT, when co-occurred, synergistically increase the risk of infertility among men. This work helps to get more insight into the etiology of male infertility in the light of gene-environmental interaction.

Non-Obstructive Azoospermia and Intracytoplasmic Sperm Injection: Unveiling the Chances of Success and Possible Consequences for Offspring

Non-obstructive azoospermia (NOA) is found in up to 15% of infertile men. While several causes for NOA have been identified, the exact etiology remains unknown in many patients. Advances in assisted reproductive technology, including intracytoplasmic sperm injection (ICSI) and testicular sperm retrieval, have provided hope for these patients. This review summarizes the chances of success with ICSI for NOA patients and examines preoperative factors and laboratory techniques associated with positive outcomes. Furthermore, we reviewed possible consequences for offspring by the use of ICSI with testicular sperm retrieved from NOA patients and the interventions that could potentially mitigate risks. Testicular sperm retrieved from NOA patients may exhibit increased chromosomal abnormalities, and although lower fertilization and pregnancy rates are reported in NOA patients compared to other forms of infertility, the available evidence does not suggest a significant increase in miscarriage rate, congenital malformation, or developmental delay in their offspring compared to the offspring of patients with less severe forms of infertility or the offspring of fertile men. However, due to limited data, NOA patients should receive specialized reproductive care and personalized management. Counseling of NOA patients is essential before initiating any fertility enhancement treatment not only to mitigate health risks associated with NOA but also to enhance the chances of successful outcomes and minimize possible risks to the offspring.

An association weight matrix identified biological pathways associated with bull fertility traits in a multi-breed population

Using seven indicator traits, we investigated the genetic basis of bull fertility and predicted gene interactions from SNP associations. We used percent normal sperm as the key phenotype for the association weight matrix-partial correlation information theory (AWM-PCIT) approach. Beyond a simple list of candidate genes, AWM-PCIT predicts significant gene interactions and associations for the selected traits. These interactions formed a network of 537 genes: 38 genes were transcription cofactors, and 41 genes were transcription factors. The network displayed two distinct clusters, one with 294 genes and another with 243 genes. The network is enriched in fertility-associated pathways: steroid biosynthesis, p53 signalling, and the pentose phosphate pathway. Enrichment analysis also highlighted gene ontology terms associated with 'regulation of neurotransmitter secretion' and 'chromatin formation'. Our network recapitulates some genes previously implicated in another network built with lower-density genotypes. Sequence-level data also highlights additional candidate genes relevant to bull fertility, such as FOXO4, FOXP3, GATA1, CYP27B1, and EBP. A trio of regulatory genes-KDM5C, LRRK2, and PME-was deemed core to the network because of their overarching connections. This trio probably influences bull fertility through their interaction with genes, both known and unknown as to their role in male fertility. Future studies may target the trio and their target genes to enrich our understanding of male fertility further.

Kinship analysis and pedigree reconstruction by RAD sequencing in cattle

Kinship and pedigree, used for estimating inbreeding, heritability, selection, and gene flow, are useful for breeding and animal conservation. However, as the size of crossbred populations increases, inaccurate generation and parentage assignment in livestock farms increase. Restriction-site-associated DNA sequencing is a cost-effective platform for single nucleotide polymorphism (SNP) discovery and genotyping. Here, we performed a kinship analysis and pedigree reconstruction for Angus and Xiangxi yellow cattle. A total of 975 cattle, including 923 offspring with 24 known sires and 28 known dams, were sampled and subjected to SNP discovery and genotyping. The identified SNP panel included 7,305 SNPs capturing the maximum difference between paternal and maternal genome information, allowing us to distinguish F1 from F2 generations with 90% accuracy. In conclusion, we provided a low-cost and efficient SNP panel for kinship analyses and the improvement of local genetic resources, which are valuable for breed improvement, local resource utilization, and conservation.

Sestrin2 and Sestrin3 protect spermatogenesis against heat-induced meiotic defects†

Heat stress induces testicular oxidative stress, impairs spermatogenesis, and increases the risk of male infertility. Recent studies have highlighted the antioxidative properties of the Sestrins family in reducing cellular oxidative damage. However, the role of Sestrins (Sestrin1, 2, and 3) in the testicular response to heat stress remains unclear. Here, we found that Sestrin2 and 3 were highly expressed in the testis relative to Sestrin1. Then, the Sestrin2-/- and Sestrin3-/- mice were generated by CRISPR/Cas9 to investigate the role of them on spermatogenesis after heat stress. Our data showed that Sestrin2-/- and Sestrin3-/- mice testes exhibited more severe damage manifested by exacerbated loss of germ cells and higher levels of oxidative stress as compared to wild-type counterparts after heat stress. Notably, Sestrin2-/- and Sestrin3-/- mice underwent a remarkable increase in heat-induced spermatocyte apoptosis than that of controls. Furthermore, the transcriptome landscape of spermatocytes and chromosome spreading showed that loss of Sestrin2 and Sestrin3 exacerbated meiotic failure by compromising DNA double-strand breaks repair after heat stress. Taken together, our work demonstrated a critical protective function of Sestrin2 and Sestrin3 in mitigating the impairments of spermatogenesis against heat stress.

