Genetic risk factors in infertile men with severe oligozoospermia and azoospermia

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.

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

STUDY QUESTION

Does Klinefelter syndrome (KS) lead to a distinct gene expression pattern at single-cell level in the testes that could provide insight into the reported microvascular dysfunction in the testes?

SUMMARY ANSWER

A distinct gene expression pattern within microvascular-associated cells of males with KS suggests excessive endothelial cell (EC) activation, disorganized vessel formation, and the presence of immature vessels with compromised integrity.

WHAT IS KNOWN ALREADY

Recent studies show that males with KS exhibit microvascular dysfunction in their testes, which affects blood flow and is associated with lower circulating levels of testosterone.

STUDY DESIGN, SIZE, DURATION

A comparative cross-sectional study of males with KS (n = 6), non-obstructive azoospermia (NOA) (n = 5), cryptozoospermia (n = 3), and controls (n = 15) was carried out.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We analyzed publicly available single-cell RNA sequencing data of testicular cells from males with KS, males with NOA, males with cryptozoospermia, and controls. The integration of these datasets allowed us to analyze gene expression profiles and communication patterns among the cell types within the testis and to identify capillary ECs to investigate changes at the microvascular level.

MAIN RESULTS AND THE ROLE OF CHANCE

Rooted in changes at the single-cell level, our study demonstrates a shift in gene expression forming the foundation for altered cellular communication, microvascular remodeling, and pro-inflammatory responses within the testes of males with KS. We identified genes that were dysregulated in capillary ECs from males with KS (Padj < 0.05). Specifically, the unique microvascular gene expression in males with KS indicated enhanced capillary EC activation and increased inflammatory cross-talk, leading to impaired vessel maturation and increased EC barrier permeability.

LIMITATIONS, REASONS FOR CAUTION

Our study is constrained by an unbalanced design, with varying sample sizes and number of cells within each group. We acknowledge the restricted access to clinical information. In addition, our findings were deduced from changes in gene expression, which limits us to infer potential biological consequences arising from these alterations. Furthermore, the absence of a pre-pubertal age group limits the generalizability of our findings and warrants further investigation.

WIDER IMPLICATIONS OF THE FINDINGS

This study offers novel insights into the testicular pathophysiology in KS and underscores the potential contribution of microvascular dysfunction to the hypogonadism and infertility observed in males with KS. While this study aims to better understand the microvascular dysfunction in KS, the precise connections to testosterone deficiency and testicular atrophy remain to be fully elucidated.

STUDY FUNDING/COMPETING INTEREST(S)

A.S. was supported by the Independent Research Fund Denmark (0134-00130B). C.H.G. was supported by Novo Nordisk Foundation (NNF15OC0016474, NNF20OC0060610), 'Fonden til lægevidenskabens fremme', the Familien Hede Nielsen foundation and the Independent Research Fund Denmark (0134-00406A). E.B.J. was supported by Aarhus University and E.B.J. and C.H.G by the Independent Research Fund Denmark (2096-00165A). J.M.K. was supported by Lundbeckfonden (R307-2018-3667), Carlsberg Fonden (CF19-0687), Novo Nordisk Fonden (0073440) and Steno Diabetes Center Aarhus (SDCA). The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

The '-ics' of male reproduction: genomics, epigenetics, proteomics, metabolomics, and microbiomics

PURPOSE OF REVIEW

To review the most current findings, from the past 2 years, in various '-ics' fields in male infertility, with a specific focus on nonobstructive azoospermia, the most severe form, and varicocele, the most common correctable cause of male infertility.

RECENT FINDINGS

Recent studies confirm previously identified causes and identify previously unknown genetic mutations as causes for nonobstructive azoospermia and varicocele.

SUMMARY

Infertility is a common problem for couples with approximately half of cases attributable to male factor infertility. Although advances in assisted reproductive technology have permitted many more men with infertility to father biological children, the majority of infertile men continue to have unknown causes. The recent explosion of the '-ics' fields, including genomics, epigenetics, proteomics, metabolomics, and microbiomics, has shed light on previously unknown causes for various diseases. New information in these fields will not only shed light on the pathogenesis of these conditions but also may shift the paradigm in clinical testing that may allow clinicians to provide more precise counseling and prognostic information for men with infertility.

Screening by single-molecule molecular inversion probes targeted sequencing panel of candidate genes of infertility in azoospermic infertile Jordanian males

Infertility is a common health problem that affects around 1 in 6 couples in the United States, where half of these cases are attributed to male factors. Genetics play an important role in infertility and it is estimated that up to 50% of cases are due to genetic factors. Despite this, many male infertility cases are still idiopathic. This study aimed to identify the presence of possibly pathogenic rare variants in a set of candidate genes related to azoospermia in 69 Jordanian men using a next-generation sequencing-based panel covering more than a hundred male infertility related genes. A total of 9 variants were found and validated. Among them, two variants included reported pathogenic variants in CFTR and one novel pathogenic variant in the USP9Y gene. We also report the detection of 6 other variants with uncertain significance in other genes. Interestingly, male cases with CFTR variants did not show the expected cystic fibrosis phenotypes except for infertility. This work helps to uncover the contribution of additional genetic factors to the aetiology of male infertility and highlights the importance to obtain more reliable information about the presence of genetic variation in the Jordanian population.

Sperm selection with Annexin-V coated polystrene bead technique (APB-Tech): A novel and reliable method for the microscopic selection of viable and non-apoptotic sperm to be used for intracytoplasmic sperm injection

Infertility is a growing health problem that affects 20% of couples who want to conceive. 'Intracytoplasmic sperm injection' (ICSI) is a commonly used assisted reproduction treatment technique that offers the couples to overcome a wide variety of infertility reasons, including female, male and unexplained infertility. A crucial step in ICSI is choosing the correct sperm with the highest potential to form a healthy embryo and thus a healthy offspring. The sperm selection strategies aim to obtain a sperm population with better motility and morphology, which are insufficient to predict a sperm's reproductive potential. The elimination of apoptotic sperms, which is shown to be higher in infertile males and which is shown to affect embryo development and reproductive cohort significantly should also be included in the selection strategies. Among all sperm selection methods, there are only a few which can eliminate apoptotic sperm, but because they need extra types of equipments, a long training period, and high costs, they couldn't find place in the most commonly used techniques in an IVF lab. Selecting the non-apoptotic sperm cells will help us choose a sperm that is more likely to be chosen by the natural selection mechanisms and thus will help to mimic the natural conception more. The study aimed to develop a novel, easy and a harmless individual sperm selection technique to enable choosing non-apoptotic viable sperm cells via light microscopy without any need for extra equipment, education and cost to be used for ''ICSI'. The technique is based on the binding ability of Annexin-V covered polystrene beads to the externalized phosphatidylserine at the outer leaflet of an apoptotic sperm's plasma membrane. After Annexin-V covered polystyrene beads were prepared, beads obtained were attached to BALB-c mice sperm, and the technique is optimized to obtain the most efficient attachment conditions. The results are then compared with the results of four well-known reliable apoptosis detection techniques to test the validity and sperm survival test to test the toxicity of the technique. The method is proven to be '''reliable' by comparing it with the results of well-known techniques, including TUNEL and SCSA (sperm chromatin structure assay), and '''safe' by showing its non-toxicity via sperm survival test (SST). In addition, the method enables the selection of sperm cells more closer to naturally-chosen ones from a pool of sperm that should not be allowed to be randomly chosen during microinjection. To date, it was impossible to distinguish a non-apoptotic sperm without harming it or without needing additional equipment other than a routine IVF lab and extra training other than routine andrology work. The technique is named as 'Annexin-V coated polystyrene bead technique (APB-Tech)'. Based on our results, further studies on APB-Tech should be focused on the possible improvement of ICSI outcomes and, thus, success rates.