Sperm retrieval rate and patient factors in azoospermia factor c microdeletion azoospermia: a systematic review

OBJECTIVE

To reveal the overall sperm retrieval rate (SRR) and range in patients with azoospermia factor c (AZFc) microdeletion azoospermia by microdissection testicular sperm extraction (mTESE) and discuss the differences of preoperative patient factors among studies with various SRRs.

PATIENTS AND METHODS

We searched PubMed, Web of Science and Embase until February 2023. All studies reporting SRRs by mTESE and required parameters of patients with AZFc microdeletions were included. The primary outcome was the SRR and, if available, the pregnancy rate (PR) and live-birth rate (LBR) after intracytoplasmic sperm injection were also investigated as secondary outcomes.

RESULTS

Eventually 11 cohort studies were included in this review. A total number of 441 patients underwent mTESE and in 275 of them sperm was obtained, reaching an overall SRR of 62.4%. The SRRs among studies had a wide range from 25.0% to 85.7%. The studies reporting higher SRRs generally had older mean ages, and higher follicle-stimulating hormone and testosterone levels. Only four studies provided practical data on pregnancies and live-born children of patients with AZFc microdeletions, so the overall PR and LBR were unavailable.

CONCLUSIONS

The overall SRR of patients with AZFc microdeletion azoospermia was 62.4%. The effect of patient factors in SR needs further evidence in future work.

Detection of AZF microdeletions and analysis of reproductive hormonal profiles in Hainan men undergoing assisted reproductive technology

BACKGROUND

Male infertility has become a global health problem, and genetic factors are one of the essential causes. Y chromosome microdeletion is the leading genetic factor cause of male infertility. The objective of this study is to investigate the correlation between male infertility and Y chromosome microdeletions in Hainan, the sole tropical island province of China.

METHODS

We analyzed the semen of 897 infertile men from Hainan in this study. Semen analysis was measured according to WHO criteria by professionals at the Department of Reproductive Medicine, the First Affiliated Hospital of Hainan Medical University, where samples were collected. Y chromosome AZF microdeletions were confirmed by detecting six STS markers using multiple polymerase chain reactions on peripheral blood DNA. The levels of reproductive hormones, including FSH, LH, PRL, T, and E2, were quantified using the enzyme-linked immunosorbent assay (ELISA).

RESULTS

The incidence of Y chromosome microdeletion in Hainan infertile men was 7.13%. The occurrence rate of Y chromosome microdeletion was 6.69% (34/508) in the oligozoospermia group and 7.71% (30/389) in the azoospermia group. The deletion of various types in the AZF subregion was observed in the group with azoospermia, whereas no AZFb deletion was detected in the oligozoospermia group. Among all patients with microdeletions, the deletion rate of the AZFc region was the higher at 68.75% (44 out of 64), followed by a deletion rate of 6.25% (4 out of 64) for the AZFa region and a deletion rate of 4.69% (3 out of 64) for the AZFb region. The deletion rate of the AZFa region was significantly higher in patients with azoospermia than in patients with oligozoospermia (0.51% vs. 0.39%, p < 0.001). In comparison, the deletion rate of the AZFc region was significantly higher in patients with oligozoospermia (3.08% vs. 6.30%, p < 0.001). Additionally, the AZFb + c subregion association deletion was observed in the highest proportion among all patients (0.89%, 8/897), followed by AZFa + b + c deletion (0.56%, 5/897), and exclusively occurred in patients with azoospermia. Hormone analysis revealed FSH (21.63 ± 2.01 U/L vs. 10.15 ± 0.96 U/L, p = 0.001), LH (8.96 ± 0.90 U/L vs. 4.58 ± 0.42 U/L, p < 0.001) and PRL (263.45 ± 21.84 mIU/L vs. 170.76 ± 17.10 mIU/L, p = 0.002) were significantly increased in azoospermia patients with microdeletions. Still, P and E2 levels were not significantly different between the two groups.

CONCLUSIONS

The incidence of AZF microdeletion can reach 7.13% in infertile men in Hainan province, and the deletion of the AZFc subregion is the highest. Although the Y chromosome microdeletion rate is distinct in different regions or populations, the regions mentioned above of the Y chromosome may serve an indispensable role in regulating spermatogenesis. The analysis of Y chromosome microdeletion plays a crucial role in the clinical assessment and diagnosis of male infertility.

Optimization of Multiplex-PCR Technique To Determine Azf Deletions in infertility Male Patients

Background

To optimize the multiplex polymerase chain reaction (M-PCR) technique to diagnose microdeletions of azoospermia factors (AZF) on the Y chromosome and initially apply the technique to diagnose male patients with sperm density less than 5×106 million sperm/mL was assigned to do a test to check for AZF microdeletions on the Y chromosome.

Methods

Based on the positive control samples which belong to male subjects who have had 2 healthy children without any assisted reproductive technologies, the M-PCR method was developed to detect simultaneously and accurately AZF microdeletions on 32 male patients with sperm densities below 5×106 million sperm/mL of semen at the Department of Biology and Medical Genetics - Vietnam Military Medical University.

Results

Successful optimization of the M-PCR technique including 7 reactions arranged according to each AZFabc region using 24 STS/gene on the Y chromosome. Initial application to diagnose AZF deletion on 32 azoospermic and oligospermic men reveals that AZFa deletion accounts for 6.25% (2/32); deletion of all 3 regions AZFa,b,c with 18.75% (6/32 cases); The combined deletion rate of AZFb,c is highest, accounting for 56.24% (18/32 patients).

Conclusion

Successfully optimized the M-PCR technique in identifying AZF microdeletions using 24 sequence tagged sites (STS)/gene for azoospermic and oligozoospermic men. The M-PCR technique has great potential in the application of AZF deletion diagnosis.

Etiology of Male Infertility: an Update

Spermatogenesis is a complex process of germ cell division and differentiation that involves extensive cross-talk between the developing germ cells and the somatic testicular cells. Defective endocrine signaling and/or intrinsic defects within the testes can adversely affect spermatogenic progression, leading to subfertility/infertility. In recent years, male infertility has been recognized as a global public health concern, and research over the last few decades has elucidated the complex etiology of male infertility. Congenital reproductive abnormalities, genetic mutations, and endocrine/metabolic dysfunction have been demonstrated to be involved in infertility/subfertility in males. Furthermore, acquired factors like exposure to environmental toxicants and lifestyle-related disorders such as illicit use of psychoactive drugs have been shown to adversely affect spermatogenesis. Despite the large body of available scientific literature on the etiology of male infertility, a substantial proportion of infertility cases are idiopathic in nature, with no known cause. The inability to treat such idiopathic cases stems from poor knowledge about the complex regulation of spermatogenesis. Emerging scientific evidence indicates that defective functioning of testicular Sertoli cells (Sc) may be an underlying cause of infertility/subfertility in males. Sc plays an indispensable role in regulating spermatogenesis, and impaired functional maturation of Sc has been shown to affect fertility in animal models as well as humans, suggesting abnormal Sc as a potential underlying cause of reproductive insufficiency/failure in such cases of unexplained infertility. This review summarizes the major causes of infertility/subfertility in males, with an emphasis on infertility due to dysregulated Sc function.

Disruption of the Uty epigenetic regulator locus in hematopoietic cells phenocopies the profibrotic attributes of Y chromosome loss in heart failure

Heart failure affects millions of people worldwide, with men exhibiting a higher incidence than women. Our previous work has shown that mosaic loss of the Y chromosome (LOY) in leukocytes is causally associated with an increased risk for heart failure. Here, we show that LOY macrophages from the failing hearts of humans with dilated cardiomyopathy exhibit widespread changes in gene expression that correlate with cardiac fibroblast activation. Moreover, we identify the ubiquitously transcribed t et ratricopeptide Y-linked (Uty) gene in leukocytes as a causal locus for an accelerated progression of heart failure in male mice with LOY. We demonstrate that Uty disruption leads to epigenetic alterations in both monocytes and macrophages, increasing the propensity of differentiation into profibrotic macrophages. Treatment with a transforming growth factor-β-neutralizing antibody prevented the cardiac pathology associated with Uty deficiency in leukocytes. These findings shed light on the mechanisms that contribute to the higher incidence of heart failure in men.