Effects of Chromosomal Translocations on Sperm Count in Azoospermic and Oligospermic Cases

Purpose A number of mechanisms have been proposed for the effect of chromosomal translocations on spermatogenesis and sperm maturation. However, there are still numerous ambiguous issues regarding these two processes. The aim of this study is to evaluate the effect of chromosome break areas on sperm count in the light of the literature. Material and Methods The study was conducted on the data of 16 male patients with reciprocal or Robertsonian translocation among 152 patients who were admitted to Adana Numune Training and Research Hospital and Kanuni Sultan Süleyman Training and Research Hospital Genetic Diagnosis Centers between 2013 and 2016 due to azoospermia and oligospermia. Results 11 of these patients had reciprocal and five patients had Robertsonian translocations. All the patients with Robertsonian translocations were detected with azoospermia. Of the patients with reciprocal translocation, five of them were azoospermic and six of them were severe oligospermic. Conclusion A total of 21 chromosomal breakpoints were identified in the 11 patients with reciprocal translocations. These chromosomal breakpoints may contribute to the clarification of ambiguous issues related to spermatogenesis and sperm maturation. The results also showed the importance of genetic counselling in patients with translocations.

A rare frameshift mutation in SYCP1 is associated with human male infertility

Proper assembly of the synaptonemal complex is essential for successful meiosis, and impairments in the process lead to infertility. Meiotic transverse filament proteins encoded by the SYCP1 (synaptonemal complex protein 1) gene are one of the main components of the synaptonemal complex and play an important role in correct synapsis and recombination. Family-based whole exome sequencing revealed a rare homozygous SYCP1 frameshift mutation (c.2892delA: p.K967Nfs*1) in two men with severe oligozoospermia, followed by validation and segregation through Sanger sequencing. This single nucleotide deletion not only changes lysine 967 (K) into asparagine (N) but also causes a premature stop codon, which leads to deletion of 968-976 residues from the end of the C-tail region of the SYCP1 protein. Although, sycp1 knockout male mice are reported to be sterile with a complete lack of spermatids and spermatozoa, to date no SYCP1 variant has been associated with human oligozoospermia. HADDOCK analysis indicated that this mutation decreases the ability of the truncated SYCP1 protein to bind DNA. Immunodetection of ϒH2AX signal, in SYCP1 mutant semen cells and a 40% DNA fragmentation index might indicate that a small number of DNA double-strand breaks, which require SYCP1 and/or synapsis to be repaired, are not efficiently repaired, resulting in defects in differentiation of germline cells and appearance of the oligozoospermia phenotype. To our knowledge, this is the first report of homozygous SYCP1 mutation that decreases sperm count. Further studies are required to determine the function of the SYCP1 mutation, which is potentially associated with human oligozoospermia.

Association of Novel Single Nucleotide Polymorphisms of Genes Involved in Cell Functions with Male Infertility: A Study of Male Cases in Northwest Iran

Background

Infertility is a global health problem caused by various environmental and genetic factors. Male infertility accounts for 40-50% of all cases of infertility and approximately half of them are grouped as idiopathic with no definitive causes. Previous studies have suggested an association between some SNPs and infertility in men. In this study, an attempt was made to investigate the association of 7 different SNPs of 4 genes involved in common cell functions with male infertility.

Methods

MTHFR rs1801131 (T>G), MTHFR rs2274976 (G>A), FASLG rs80358238 (A>G), FASLG rs12079514 (A>C), GSTM1 rs1192077068 (G>A), BRCA2 rs4987117 (C>T), and BRCA2 rs11571833 (A>T) were genotyped in 120 infertile men with idiopathic azoospermia or severe oligospermia and 120 proven fertile controls using ARMS-PCR methods. Next, 30% of SNPs were regenotyped to confirm the results. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using SPSS statistical software to evaluate the strength of association. The p<0.05 were considered statistically significant.

Results

Statistical analysis revealed significant association between MTHFR rs-2274976 AA variant (OR: 10.00, CI: 3.203-31.225), FASLG rs12079514 AC variant (OR: 0.412, CI: 0.212-0.800), and BRCA2 rs11571833 TT variant OR: 6.233, CI: 3.211-12.101) with male infertility, but there was no significant difference between case and control groups in MTHFR rs1801131 (p= 0.111), GSTM1 rs1192077068 (p=0.272), BRCA2 rs4987117 (p=0.221), and FASLG rs80358238 (p=0.161).

Conclusion

Our findings suggested that some novel polymorphisms including MTHFR rs2274976, FASLG rs12079514, and BRCA2 rs11571833 might be the possible predisposing risk factors for male infertility in cases with idiopathic azoospermia.

Clinical Outcomes and Live Birth Rate Resulted From Microdissection Testicular Sperm Extraction With ICSI-IVF in Non-Obstructive Azoospermia: A Single-Center Cohort Study

BACKGROUND

Most of data available in the literature reported the sperm retrieval rate and limited intracytoplasmic sperm injection (ICSI) results of microdissection testicular sperm extraction (micro-TESE) in non-obstructive azoospermia (NOA) patients with different etiologies. Unfortunately, there is currently a lack of comprehensive data to guide clinicians in conducting comprehensive consultations with NOA patients.

OBJECTIVES

To obtain more comprehensive evidence-based data and clinical outcomes for better consultation of NOA patients who opted to undergo micro-TESE combined with ICSI-IVF.

METHODS

It was a retrospective study involved 968 NOA patients underwent micro-TESE during January 2015 to December 2019. Embryological, clinical, and live birth outcomes were demonstrated comprehensively and three kinds of stratification analyses were performed based on ICSI-IVF cycles using frozen and fresh sperm, different etiologies of NOA and various amounts of sperm retrieved.

RESULTS

The sperm retrieval rate was 44.6%, and ICSI was performed in 299 couples leading to 150 clinical pregnancies and 140 live-birth deliveries. The clinical pregnancy rate (CPR) was 50.17%, and the cumulative live birth rate (LBR) was 46.82%, and the low birth defects rate was 1.43%. No significant difference was observed about cumulative LBR in frozen sperm group and fresh sperm group (47.5% vs 42.9%, P>0.05). NOA patients with AZFc microdeletions had the lowest rate of a high-score embryo on day 3 (4.4%, P<0.05) and the lowest cumulative LBR (19.4%, P<0.05). NOA patients with lower sperm count (having fewer than 20 sperms retrieved) had significantly lower cumulative LBR than those with higher sperm count (having more than 20 sperms retrieved) (28.1% vs 51.9%, P<0.05).

CONCLUSIONS

For those NOA patients who stepped in ICSI-IVF cycles, the cumulative LBR was 46.82%. No significant difference was indicated in the LBR between ICSI-IVF cycles using frozen or fresh testicular sperm. Compared to other etiologies, NOA caused by AZFc microdeletions have the poorest embryological and clinical outcomes. Patients with less testicular sperm retrieved have poorer embryological and clinical outcomes.

Different group of non-obstructive intermittent azoospermias among non-obstructive azoospermia patients: A ten-year retrospective cohort study with control group

We have identified patients among non-obstructive azoospermia (NOA) cases in whom spermatozoa could not be detected despite treatment, but intermittent ejaculatory spermatozoon was found in their follow-up. NOA was observed in the retrospective screening at a rate of 15.35% among infertile men (n = 1976/12,871), while non-obstructive intermittent azoospermia (NO-IA) was detected at a rate of 6.8% among NO-IA (n = 135/1976) and 1.1% among all infertile men (n = 135/12,871). Spermatozoon was identified in the form of cryptospermia or extreme oligospermia in 58.13 (13.6-92.3) weeks on average in n = 55/135 patients among NO-IA. Pregnancy and live birth were achieved at a rate of 43.6% (n = 24/55) and 29% (n = 16/55), respectively, in intracytoplasmic sperm injection. NO-IA was composed of a group with no genetic pathological diagnosis, with lower follicle-stimulating hormone, lutenizing hormone and clinical varicocele rates compared with those of NOA (<0.05) and higher testicular volumes and pathological scores (<0.05). A major activity was observed in total testosterone, lutenizing hormone, testicular volumes and the logistic regression of pathological scores (<0.05).

Association between intake of soft drinks and testicular function in young men

STUDY QUESTION

Is intake of sugar-sweetened beverages (SSB) or artificially sweetened beverages (ASB) associated with testicular function in young men?

SUMMARY ANSWER

Among young men unaware of their semen quality and reproductive hormone levels, intake of SSBs was associated with lower sperm concentration, lower total sperm count, and a lower ratio of serum inhibin-B/FSH.

WHAT IS KNOWN ALREADY

SSBs may adversely impact testicular function, but results are not consistent across studies. Moreover, the associations of ASB, energy-drinks or fruit juices with testicular function are unclear.