Association of Urinary Mycotoxins with Sperm Quality: A Case-Control Study in Southern Nigeria

The objective of this study was to determine the association between mycotoxins and the quality of spermatozoa in Nigeria. We designed a prospective case-control study involving 136 men diagnosed with reduced sperm count and quality in five infertility clinics in southwest Nigeria and 154 normal fertile controls. Sperm analysis was conducted in accordance with the recommendations of the World Health OrganizationWHO, while Liquid Chromatography-Mass Spectrometry was used to assay three metabolites of mycotoxins (zearalenone, ochratoxin A, and deoxyvinelol) in the urine samples of cases and controls. The data were analysed with descriptive statistics and non-parametric linear regression. The results showed no overall significant difference in levels of these metabolites between the cases and control groups. In contrast, higher levels of zearalenone and ochratoxin A significantly decreased sperm motility in the cases. Similarly, an increase in the level of ochratoxin A decreased sperm morphology in the unadjusted model in the cases. We conclude that exposure to mycotoxins reduces the quality of spermatozoa (motility and morphology) in Nigerian men but may have no effect on sperm count. Efforts to reduce the exposure of men to mycotoxins are important interventions to improve sperm quality and reduce the prevalence of male infertility in the country.

Comparative Bioinformatic Analysis of the Proteomes of Rabbit and Human Sex Chromosomes

Studying proteins associated with sex chromosomes can provide insights into sex-specific proteins. Membrane proteins accessible through the cell surface may serve as excellent targets for diagnostic, therapeutic, or even technological purposes, such as sperm sexing technologies. In this context, proteins encoded by sex chromosomes have the potential to become targets for X- or Y-chromosome-bearing spermatozoa. Due to the limited availability of proteomic studies on rabbit spermatozoa and poorly annotated databases for rabbits compared to humans, a bioinformatic analysis of the available rabbit X chromosome proteome (RX), as well as the human X (HX) and Y (HY) chromosomes proteome, was conducted to identify potential targets that could be accessible from the cell surface and predict which of the potential targets identified in humans might also exist in rabbits. We identified 100, 211, and 3 proteins associated with the plasma membrane or cell surface for RX, HX, and HY, respectively, of which 61, 132, and 3 proteins exhibit potential as targets as they were predicted to be accessible from the cell surface. Cross-referencing the potential HX targets with the rabbit proteome revealed an additional 60 proteins with the potential to be RX targets, resulting in a total of 121 potential RX targets. In addition, at least 53 possible common HX and RX targets have been previously identified in human spermatozoa, emphasizing their potential as targets of X-chromosome-bearing spermatozoa. Further proteomic studies on rabbit sperm will be essential to identify and validate the usefulness of these proteins for application in rabbit sperm sorting techniques as targets of X-chromosome-bearing spermatozoa.

Molecular and Functional Characterization of Human Sex-Determining Region on the Y Chromosome Variants Using Protamine 1 Promoter

The male sex-determining gene, sex-determining region on the Y chromosome (SRY), is expressed in adult testicular germ cells; however, its role in regulating spermatogenesis remains unclear. The role of SRY in the postmeiotic gene expression was investigated by determining the effect of SRY on the promoter of the haploid-specific Protamine 1 (PRM1) gene, which harbors five distinct SRY-binding motifs. In a luciferase reporter assay system, SRY upregulates PRM1 promoter activity in vitro in a dose-dependent manner. Through a gel-shift assay involving a 31-bp DNA fragment encompassing the SRY element within the PRM1 promoter, the third SRY-binding site on the sense strand (-373/-367) was identified as crucial for PRM1 promoter activation. This assay was extended to analyze 9 SRY variants found in the testicular DNA of 44 azoospermia patients. The findings suggest that SRY regulates PRM1 promoter activity by directly binding to its specific motif within the PRM1 promoter.

Azoospermia factor c microdeletions and outcomes of assisted reproductive technology: a systematic review and meta-analysis

OBJECTIVE

To investigate whether Azoospermia Factor c (AZFc) microdeletions affect Assisted Reproductive Technology (ART) outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENTS

Infertile men with and without AZFc microdeletions.

INTERVENTION(S)

Electronic databases were searched for case-control studies reporting sperm retrieval rates and outcomes of ART in infertile men with and without AZFc microdeletions from inception to April 2023. Study quality was assessed using the Newcastle-Ottawa Scale. Summary effect sizes (odds ratio [OR] with 95% confidence interval [CI]) were calculated for both categories of infertile men.

MAIN OUTCOME MEASURES

The primary outcome was successful sperm retrieval and the secondary outcomes were outcomes of ART.