STUDY DESIGN, SIZE, DURATION

Young healthy men and unselected for fertility status men enrolled in a cross-sectional study between 2008 and 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 2935 young (median age: 19 years) men enrolled in the study. Intake of SSBs, ASBs, fruit juices, and energy-drinks was assessed with a validated food frequency questionnaire. Testicular function was assessed through conventional semen quality parameters (semen volume, sperm concentration, total count, motility and morphology), testicular volume assessed with ultrasound, and serum reproductive hormone concentrations (total testosterone, free testosterone, E2, inhibin-B, LH, FSH, sex hormone-binding globulin) were measured.

MAIN RESULTS AND THE ROLE OF CHANCE

In multivariable-adjusted analyses, men in the highest category of SSB intake (median: 1.1 servings (∼220 ml)/day) had a 13.2 million/ml lower median sperm concentration (95% CI: -21.0, -5.5) than non-consumers. A similar pattern was observed with total sperm count (-28 million (95% CI: -48, -9)), serum inhibin-B (-12 pg/ml (95% CI: -21, -4)), and inhibin-B/FSH ratio (-9 (95% CI: -18, 0)). The adjusted median difference in sperm concentration and inhibin-B associated with increasing SSB intake by 1 serving (∼200ml)/day at the expense of water was -3.4 million sperm/ml (95% CI: -5.8, -1.0) and -7 pg/ml (95% CI: -11, -3), respectively.

LIMITATIONS, REASONS FOR CAUTION

Inferring causality is limited owing to the cross-sectional design. We adjusted for a number of potential confounders but cannot exclude that unmeasured lifestyle and behavior associated with soft drink intake is associated with testicular function in these young men.

WIDER IMPLICATIONS OF THE FINDINGS

In the largest study to date, intake of SSBs was associated with lower sperm concentration, total sperm count, and serum inhibin-B/FSH ratio, consistent with a direct suppressive effect of SSB intake on testicular function among otherwise healthy men, potentially affecting fertility. However, the observed association between higher SSB intake and lower semen quality does not necessarily imply a decrease in fertility.

STUDY FUNDING/COMPETING INTEREST(S)

Supported by research from the Danish Council for Strategic Research (2101-08-0058), Independent Research Fund Denmark (8020-00218B), European Union (212844), the Kirsten and Freddy Johansen's Foundation (95-103-72087), the Research Fund of the Capital Region of Denmark (A6176), and the NIH (P30DK046200). The authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Canary in the Coal Mine? Male Infertility as a Marker of Overall Health

Male factor infertility is a common problem. Evidence is emerging regarding the spectrum of systemic disease and illness harbored by infertile men who otherwise appear healthy. In this review, we present evidence that infertile men have poor overall health and increased morbidity and mortality, increased rates of both genitourinary and non-genitourinary malignancy, and greater risks of systemic disease. The review also highlights numerous genetic conditions associated with male infertility as well as emerging translational evidence of genitourinary birth defects and their impact on male infertility. Finally, parallels to the overall health of infertile women are presented. This review highlights the importance of a comprehensive health evaluation of men who present for an infertility assessment.

Evaluation of association between methylenetetrahydrofolate reductase and azoospermia: A meta-analysis

BACKGROUND

Infertility affects childbearing age couples all over the world. One of the important reasons for infertility is genetic factors. Our study evaluated the association between methylenetetrahydrofolate reductase (MTHFR) and azoospermia.

METHODS

Multiple databases like MEDLINE, EMBASE, Cochrane library, and China journal full-text database were used to search for relevant studies, and full-text articles involved in the evaluation of MTHFR and azoospermia. The results were evaluated using STATA 12.0. Heterogeneity analysis, sensitivity analysis, and bias analysis were also performed on the data.

RESULTS

Thirteen related studies eventually met the inclusion criteria. Significant association between C677T polymorphism and azoospermia (relative risk [RR] = 0.94 [0.90, 0.99], I2 = 60.9%, P = .002), and between A1298C polymorphism and azoospermia (RR = 0.98 [0.94, 1.02], I2 = 56.3%, P = .011) was observed. Meanwhile, in subgroup analysis, Caucasians had higher risk than Mongolians in association between MTHFR and azoospermia.

CONCLUSION

There was association between MTHFR polymorphism and azoospermia. Caucasian populations had higher risk than Mongolian populations in association between MTHFR and azoospermia.

Photobiomodulation Therapy Improves Spermatogenesis in Busulfan-Induced Infertile Mouse

About 50% of infertility is caused by men. This study aimed to investigate the efficiency of photobiomodulation on spermatogenesis in a busulfan-induced infertile mouse as a testicular degeneration treatment. Thirty-two adult NMRI male mice were divided into 4 groups: control, busulfan, PBMT 0.03 J/cm², and laser 0.2 J/cm². In the study, azoospermia was induced by busulfan as a testicular degeneration, and then, they were treated using photobiomodulation therapy at 0.03 J/cm2 and 0.2 J/cm² energy densities. Sperm parameters, stereological analysis, serum testosterone levels, together with SDH activity, MDA production oxidized as a marker for lipid peroxidation, glutathione (GSSG) and glutathione (GSH), mitochondrial membrane permeability (MMP), reactive oxygen species (ROS) production, and ATP production as well as TUNEL assay were assessed. Photobiomodulation therapy with 0.03 J/cm² energy densities group revealed a significant increase the testosterone hormone level and spermatogenic cells with the reduction of apoptotic cells and marked increase in GSH, ATP, and SDH levels and decrease the levels of MDA and ROS production in the busulfan-induced mice when compared with the control and sham groups. In conclusion, the photobiomodulation therapy (0.03 J/cm² energy density) may provide benefits on the spermatogenesis following busulfan injection and might be an alternative treatment to the patients with oligospermia and azoospermia in a dose-dependent manner.

Genetic counseling prior to assisted reproductive technology

BACKGROUND

Reproductive medicine deals with fertility and is closely related to heredity. In reproductive medicine, it is necessary to provide genetic information for the patients prior to assisted reproductive technology (ART). Japan Society for Reproductive Medicine (JSRM) requires doctors involved in reproductive medicine to have standard knowledge of reproductive genetics and knowledge of reproductive medicine, which is covered in their publication, "required knowledge of reproductive medicine."

METHODS

With the aim of providing straightforward explanations to patients in the clinical situation at pre-ART counseling, we provide the following five topics, such as (a) risk of birth defects in children born with ART, (b) chromosomal abnormalities, (c) Y chromosome microdeletions (YCMs), (d) possible chromosomal abnormal pregnancy in oligospermatozoa requiring ICSI (intracytoplasmic sperm injection), and (e) epigenetic alterations.

MAIN FINDINGS

The frequency of chromosome abnormalities in infertile patients is 0.595%-0.64%. YCMs are observed in 2%-10% of severe oligospermic men. High incidence of spermatozoa with chromosomal abnormalities has been reported in advanced oligospermia and asthenozoospermia that require ICSI. Some epigenetic alterations were reported in the children born with ART.

CONCLUSION

Certain genetic knowledge is important for professionals involved in reproductive medicine, even if they are not genetic experts.

Evaluation of Y chromosome microdeletions and chromosomal anomalies in infertile men

OBJECTIVES

Chromosome anomalies and Y chromosome microdeletions are one of the reasons that can be seen in infertile patients and affect fertility. In this study, it was aimed to determine the frequencies of chromosomal anomalies and Y chromosome microdeletions in primary infertile male patients.

METHODS

We included 374 patients with primary infertility in this study. Cytogenetic analysis was performed with the GTG banding technique by using trypsin and Giemsa stain. Y microdeletion analysis was studied by multiplex polymerase chain reaction using 28 Y chromosome-specific sequence-tagged sites.

RESULTS

Chromosomal irregularities were detected in 27 (7.22%) of infertile cases. It was observed that 7 (25.92%) of chromosomal irregularities detected in cases were in autosomal and 20 (%74.08) were in gonosomal chromosomes. The incidence of Y chromosome microdeletion was 1.07% (4/374) and the microdeletions were observed in AZFb, AZFc and AZFd regions. AZFc + AZFd deletion was detected in three patients (0.81%) and AZFb + AZFc + AZFd deletion in one patient (0.26%).