RESULTS

Case-control studies reporting sperm retrieval rates and ART outcomes in men with AZFa and AZFb deletions were unavailable. On the basis of the data from 3,807 men, sperm retrieval rates were found to be higher in men with AZFc microdeletions compared to their non-deleted counterparts [OR = 1.82, 95% CI 0.97, 3.41], but the difference was not statistically significant. A significantly lower fertilization rate (OR = 0.61, 95% CI [0.50, 0.74]), clinical pregnancy rate (OR = 0.61, 95% CI [0.42, 0.89]), and live birth rate (OR = 0.54, 95% CI [0.40, 0.72]) were observed in men with AZFc deletions compared with men without deletions. There was no statistically significant difference in rates of embryo cleavage, blastocyst formation, good-quality embryos, implantation, and miscarriage between the two groups. On correcting for female factors, the fertilization rate (OR = 0.76, 95% CI [0.71, 0.82]), cleavage rate (OR = 0.54, 95% CI [0.41, 0.72]), clinical pregnancy rate (OR = 0.39, 95% CI [0.30, 0.52]), and live birth rate (OR = 0.48, 95% CI [0.35, 0.65]) were significantly lower in men with AZFc deletions compared with controls.

CONCLUSIONS

Presence of AZFc microdeletions adversely affects outcomes of ART in infertile men. Further in-depth studies delineating the role of the AZF genes in embryonic development are necessary to understand the full-impact of this finding.

CLINICAL TRIAL REGISTRATION NUMBER

CRD42022311738.

Environmental and Genetic Traffic in the Journey from Sperm to Offspring

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

Y-chromosome haplogroups and Azoospermia Factor (AZF) analysis in Tunisian infertile male

The aim of the present study was to clarify the implication of Y chromosome genetic variations and haplogroups in Tunisian infertile men. A total of 27 Y-chromosomal binary markers partial microdeletions (gr/gr, b1/b3 and b2/b3) and copy number variation of DAZ and CDY genes in the AZFc region were analysed in 131 Tunisian infertile men with spermatogenic failure and severe reduced sperm concentrations and in 85 normospermic men as controls. Eleven different haplogroups in the overall population study (E3b2; J1J*, E1, E3b*, F, G, K, P/Q, R*, R1* and R1a1) were found. Interestingly, the J1J* haplogroup was significantly more frequent in azoo/oligospermic patients than in normospermic men (35.1% and 22.3%, respectively (p value = 0.04)). Results showed also that patients without DAZ/CDY1 copies loss and without partial microdeletions belonged to the R1 haplogroup. The relative high frequencies of two haplogroups, E3b2 (35.1%) and J (30%) was confirmed in Tunisia. We reported in the present study and for the first time, that J1J* haplogroup may confer a risk factor for infertility in the Tunisian population and we suggested that R1 haplogroup may ensure certain stability to Y-chromosome in Tunisian men.

Polymorphisms and expression levels of TNP2, SYCP3, and AZFa genes in patients with azoospermia

OBJECTIVE

Azoospermia (the total absence of sperm in the ejaculate) affects approximately 10% of infertile males. Despite diagnostic advances, azoospermia remains the most challenging issue associated with infertility treatment. Our study evaluated transition nuclear protein 2 (TNP2) and synaptonemal complex protein 3 (SYCP3) polymorphisms, azoospermia factor a (AZFa) microdeletion, and gene expression levels in 100 patients with azoospermia.

METHODS

We investigated a TNP2 single-nucleotide polymorphism through polymerase chain reaction (PCR) restriction fragment length polymorphism analysis using a particular endonuclease. An allele-specific PCR assay for SYCP3 was performed utilizing two forward primers and a common reverse primer in two PCR reactions. Based on the European Academy of Andrology guidelines, AZFa microdeletions were evaluated by multiplex PCR. TNP2, SYCP3, and the AZFa region main gene (DEAD-box helicase 3 and Y-linked [DDX3Y]) expression levels were assessed via quantitative PCR, and receiver operating characteristic curve analysis was used to determine the diagnostic capability of these genes.

RESULTS

The TNP2 genotyping and allelic frequency in infertile males did not differ significantly from fertile volunteers. In participants with azoospermia, the allelic frequency of the SYCP3 mutant allele (C allele) was significantly altered. Deletion of sY84 and sY86 was discovered in patients with azoospermia and oligozoospermia. Moreover, SYCP3 and DDX3Y showed decreased expression levels in the azoospermia group, and they exhibited potential as biomarkers for diagnosing azoospermia (area under the curve, 0.722 and 0.720, respectively).

CONCLUSION

These results suggest that reduced SYCP3 and DDX3Y mRNA expression profiles in testicular tissue are associated with a higher likelihood of retrieving spermatozoa in individuals with azoospermia. The homozygous genotype TT of the SYCP3 polymorphism was significantly associated with azoospermia.