CONCLUSIONS

In conclusion, gonosomal chromosome irregularity was higher than autosomal chromosome irregularity in infertile men. The frequency of Y microdeletion has different rates according to some factors such as ethnic differences of patients, patient selection criteria, differences in the number of cases, and methodological aspects.

Lower total motile count is associated with smaller historic intergenerational family size: a pedigree analysis from the Utah Population Database

PURPOSE

To describe the association between contemporary total motile count (TMC), a measure of male factor infertility, and historic intergenerational family size.

METHODS

This is a retrospective, population-based, cohort study of men who underwent semen analysis for infertility workup at University of Utah, with at least a single measure of TMC, who were linked to extensive genealogical data. Two thousand one hundred eighty-two pedigree branches of men with a measure of TMC within the UPDB were identified. We identified the average number of generations and offspring within each generation. Conditional logistic regression models were used to assess the association between the risk of having a TMC in the 5th or 25th percentile and intergenerational family size. Generalized estimating equations (GEE) were used to assess the association between interval-level TMC and the number of ancestral offspring.

RESULTS

We found no association between intergenerational size and TMC within the 5th percentile (TMC < 4 million; RR = 0.97, 95% CI 0.93-1.01) or the 25th percentile (TMC < 62 million; RR = 1.00, 95% CI 0.97-1.03). When TMC was analyzed as a continuous variable, we found that lower TMC is associated with smaller intergenerational family size. For every additional child in their ancestral pedigree, we observed an increase in TMC of 1.88 million (p = 0.03). Men in the top quartile for intergenerational family size had a TMC that was 48 million higher than men in the bottom quartile (p = 0.047).

CONCLUSIONS

We found an association between TMC and ancestral family size, suggesting that lower TMC is associated with smaller intergenerational family size.

Effect of Y Chromosome Microdeletions on the Pregnancy Outcome of Assisted Reproduction Technology: a Meta-analysis

This systematic analysis aimed to summarize the effects of Y chromosome microdeletions (YCMs) on pregnancy outcomes of assisted reproductive technology (ART). This retrospective controlled meta-analysis evaluated the effect of YCMs on pregnancy outcomes of ART. Full-text retrieval was conducted in the PubMed, CBM, Web of Science, CNKI, VIP, and WANFANG databases. The pregnancy outcomes included fertilization rate, good embryo rate, clinical pregnancy rate, early miscarriage rate, miscarriage rate, live birth rate, and baby boy rate. The quality of these studies was evaluated using the Newcastle-Ottawa scale. Statistical software Review Manager 5.3 and STATA 14.0 were used. Twelve high-quality studies were included in the analysis. Compared with that in the normal group, the fertilization rate in the YCMs group decreased significantly (odds ratio [OR] = 0.75, 95% confidence interval [CI] [0.63, 0.88], P = 0.0006). However, there was no significant difference (P > 0.05) between groups in the good embryo rate (OR = 0.88, 95% CI [0.72, 1.07]), clinical pregnancy rate (OR = 0.94, 95% CI [0.78, 1.11]), early miscarriage rate (OR = 1.70, 95% CI [0.93, 3.10]), miscarriage rate (OR = 1.3, 95% CI [0.93, 1.91]), live birth rate (OR = 0.90, 95% CI [0.74, 1.08]), and baby boy rate (OR = 1.15, 95% CI [0.85, 1.56]). YCMs are associated with a reduced fertilization rate of ART, but they do not decrease the good embryo rate, clinical pregnancy rate, early miscarriage rate, miscarriage rate, live birth rate, or baby boy rate.

Nonsurgical Management of Oligozoospermia

Male infertility secondary to oligozoospermia is surprisingly common. Although a majority of cases are idiopathic, oligozoospermia can be caused by endocrine dysfunction, anatomic abnormalities, medications, or environmental exposures. The work-up includes excluding reversible factors such as hormonal deficiency, medication effects, and retrograde ejaculation and identifying any underlying genetic syndrome and treating reversible medical causes. If no reversible cause is found, appropriate referrals to urology and assisted reproductive technology should be initiated. Lastly, clinicians should be aware of and respond to the psychological and general health ramifications of a diagnosis of oligozoospermia as part of the comprehensive care of men and couples struggling with a diagnosis of infertility.

Cytogenetic and molecular study of 370 infertile men in South India highlighting the importance of copy number variations by multiplex ligation-dependent probe amplification

Male infertility is a common and severe problem affecting 7% of population. The main objective of this study is to identify the chromosomal abnormalities, Y microdeletions in infertile men and also to access the frequency of abnormal sperm count. Based on the sperm count and viability, the infertile men were grouped as Azoospermia, Asthenospermia, Oligospermia and the remaining as Idiopathic infertility. A total of 370 infertile men and 60 normal control men were recruited. Chromosomal abnormalities were identified in 3 men (3/370). The prevalence of Y microdeletions in the infertile group is 8/370 in the Azoospermia factor (AZF) region with four AZFc deletion/duplication, two AZFa deletion, one AZF b & AZFc deletion and one case of total AZF a, AZFb & AZFc deletion. However, only five cases of Y microdeletions were identified by Multiplex PCR but an additional three cases by MLPA (Multiplex ligation-dependent probe amplification). Fluorescence in situ hybridisation also confirmed the deletions. Here, we performed MLPA post-multiplex PCR, and our study revealed good yield of the Y microdeletion identification. The partial duplications which are difficult to be identified can now be easily identified by MLPA, and hence, we recommend MLPA as the choice of investigation compared to multiplex PCR for infertile men.

Cystic fibrosis gene mutations and polymorphisms in Saudi men with infertility

BACKGROUND

Some mutations of the cystic fibrosis transmembrane regulator (CFTR) gene may impair spermatogenesis or cause a congenital absence of the vas deferens that manifests as isolated male infertility.

OBJECTIVE

Assess the frequency and analyze the spectrum of CFTR gene variations in Saudi men with primary infertility.

DESIGN

Prospective, cross-sectional.

SETTING

Tertiary care specialist hospital in Jeddah.

PATIENTS AND METHODS

Genomic DNA was extracted from peripheral blood samples of Saudi men who presented with primary infertility to the outpatient andrology clinic with either azoospermia or oligoasthenoteratozoospermia. Polymerase chain reaction and direct sequencing were used to identify all variants of the CFTR gene.

MAIN OUTCOME MEASURES

Proportion of the patients with a mutant CFTR gene and the spectrum of CFTR gene variations.

SAMPLE SIZE

50 infertile Saudi men.

RESULTS

This study identified 10 CFTR gene variants in 7 (14%) subjects (100 chromosomes). The detected variants and polymorphisms were: c.1408G>A, c.4389G>A, c.2562T>G, c.869+11C>T, c.2909-92G>A, c.3469-65C>A, c.1210-6delT, c.1210-6T>A, c.2988+1G>A, and c.1210-13GT>TG.

CONCLUSION

We demonstrated that 14% of the study subjects had one or more CFTR mutations and these were compounded in most of the affected patients. The spectrum of CFTR gene mutations in these subjects was similar to the mutations reported in other studies throughout the world.

LIMITATIONS

Small sample size and the lack of a control group.

CONFLICTS OF INTEREST

None.

A rare karyotype of nonmosaic isodicentric (Y) (p11.31) with azoospermia and short stature

Chromosome aberration is one of the common causes of male infertility. Isodicentric chromosome is a chromosomal aberration in which two arms of a chromosome are identical in morphology and genetics and connected by two centromeres. We firstly reported a case of infertile male with nonmosaic 46, X, idic (Y) (qter-p11.31::p11.31-qter) but with the sex-determining region Y (SRY). The broken site is the chromosome Y (p11.31). The patients' clinical phenotype was azoospermia and short stature. Fluorescence in situ hybridisation (FISH), chromosomal microarray comparative genomic hybridisation (array CGH) and related molecular analysis were performed. Azoospermia of this case may be caused by the abnormal chromosome structure, which leads to abnormal chromosome synapsis in spermatogenesis. Loss of genes in PAR1 and gain of genes copies in azoospermia factor (AZF) region on the Y chromosome may also contribute to the pathogenesis of azoospermia.

Meiotic arrest occurs most frequently at metaphase and is often incomplete in azoospermic men

OBJECTIVE

To establish which meiotic checkpoints are activated in males with severe spermatogenic impairment to improve phenotypic characterization of meiotic defects.

DESIGN

Retrospective observational study.

SETTING

University medical center research laboratory and andrology clinic.

PATIENT(S)

Forty-eight patients with confirmed spermatogenic impairment (Johnsen scores 3-6) and 15 controls (Johnsen score 10).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Quantitative assessment of immunofluorescent analyses of specific markers to determine meiotic entry, chromosome pairing, progression of DNA double-strand break repair, crossover formation, formation of meiotic metaphases, metaphase arrest, and spermatid formation, resulting in a novel classification of human meiotic arrest types.

RESULT(S)

Complete metaphase arrest was observed most frequently (27%), and the patients with the highest frequency of apoptotic metaphases also displayed a reduction in crossover number. Incomplete metaphase arrest was observed in 17% of the patients. Only four patients (8%) displayed a failure to complete meiotic chromosome pairing leading to pachytene arrest. Two new types of meiotic arrest were defined: premetaphase and postmetaphase arrest (15% and 13%, respectively).

CONCLUSION(S)

Meiotic arrest in men occurs most frequently at meiotic metaphase. This arrest can be incomplete, resulting in low numbers of spermatids, and often occurs in association with reduced crossover frequency. The phenotyping approach described here provides mechanistic insights to help identify candidate infertility genes and to assess genotype-phenotype correlations in individual cases.

Epigenetic Inactivation of SOX30 Is Associated with Male Infertility and Offers a Therapy Target for Non-obstructive Azoospermia

Non-obstructive azoospermia (NOA) is the most severe form of male infertility. However, the etiology of NOA is largely unknown, resulting in a lack of clinical treatments. Here, we performed a comparative genome-wide profiling of DNA methylation and identified SOX30 as the most notably hyper-methylated gene at promoter in testicular tissues from NOA patients. This hyper-methylation at promoter of SOX30 directly causes its silencing of expression in NOA. The reduced levels of SOX30 expression are correlated with severity of NOA disease. Deletion of Sox30 in mice uniquely impairs testis development and spermatogenesis with complete absence of spermatozoa in testes leading to male infertility, but does not influence ovary development and female fertility. The pathology and testicular size of Sox30 null mice highly simulate those of NOA patients. Re-expression of Sox30 in Sox30 null mice at adult age reverses the pathological damage of testis and restores the spermatogenesis. The re-presented spermatozoa after re-expression of Sox30 in Sox30 null mice have the ability to start a pregnancy. Moreover, the male offspring of Sox30 re-expression Sox30 null mice still can father children, and these male offspring and their children can live normally more than 1 year without significant difference of physical appearance compared with wild-type mice. In summary, methylated inactivation of SOX30 uniquely impairs spermatogenesis, probably causing NOA disease, and re-expression of SOX30 can successfully restore the spermatogenesis and actual fertility. This study advances our understanding of the pathogenesis of NOA, offering a promising therapy target for NOA disease.

Obstetric and perinatal outcomes of intracytoplasmic sperm injection for infertile men with Y chromosome microdeletions

BACKGROUND

To evaluate the safety of intracytoplasmic sperm injection (ICSI) for men with Y chromosome azoospermia factor (AZF) microdeletions.

METHODS

Twenty-five men with Y chromosome microdeletions and their partners underwent ICSI treatment. These subjects were matched against 50 ICSI cycles in which the patients had normal Y chromosomes.

RESULTS

Among the 25 couples, 17 achieved a clinical pregnancy of which 14 continued to a live birth. Sixteen men had deletions of AZFc markers (sY152, sY254, and sY255), 1 had a deletion of sY152, 3 had a deletion of sY254, sY255, 1 had a deletion of sY152, sY239, Sy242, sY254, and sY255, and 3 had deletions of sY152, sY254, sY255, and sY157. AZFb microdeletions (sY127, sY134, and sY143) were found in 1 patient. AZF microdeletions had no adverse effects on the clinical pregnancy, implantation or delivery rates, birth weight, gestational age, or sex ratio when compared with the control group. Overall, the multiple gestation and preterm delivery rates of the AZF microdeletion group were similar to those in the control group.

CONCLUSION

Men with AZF microdeletions can achieve the delivery of healthy children using ICSI. In this series, it produced good implantation rate and obstetric and perinatal outcomes.

The Prevalence of Y-chromosome Microdeletions in Oligozoospermic Men: A Systematic Review and Meta-analysis of European and North American Studies

CONTEXT

European and North American guidelines recommend Y-chromosome microdeletion (YCM) screening in azoospermic and oligozoospermic men with sperm concentrations of <5 million sperm/ml; however, numerous studies have suggested that YCMs are rare when sperm concentrations are >1 million sperm/ml.

OBJECTIVE

We systematically reviewed and meta-analyzed European and North American studies to determine the prevalence of a complete YCM in oligozoospermic men with sperm concentrations of >0-1, >1-5, and >5-20 million sperm/ml, and to determine whether 1 or 5 million sperm/ml is the most appropriate sperm concentration threshold for YCM screening.

EVIDENCE ACQUISITION

A systematic review of MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov was performed for studies assessing the prevalence of a complete YCM in oligozoospermic men in European and North American studies.

EVIDENCE SYNTHESIS

Thirty-seven studies were identified during a systematic review (n = 12 492 oligozoospermic men). All complete YCMs in oligozoospermic men were AZFc microdeletions. Eighteen studies contained data conducive to meta-analysis (n = 10 866 men). Comparing the pooled estimated prevalence by sperm concentration, complete YCMs were significantly more common in men with sperm concentrations of >0-1 million sperm/ml (5.0% [95% confidence interval {CI}: 3.6-6.8%]) versus >1-5 million sperm/ml (0.8% [95% CI: 0.5-1.3%], p < 0.001). YCMs were similar in men with sperm concentrations of >1-5 and >5-20 million sperm/ml (0.8% [95% CI: 0.5-1.3%] vs 0.5% [95% CI: 0.2-0.9%], p = 0.14).

CONCLUSIONS

In Europe and North America, the majority of YCMs occur in men with sperm concentrations of ≤1 million sperm/ml, with <1% identified in men with >1 million sperm/ml. Male infertility guidelines for North America and Europe should reconsider the sperm concentration screening thresholds to recommend testing for YCMs only for men with sperm concentrations of <1 million sperm/ml.

PATIENT SUMMARY

Complete Y-chromosome microdeletions (YCMs) are rare in men with >1 million sperm/ml. Routine screening for YCMs should occur only if sperm concentration is ≤1 million sperm/ml.

Cytogenetic and molecular characterization of an oligoasthenozoospermia male carrier of an unbalanced Y;22 translocation: A case report

RATIONALE

Y;autosome translocations are associated with male infertility and azoospermia. Some carriers with a Y:22 translocation can produce offspring and transmit the translocation through generations without phenotypic repercussion. Hence, the clinical features of carriers with certain Y chromosome abnormalities remain uncertain.

PATIENT CONCERNS

An apparently healthy 33-year-old man, 175 cm tall and weighing 60 kg had a 6-month history of primary infertility.

DIAGNOSES

The patient was diagnosed with oligoasthenozoospermia. A series of examinations have been performed to evaluate possible genetic causes of this diagnosis. Several methods included semen analysis, hormone measurements, cytogenetic analysis, and high-throughput multiplex ligation-dependent probe amplification semiconductor sequencing.

INTERVENTIONS

The patient underwent detailed genetic counseling. Cytogenetic analysis was advised for his father. Preimplantation genetic diagnosis was performed to improve potential pregnancy success rate.

OUTCOMES

Semen analysis revealed oligoasthenozoospermia. Hormone levels were within the normal limits. The karyotype of the patient and his father was 45,X,der(Y;22). Sequencing results indicated the presence of the sex-determining region on the Y chromosome gene. Y-chromosome microdeletion detection showed the presence of AZF (azoospermic factor)a, AZFb, and AZFc regions, but deletion of b2/b3 and duplication of b3/b4 regions.

LESSONS

A clinical karyotype report involving a Y chromosome abnormality should consider the results of semen analysis, which helps to identify the chromosomal breakpoint. Semiconductor sequencing technology was useful for clarifying AZF gene microdeletions.