Advanced isolation, expansion and characterization research study on pig testicular cells during differentiation and proliferation

Spermatogenesis is the complex process of sperm production to transmit paternal genetic information to the subsequent generation. This process is determined by the collaboration of several germ and somatic cells, most importantly spermatogonia stem cells and Sertoli cells. To characterize germ and somatic cells in the tubule seminiferous contort in pig and consequently has an impact on the analysis of pig fertility. Germ cells were extracted from pig testis by enzymatic digestion before being expanded on Sandos inbred mice (SIM) embryo-derived thioguanine and ouabain resistant fibroblasts (STO) feeder layer supplemented with FGF, EGF, and GDNF. Immunohistochemistry (IHC) and immunocytochemistry (ICC) analysis for Sox9, Vimentin, and PLZF markers were performed to examine the generated colonies of pig testicular cells. Electron microscopy was also utilized to analyze the morphological features of the extracted pig germ cells. IHC analysis revealed that Sox9 and Vimentin were expressed in the basal compartment of the seminiferous tubules. Moreover, ICC results showed that the cells have low expression of PLZF while expressing Vimentin. The heterogeneity of the in vitro cultured cells was detected via morphological analysis by the electron microscope. In this experimental study, we tried to reveal exclusive information which obviously could be helpful for future success in the achievement of proper therapies against infertility and sterility as an important global issue.

DNA Profiling in Human Identification: From Past to Present

Forensic DNA typing has been widely accepted in the courts all over the world. This is because DNA profiling is a very powerful tool to identify individuals on the basis of their unique genetic makeup. DNA evidence is capable of not only identifying the presence of specific biospecimens in a crime scene, but it is also used to exonerate suspects who are innocent of a crime. Technological advancements in DNA profiling, including the development of validated kits and statistical methods have made this tool to be more precise in forensic investigations. Therefore, validated combined DNA index system (CODIS) short tandem repeats (STRs) kits which require very small amount of DNA, coupled with real-time polymerase chain reaction (PCR) and the statistical strengths are used routinely to identify human remains, establish paternity or to match suspected crime scene biospecimens. The road to modern DNA profiling has been long, and it has taken scientists decades of work and fine tuning to develop highly accurate testing and analyses that are used today. This review will discuss the various DNA polymorphisms and their utility in human identity testing.

From Diagnosis to Treatment: Comprehensive Care by Reproductive Urologists in Assisted Reproductive Technology

Infertility is a global health concern, with male factors playing an especially large role. Unfortunately, however, the contributions made by reproductive urologists in managing male infertility under assisted reproductive technology (ART) often go undervalued. This narrative review highlights the important role played by reproductive urologists in diagnosing and treating male infertility as well as any barriers they face when providing services. This manuscript presents a comprehensive review of reproductive urologists' role in managing male infertility, outlining their expertise in diagnosing and managing male infertility as well as reversible causes and performing surgical techniques such as sperm retrieval. This manuscript investigates the barriers limiting urologist involvement such as limited availability, awareness among healthcare professionals, and financial constraints. This study highlights a decrease in male fertility due to lifestyle factors like sedentary behavior, obesity, and substance abuse. It stresses the significance of conducting an evaluation process involving both male and female partners to identify any underlying factors contributing to infertility and to identify patients who do not require any interventions beyond ART. We conclude that engaging urologists more effectively in infertility management is key to optimizing fertility outcomes among couples undergoing assisted reproductive technology treatments and requires greater education among healthcare providers regarding the role urologists and lifestyle factors that could have an effect on male fertility.

Cigarette smoke-induced injury induces distinct sex-specific transcriptional signatures in mice tracheal epithelial cells

The airway epithelial barrier is crucial for defending against respiratory insults and diseases. Disruption of epithelial integrity contributes to respiratory diseases, and sex-specific differences in susceptibility and severity have been observed. However, sex-specific differences in the context of respiratory diseases are often overlooked, especially in murine models. In this study, we investigated the in vitro transcriptomics of male and female murine tracheal epithelial cells (mTECs) in response to chronic cigarette smoke (CS) exposure using an International Organization for Standardization (ISO) puff regimen. Our findings reveal sex-specific differences in the baseline characteristics of airway epithelial cells. Female mTECs demonstrated stronger barrier function and higher ciliary function compared with males. The barrier function was disrupted in both males and females following chronic CS, but the difference was more significant in females due to their higher baseline. Female mice exhibited transcriptional signatures suggesting dedifferentiation with increased basal cells and markers of cellular senescence. Pathway analysis indicated potential protective roles of planar cell polarity (PCP) in preventing dedifferentiation in male mice exposed to CS. We also observed sex-specific differences in the DNA damage response and antioxidant levels, suggesting distinct mechanisms underlying cellular stress. Understanding these sex-specific mechanisms could facilitate the development of targeted therapeutic strategies for lung diseases associated with environmental insults. Recognizing sex-based differences in disease susceptibility and treatment response can lead to personalized care and improved outcomes. Clinical trials should consider sex as a biological variable to develop effective interventions that address the unique differences between men and women in respiratory diseases.NEW & NOTEWORTHY The study underscores the importance of considering sex-specific differences in the airway epithelium in respiratory diseases such as COPD. Differences in gene expression between males and females at baseline and in response to chronic injury in the airway epithelium could have implications on disease susceptibility, both in COPD and other respiratory diseases. Therefore, understanding these differences is crucial for developing targeted therapies to treat respiratory diseases based on a sex-specific manner.