Molecular and cytogenetic analysis of infertile Hakka men with azoospermia and severe oligozoospermia in southern China

OBJECTIVE

To determine the prevalence of chromosome abnormalities and azoospermia factor (AZF) microdeletions in Hakka men with infertility in southern China.

METHODS

Hakka male patients, who received clinical counselling for infertility between August 2016 and October 2017, and fertile male controls, were enrolled into this retrospective study. Patients diagnosed with infertility and controls underwent cytogenetic analysis by standard G-banding; AZF microdeletions were examined by multiplex polymerase chain reaction and capillary electrophoresis.

RESULTS

Out of 918 male patients who received fertility counselling, 57 were diagnosed with infertility due to azoospermia or severe oligozoospermia. Of these infertile patients, 22.81% (13/57) carried chromosome abnormalities, with 47, XXY being the most common abnormal karyotype. In addition, 36.84% (21/57) presented with Y chromosome microdeletions, most frequently in the complete AZFc and partial AZFc region. Duplication of the AZFc region was found in three patients. No AZF microdeletions were found in 60 fertile male controls.

CONCLUSION

The high AZF microdeletion frequency in the current Hakka population suggests that AZF microdeletion analysis is essential in fertility screening, and combined with cytogenetic analysis, may influence the choice of assisted reproductive techniques and reduce the risk of inherited genetic disease.

A novel stopgain mutation c.G992A (p.W331X) in TACR3 gene was identified in nonobstructive azoospermia by targeted next-generation sequencing

BACKGROUND

Nonobstructive azoospermia (NOA) is one of the most severe forms of male infertility because of impaired spermatogenesis with the absence of spermatozoa in the ejaculate. The causes of this disease can be partly attributed to genetic factors. Some common structural variants and single nucleotide polymorphisms (SNPs) were reported to be associated with NOA. However, the underlying etiology and genetic mechanism(s) remain largely unclear. The aim of this study was to investigate the associated mutations of spermatogenic genes in Chinese infertile men with NOA.

METHODS

The entire coding region of 25 genes associated with spermatogenesis was sequenced from 200 infertile men with NOA. Screening was carried out using the targeted exome sequencing to identify genetic variations and SNPs of the entire coding region of these genes.

RESULTS

After the targeted exome sequencing data were filtered through several currently existing variation databases, a series of variations were found. In this paper, we report one novel stopgain variation c.G992A (p.W331X) in the exon 4 of TACR3 gene. The variant was heterozygous and categorized as pathogenic.

CONCLUSION

In conclusion, our study revealed a novel stopgain mutation c.G992A (p.W331X) in TACR3 which expanded the mutation spectrum of TACR3 in Chinese NOA infertile men and advanced our understanding of the genetic susceptibility to NOA.

Human mitochondrial DNA haplogroup M8a influences the penetrance of m.8684C>T in Han Chinese men with non-obstructive azoospermia

RESEARCH QUESTION

What is the role of mitochondrial DNA (mtDNA) in the pathogenesis of non-obstructive azoospermia (NOA)?

DESIGN

mtDNA genome sequencing followed by an independent population validation were performed in 628 NOA cases and 584 healthy controls. Antioxidant capacity of serum was evaluated in 54 randomly selected cases out of 536 and 49 out of 489 controls.

RESULTS

In the screening stage, 13 mtDNA haplogroups (hg) were ascertained, and 10 susceptible variants were observed. In the validation stage, hg M8* in individuals was found to be associated with increased risk of NOA [odds ratio (OR) 2.61, 95% confidence interval (CI) 1.47-4.61] (P=0.001). Unexpectedly, the frequency of m.8684C>T, the defining marker for hg M8a, was also higher in NOA (OR 4.14, 95% CI 1.56-11.03) (P=0.002). Subsequently, the frequency distributions were compared among the sub-hg of hg M8* (including hg M8a, C and Z) and, intriguingly, no significance was found in hg C and Z. Additionally, the level of total antioxidant capacity was significantly decreased (P<0.05) compared with the control group.

CONCLUSIONS

hg M8a background in general played an active role in the penetrance of 8684C>T in NOA, and mtDNA genetic variants (causing low antioxidant levels) might increase mtDNA damage and impair normal spermatogenesis.

Novel distance-progesterone-combined selection approach improves human sperm quality

Background

Sperm selection is essential for the health of offspring conceived via assistive reproductive technology (ART). Various methods of sperm preparation for in vitro fertilization and intracytoplasmic sperm injection have been developed to acquire sperm with better quality and to avoid potential genetic disorders. However, current sperm processing and selection techniques bypass the natural selection that occurs during fertilization in vivo. The aim of this study was to present a novel distance-progesterone-combined selection approach with an original device based on the human female reproductive tract, and to report on its effectiveness based on sperm progressive motility, as well as chemotaxis.

Methods

A novel device with long distance channels which mimicked the female human reproductive system was designed and fabricated. This ready-to-be-used device was developed using a progesterone gradient and human tube fluid media. Sperm swam for 150 min in the device under conditions of 37 °C air temperature with 5% CO₂ after separation from seminal plasma via discontinuous Percoll gradient treatment. The selected sperm were assessed for normal morphology using Diff-Quik staining. A chromatin diffusion assay assessed sperm for DNA fragments and apoptosis was assessed using annexin V-fluorescein isothiocyanate/propidium iodide fluorescent staining.

Results

Our distance-progesterone-combined sperm selection method was successfully established. After sperm were selected, the percentage of sperm with normal morphology increased (before vs. after selection, 11.2 ± 1.3% vs. 40.3 ± 6.6%, P = 0.000), the percentage of sperm with DNA fragmentation decreased (before vs. after selection, 15.4 ± 4.0% vs. 6.8 ± 3.3%, P = 0.001), and the percentage of sperm with apoptosis did not change significantly.

Conclusions

Our newly-developed method is capable of successfully selecting sperm of high quality. The method will be benefit clinical ART practice as it can reduce sperm-related genetic risks.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1575-7) contains supplementary material, which is available to authorized users.

Telomeres as a molecular marker of male infertility

In recent years, male infertility has become a growing social problem. Standard diagnostic procedures, based on assessing seminological parameters, are often insufficient to explain the causes of male infertility. Because of this, new markers with better clinical application are being sought. One of the promising markers seems to be an assessment of telomere length of sperm. Sperm telomeres, in contrast to somatic cells, are elongated as men age. The results of some studies suggest that telomere length may be relevant in the case of fertilization and normal embryo development. Literature reports indicate that there is a correlation between telomere length of sperm and abnormal sperm parameters. The measurement of telomere length using the method of quantitative PCR could become a new marker of spermatogenesis, which can be useful for evaluating male reproductive age.

An infertile patient with Y chromosome b1/b3 deletion presenting with congenital bilateral absence of the vas deferens with normal spermatogenesis

We report the case of a 46-year-old Chinese male patient who visited our clinic complaining of infertility. Semen analysis revealed azoospermia, and azoospermia factor c region partial deletion (b1/b3) was detected using Y chromosome microdeletion analysis. Testicular sperm extraction was performed after genetic counseling. The bilateral ductus deferens and a portion of the epididymis were absent, whereas the remaining epididymis was expanded. Motile intratesticular spermatozoa were successfully extracted from the seminiferous tubule. On histopathology, nearly complete spermatogenesis was confirmed in almost every seminiferous tubule. To our knowledge, this is the first case report of b1/b3 deletion with a congenital bilateral absence of the vas deferens and almost normal spermatogenesis.

Outcome of Oocyte Vitrification Combined with Microdissection Testicular Sperm Extraction and Aspiration for Assisted Reproduction in Men

Background

As a safety and efficacy protocol, oocyte vitrification has been widely used in IVF treatment. The aim of this study was to evaluate the outcome of ICSI-ET utilizing vitrified oocytes with sperm obtained from non-obstructive azoospermia (NOA) patients via micro-TESE.

Material/Methods

A total of 150 NOA patients underwent micro-TESE. Ten patients were unable to ejaculate and refused to accept TESA at the time of oocyte retrieval; later, these patients underwent TESA. A total of 174 obstructive azoospermia (OA) patients underwent TESA. Vitrified oocytes were used with micro-TESE in 35 cycles (group 1), and TESA in 10 cycles (group 2). Fresh oocytes were used with micro-TESE in 38 cycles (group 3) and TESA in 174 cycles (group 4).