A Rare Case of 45,X/46,X,del(Y)(q12→qter) Mosaicism in An Infertile Male with Y Chromosome Microdeletion

Background

Males with 45,X/46,XY karyotype have two different types of cells. This condition is associated with a wide range of clinical phenotypes. In infertile males, the mosaic 45,X/46,XY karyotype is a frequent sex chromosome defect and they might be able to conceive with the help of assisted reproductive technology; nevertheless, there is a potential risk of transmission of azoospermia factor (AZF) microdeletions in addition to 45,X to all the male progeny. In this case report, the purpose was to present a rare sex chromosomal mosaicism of an infertile man.

Case Presentation

Comprehensive molecular and cytogenetic analysis of an infertile male was performed in this case study. A 27-year-old male was presented with history of azoospermia and was unable to conceive after being involved in five years of marriage. Cytogenetic investigation revealed a rare mosaic karyotype pattern of 45,X/46,X,del(Y)(q12→qter). Y chromosome microdeletion (YMD) analysis revealed notable deletions of 06 loci. Comparative genomic hybridization (CGH) microarray was performed to investigate probable functional genetic associations.

Conclusion

Deletion of Y-linked genes leads to different testicular pathological conditions contributing to male infertility. Individuals with normal male phenotype harbor YMD, although size and location of the deletion do not always correspond well with quality of sperm. Therefore, in addition to semen analysis, identification of genetic variables is important which will play a crucial role in proper diagnosis and management of infertile couples. The present case study demonstrates the significance of comprehensive molecular testing and cytogenetic screening for individuals with idiopathic infertility.

Benchmarking of human Y-chromosomal haplogroup classifiers with whole-genome and whole-exome sequence data

In anthropological, medical, and forensic studies, the nonrecombinant region of the human Y chromosome (NRY) enables accurate reconstruction of pedigree relationships and retrieval of ancestral information. Using high-throughput sequencing (HTS) data, we present a benchmarking analysis of command-line tools for NRY haplogroup classification. The evaluation was performed using paired Illumina data from whole-genome sequencing (WGS) and whole-exome sequencing (WES) experiments from 50 unrelated donors. Additionally, as a validation, we also used paired WGS/WES datasets of 54 individuals from the 1000 Genomes Project. Finally, we evaluated the tools on data from third-generation HTS obtained from a subset of donors and one reference sample. Our results show that WES, despite typically offering less genealogical resolution than WGS, is an effective method for determining the NRY haplogroup. Y-LineageTracker and Yleaf showed the highest accuracy for WGS data, classifying precisely 98% and 96% of the samples, respectively. Yleaf outperforms all benchmarked tools in the WES data, classifying approximately 90% of the samples. Yleaf, Y-LineageTracker, and pathPhynder can correctly classify most samples (88%) sequenced with third-generation HTS. As a result, Yleaf provides the best performance for applications that use WGS and WES. Overall, our study offers researchers with a guide that allows them to select the most appropriate tool to analyze the NRY region using both second- and third-generation HTS data.

Male infertility

Clinical infertility is the inability of a couple to conceive after 12 months of trying. Male factors are estimated to contribute to 30-50% of cases of infertility. Infertility or reduced fertility can result from testicular dysfunction, endocrinopathies, lifestyle factors (such as tobacco and obesity), congenital anatomical factors, gonadotoxic exposures and ageing, among others. The evaluation of male infertility includes detailed history taking, focused physical examination and selective laboratory testing, including semen analysis. Treatments include lifestyle optimization, empirical or targeted medical therapy as well as surgical therapies that lead to measurable improvement in fertility. Although male infertility is recognized as a disease with effects on quality of life for both members of the infertile couple, fewer data exist on specific quantification and impact compared with other health-related conditions.

Molecular and cytogenetic analysis of small supernumerary marker chromosomes in prenatal diagnosis

BACKGROUND

Small supernumerary marker chromosome (sSMC) is a structurally abnormal chromosome of unknown origin by conventional cytogenetics. The understanding of clinical significance of sSMC is still limited in prenatal diagnosis. The presence of sSMC poses a challenge for genetic counselling.

METHODS

We obtained the clinical information of 25 cases with sSMC. The fetal samples were subjected to multiple molecular and cytogenetic approaches including karyotype analysis, chromosomal microarray analysis, bacterial artificial chromosomes-on-beads assay, and fluorescence in situ hybridization.

RESULTS

Seven sSMCs were found to be r(X), and five of the cases terminated the pregnancy. Three markers were idic(15), and one of the cases was normal at birth. Two markers were i(12p), and both cases terminated the pregnancy. Other markers were r(Y) (outcome: normal at birth), i(18p) (outcome: stillbirth), der(15) (outcome: terminated), del(9) (outcome: terminated), dup(13) (outcome: follow-up loss), and derived from chromosome 21 (outcome: stillbirth). Seven markers were of unknown origin because not all methods were applied to them.

CONCLUSION

Applying multiple molecular and cytogenetic approaches could identify the origin and genetic content of sSMC to assist the genetic counselling in prenatal diagnosis.

Mosaic loss of the Y chromosome in human neurodegenerative and oncological diseases

The development of new biomarkers for prediction and early detection of human diseases, as well as for monitoring the response to therapy is one of the most relevant areas of modern human genetics and genomics. Until recently, it was believed that the function of human Y chromosome genes was limited to determining sex and controlling spermatogenesis. Thanks to occurance of large databases of the genome-wide association study (GWAS), there has been a transition to the use of large samples for analyzing genetic changes in both normal and pathological conditions. This has made it possible to assess the association of mosaic aneuploidy of the Y chromosome in somatic cells with a shorter lifespan in men compared to women. Based on data from the UK Biobank, an association was found between mosaic loss of the Y chromosome (mLOY) in peripheral blood leukocytes and the age of men over 70, as well as a number of oncological, cardiac, metabolic, neurodegenerative, and psychiatric diseases. As a result, mLOY in peripheral blood cells has been considered a potential marker of biological age in men and as a marker of certain age-related diseases. Currently, numerous associations have been identified between mLOY and genes based on GWAS and transcriptomes in affected tissues. However, the exact cause of mLOY and the impact and consequences of this phenomenon at the whole organism level have not been established. In particular, it is unclear whether aneuploidy of the Y chromosome in blood cells may affect the development of pathologies that manifest in other organs, such as the brain in Alzheimer's disease, or whether it is a neutral biomarker of general genomic instability. This review examines the main pathologies and genetic factors associated with mLOY, as well as the hypotheses regarding their interplay. Special attention is given to recent studies on mLOY in brain cells in Alzheimer's disease.

Screening Y Chromosome Microdeletion in 1121 Men with Low Sperm Concentration and the Outcomes of Microdissection Testicular Sperm Extraction (mTESE) for Sperm Retrieval from Azoospermic Patients

Background

The Y chromosome has a specific region, namely the Azoospermia Factor (AZF) because azoospermia is typically reported in the microdeletion of the AZF region. This study aims to assess the characteristics of AZF microdeletion after screening a massive number of low sperm concentration men; and the Microdissection testicular sperm extraction (mTESE) outcomes for retrieving sperm from azoospermic patients.

Materials and Methods

This retrospective multiple-center study enrolled a total of 1121 men with azoospermia, cryptozoospermia, and severe oligozoospermia from December 2016 to June 2022. An extension analysis used a total of 17 STSs to detect the position-occurring microdeletion in the AZF region (AZFa, b, c, and/or d loci). Microdissection testicular sperm extraction (mTESE) was performed to retrieve sperm in azoospermic men diagnosed AZFc microdeletion.

Results

One hundred and fifty-three men carried AZF microdeletion were detected in the 1121 participants (13.64%). The incidences of AZF microdeletion were confined to AZF a, c, and d regions, both individual and concurrence, with the most common in the AZFc region accounting for 49.67%; There was no significant difference in clinical and paraclinical characteristics between the deleted regions, except FSH level (highest in AZFa microdeletion, p = 0.043). The AZFc region was the most common type of AZF microdeletion (49.67%), including complete microdeletion (4 patients) and gr/gr partial microdeletion (39 patients) with 50.00% and 63.63% in the success rate of mTESE, separately.

Conclusion

The absence of AZFa and/or AZFb regions often express the most severe phenotype - azoospermia and the increasing FSH level. The AZFc region played the most common microdeletion. Microdissection testicular sperm extraction (mTESE) was the possible therapy for sperm retrieval from the testis of azoospermia men having AZFc microdeletion.