Results

The overall sperm retrieval rate of the 150 NOA patients was 48.7% (73/150). A total of 257 cycles of ICSI-ET were conducted with testicular spermatozoa; 212 cycles utilized fresh oocytes and 45 cycles utilized vitrified oocytes. No differences were observed with fertilization (73.8%, 77.2%,72.8%, 73.6%), implantation (33.3%, 34.7%, 33.8%, 37.5%), or clinical pregnancy rates (51.4%, 60%, 52.6%, 51.7%) for groups 1 through 4, respectively (P>0.05). Developmental competence was greatest among couples using sperm obtained via TESA rather than micro-TESE, not dependent on whether vitrified or fresh oocytes were utilized. Fertilization, implantation, and clinical pregnancy rates did not differ between using fresh vs. vitrified oocytes, nor did they differ between using testicular sperm derived from men with NOA vs. men with OA.

Conclusions

Vitrified oocytes combined with micro-TESE showed similar clinical efficacy when compared with fresh oocytes.

Molecular analysis of CAG repeat length of the androgen receptor gene and Y chromosome microdeletions among Jordanian azoospermic infertile males

Assisted reproductive technology is a common procedure which helps millions of couples who suffer fertility problems worldwide every year. Screening for genetic abnormalities prior to such procedure is very important to prevent the transmission of harmful genetic mutations to future generations. Microdeletions within the azoospermia factor (AZF) region of the Y chromosome and the expansion of the CAG trinucleotides in the androgen receptor (AR) gene are among the susceptible causes of male infertility in different ethnic groups. Such association has never been studied in Jordan. In this study, we compared CAG repeat length between azoospermic infertile and normospermic fertile Jordanian males and we also screened the frequency of Y chromosome microdeletions in the same cohort. The study included 142 nonobstructive azoospermic cases and 145 normospermic controls. Results have shown that the median CAG repeat length in the azoospermic group is 19 ± 2 compared to 19 ± 1.5 (p = .6262) in the control group. Deletions within the Y chromosome AZF region were detected in 7 of 142 cases (4.93%) and no deletions were seen in the control group. The results of this study confirm the importance of the AZF region in normal spermatogenesis, whereas it shows no link between the length of CAG repeats in the AR gene and male azoospermia in Jordanian group examined.

A report of nine cases and review of the literature of infertile men carrying balanced translocations involving chromosome 5

Background

Balanced translocations may cause the loss of genetic material at the breakpoints and may result in failure of spermatogenesis. However, carriers of reciprocal translocation may naturally conceive. Genetic counseling of male carriers of translocations remains challenging. This study explores the clinical features of carriers of chromosome 5 translocations, enabling informed genetic counseling of these patients.

Results

Of 82 translocation carriers, 9 (11%) were carriers of a chromosome 5 translocation. One case had azoospermia, while three cases had experienced recurrent spontaneous abortions, two cases had each experienced stillbirth, and three cases produced a phenotypically normal child confirmed by amniocentesis. A literature review identified 106 patients who carried chromosome 5 translocations. The most common chromosome 5 translocation was t(4,5), observed in 13 patients. Breakpoint at 5p15 was observed in 11 patients. All breakpoints at chromosome 5 were associated with gestational infertility.

Conclusion

In genetic counseling, physicians should consider chromosome 5 and its breakpoints. Carriers of chromosome 5 translocations may continue with natural conception or use assisted reproductive technologies, such as preimplantation genetic diagnosis.

Anti-Mullerian Hormone-to-Testosterone Ratio is Predictive of Positive Sperm Retrieval in Men with Idiopathic Non-Obstructive Azoospermia

The lack of clinically-reliable biomarkers makes impossible to predict sperm retrieval outcomes at testicular sperm extraction (TESE) in men with non-obstructive azoospermia (NOA), resulting in up to 50% of unnecessary surgical interventions. Clinical data, hormonal profile and histological classification of testis parenchyma from 47 white-Caucasian idiopathic NOA (iNOA) men submitted to microdissection TESE (microTESE) were analyzed. Logistic regression analyses tested potential clinical predictors of positive sperm retrieval. The predictive accuracy of all variables was evaluated using the receiver operating characteristic-derived area under the curve, and the clinical net benefit estimated by a decision-curve analysis (DCA). Overall, 23 (49%) and 24 (51%) patients were classified as positive and negative sperm retrievals at microTESE. While circulating hormones associated to a condition of primary hypogonadism did not predict sperm retrieval, levels of anti-Mullerian hormone (AMH) and the ratio AMH-to-total Testosterone (AMH/tT) achieved independent predictor status for sperm retrieval at microTESE, with a predictive accuracy of 93% and 95%. Using cutoff values of <4.62 ng/ml for AMH and <1.02 for AMH/tT, positive sperm retrieval was predicted in all individuals, with 19 men out of 47 potentially spared from surgery. DCA findings demonstrated clinical net benefit using AMH and AMH/tT for patient selection at microTESE.

Association of the common SNPs in RNF212, STAG3 and RFX2 gene with male infertility with azoospermia in Chinese population

OBJECTIVE

The aim of this study was to explore the association between the SNP rs4045481 in RNF212 gene, rs1050482 and rs11531577 in STAG3 gene as well as rs2288846 in RFX2 gene and male infertility with azoospermia in Chinese population.

STUDY DESIGN

Two hundreds and twenty infertile patients with azoospermia and 248 fertile men were recruited in the present study. The four SNPs investigated were genotyped using polymerase chain reaction and restriction fragment length polymorphism assay. The differences in allelic and genotypic frequencies between patients and controls were evaluated by chi-square test.

RESULTS

No significant differences in allele and genotype frequencies of SNP rs1050482 and rs11531577 in STAG3 gene as well as rs2288846 in RFX2 gene between patients with azoospermia and controls were observed. However, the frequencies of allele C(43.6% vs. 34.1%, P = 0.003, OR = 1.498, 95% CI 1.150-1.192) and genotype CC (24.6% vs. 12.0%, P = 0.001, OR = 2.346, 95% CI 1.448-3.858) were significantly higher in patients with azoospermia than those in controls at the rs4045481 locus in RNF212 gene.

CONCULUSION

The polymorphism of SNP rs4045481 in RNF212 gene might be associated with azoospermia and genotype CC of this SNP may be a risk factor of azoospermia.

Effects of the insulin-like growth factor system on testicular differentiation and function: a review of the literature

We recently described the occurrence of cryptorchidism, oligoasthenoteratozoospermia, and genital abnormalities in patients with distal 15q chromosome structural abnormalities. This observation brought us to hypothesize that insulin-like growth factor (IGF) receptor (IGF1R), mapping on the 15q 26.3 chromosomal band, may be involved in testicular function. To further evaluate this topic, we reviewed in vitro and in vivo studies exploring the role of the IGF system [IGF1, IGF2, IGF1R, insulin receptor substrates (IRS)] at the testicular level both in animals and in humans. In animals, IGF1/IGF1R has been found to be involved in testicular development during embryogenesis, in Sertoli cell (SC) proliferation, and in germ cell (GS) proliferation and differentiation. Interestingly, IGF1R seems to mediate follicle-stimulating hormone (FSH) effects through the PI3K/AKT pathway. In humans, IGF1 directly increases testicular volume. The molecular pathways responsible for testicular differentiation and IGF1/IGF1R signaling are highly conserved among species; therefore, the IGF system may be involved in FSH signaling also in humans. We suggest a possible molecular pathway occurring in human SCs, which involves both IGF1 and FSH through the PI3K/AKT pathway. The acknowledgment of an IGF1 mediation of the FSH-induced effects may open new ways for a targeted therapy in idiopathic non-FSH-responder oligoasthenoteratozoospermia.

Associations of C677T polymorphism in methylenetetrahydrofolate reductase (MTHFR) gene with male infertility risk: A meta-analysis

PURPOSE

Methylenetetrahydrofolate reductase is one of the key enzymes in folate metabolism. But the association between polymorphism and the risk of male infertility is still controversial. Therefore, this study used a meta-analysis on the collection of data to analyze MTHFR gene C677T polymorphism (known as c.665 C>T, rs1801133, p.Ala222Val).

METHODS

PubMed, EMBASE, China National Knowledge Infrastructure (CNKI), and Wan fang. Data were searched to identify eligible studies. We sifted the data collection by Hardy-Weinberg equilibrium calculator and used odds ratios (ORs) and 95% confidence intervals (95% CIs) to conduct data through RevMan5.0 and StataSE12.0 software.

RESULTS

A total of 15 studies have 3853 patients with infertility and 3613 healthy controls in this meta-analysis. Our results showed that T variant of MTHFR C677T gene polymorphism was significantly associated with an increased risk of male infertility (forT vs. C: OR=1.38, 95% CI=1.18-1.63; for TT vs. CC: OR=1.86, 95% CI=1.36-2.54; for CT vs. CC: OR=1.34, 95% CI=1.03-1.74; for TT vs. CT: OR=1.52, 95% CI=1.26-1.84; for TT vs. CT+CC: OR=1.42, 95% CI=1.19-1.70; for TT+CT versus CC: OR=1.46, 95%CI=1.05-2.04). In addition, the results indicated that T allele had the positive association which was driven by East-asian populations (random: OR=1.44, 95% CI=1.2-1.74; fixed: OR=1.39, 95% CI=1.20-1.61), Middle-eastern populations (random: OR=1.30, 95% CI=1.05-1.63; fixed: OR=1.30, 95% CI=1.05-1.63) and Mixed-race (random: OR=1.96, 95% CI=1.35-2.85; fixed: OR=1.31, 95% CI=1.20-1.43).

CONCLUSION

This meta-analysis suggests that MTHFR C677T polymorphism is associated with male infertility.

New era of cystic fibrosis: Full mutational analysis and personalized therapy

Despite its apparently simple genetics, cystic fibrosis (CF) is a rather complex genetic disease. A lot of variability in the steps of the path from the cystic fibrosis transmembrane conductance regulator (CFTR) gene to the clinical manifestations originates an uncertain genotype - phenotype relationship. A major determinant of this uncertainty is the incomplete knowledge of the CFTR mutated genotypes, due to the high number of CFTR mutations and to the higher number of their combinations in trans and in cis. Also the very limited knowledge of functional effects of CFTR mutated alleles severely impairs our diagnostic and prognostic ability. The final phenotypic modulation exerted by CFTR modifier genes and interactome further complicates the framework. The next generation sequencing approach is a rapid, low-cost and high-throughput tool that allows a near complete structural characterization of CFTR mutated genotypes, as well as of genotypes of several other genes cooperating to the final CF clinical manifestations. This powerful method perfectly complements the new personalized therapeutic approach for CF. Drugs active on specific CFTR mutational classes are already available for CF patients or are in phase 3 trials. A complete genetic characterization has been becoming crucial for a correct personalized therapy. However, the need of a functional classification of each CFTR mutation potently arises. Future big efforts towards an ever more detailed knowledge of both structural and functional CFTR defects, coupled to parallel personalized therapeutic interventions decisive for CF cure can be foreseen.

Relationship between Chlamydia-Ureaplasma-Mycoplasma Genital Detection with Semen Concentration and Motility among Greek Men

One hundred and seventy two men at the State of Thessaly, Greece, inquiring semen analysis were enrolled in the study in order to investigate the incidence of Chlamydia, Ureaplasma and Mycoplasma (C-U-M) genera in respect to total sperm number (TSN), progressive motility (grades a and b) and total motility (grades a, b and c). Putative relation of C-U-M acquirement with sexual behavior was also investigated. Incidence of C-U-M among non-oligozoospermic and oligozoospermic men was similar. Νο correlation of C-U-M carriage to either oligozoospermia or asthenozoospermia was found. The tested semen parameters were negatively correlated to the age of sexual intercourse initiation and positively correlated to the number of sex partners. Early age of sexual intercourse initiation or high number of sexual partners was not statistical significantly correlated to C-U-M acquirement. Overall, TSN and motility (either progressive or total) were not influenced by the presence of C-U-M genera in a sample of Greek population undergoing semen evaluation. To distinguish the role of C-U-M in male infertility and clarify the so far controversial scarce literature, large control case studies are needed using nucleic acid amplification techniques to detect these pathogens.

Factors associated with aberrant imprint methylation and oligozoospermia

Disturbingly, the number of patients with oligozoospermia (low sperm count) has been gradually increasing in industrialized countries. Epigenetic alterations are believed to be involved in this condition. Recent studies have clarified that intrinsic and extrinsic factors can induce epigenetic transgenerational phenotypes through apparent reprogramming of the male germ line. Here we examined DNA methylation levels of 22 human imprinted loci in a total of 221 purified sperm samples from infertile couples and found methylation alterations in 24.8% of the patients. Structural equation model suggested that the cause of imprint methylation errors in sperm might have been environmental factors. More specifically, aberrant methylation and a particular lifestyle (current smoking, excess consumption of carbonated drinks) were associated with severe oligozoospermia, while aging probably affected this pathology indirectly through the accumulation of PCB in the patients. Next we examined the pregnancy outcomes for patients when the sperm had abnormal imprint methylation. The live-birth rate decreased and the miscarriage rate increased with the methylation errors. Our research will be useful for the prevention of methylation errors in sperm from infertile men, and sperm with normal imprint methylation might increase the safety of assisted reproduction technology (ART) by reducing methylation-induced diseases of children conceived via ART.

Methylenetetrahydrofolate Reductase C677T Polymorphism and Risk for Male Infertility in Asian Population

Methylenetetrahydrofolate reductase (MTHFR) is a critical enzyme of folate pathway and required for DNA synthesis and methylation. MTHFE C677T polymorphisms is reported as risk factors for various diseases and disorders like birth defects, metabolic, neurological, psychiatric disorders, and cancers. Several studies have investigated association between the MTHFR C677T polymorphism and male infertility. To assess the risk associated with MTHFR C677T polymorphism in Asian population, a meta-analysis was performed. Included articles were collected from the following electronic databases: PubMed, Google Scholar, and Science direct up to March 2015. Risk was estimated as pooled odds ratios (ORs) with confidence intervals (CIs) for assessment. Seventeen case-control studies involving 4392 breast infertile males and 3667 fertile males were found suitable for the inclusion in the present meta-analysis. Results showed that the C677T polymorphism was significantly associated with male infertility in Asian population using all the five genetic models (OR_{T vs. C} (allele contrast model) = 1.86, 95% CI 1.7-2.0; OR_{TT vs. CC} (homozygote model) = 1.96, 95% CI 1.67-2.30; OR_{CT vs. CC} (co-dominant model) = 1.40, 95% CI 1.18-1.62; OR_{TT+CT vs. CC} (dominant model) = 1.53, 95% CI 1.30-1.77; OR_{TT vs. CT+CC} (recessive model) = 1.67, 95% CI 1.44-1.92). In conclusion, results of present meta-analysis strongly supported an association between C677T polymorphism and male infertility in Asians.

Recent advances in the genetics of testicular failure

Infertility affects approximately 15% of couples, and male factor is responsible for 30%-50% of all infertility. The most severe form of male infertility is testicular failure, and the typical phenotype of testicular failure is severely impaired spermatogenesis resulting in azoospermia or severe oligozoospermia. Although the etiology of testicular failure remains poorly understood, genetic factor typically is an underlying cause. Modern assisted reproductive techniques have revolutionized the treatment of male factor infertility, allowing biological fatherhood to be achieved by many men who would otherwise have been unable to become father to their children through natural conception. Therefore, identifying genetic abnormalities in male is critical because of the potential risk of transmission of genetic abnormalities to the offspring. Recently, along with other intense researches ongoing, whole-genome approaches have been used increasingly in the genetic studies of male infertility. In this review, we focus on the genetics of testicular failure and provide an update on the advances in the study of genetics of male infertility.

Screening of Two Neighboring CFTR Mutations in Iranian Infertile Men with Non-Obstructive Azoospermia

The genetic association between cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations and male infertility due to congenital bilateral absence of vas deferens (CBAVD) is well established. Mutant CFTR, however may also be involved in the etiology of male infertility in non-CBAVD cases. The present study was conducted to estimate the frequency of ∆I507 and ∆F508 CFTR gene mutations in Iranian infertile males. We undertook the first study of association between these CFTR mutations and non-obstructive azoospermia in Iran. In this case-control study, 100 fertile healthy fathers and 100 non-obstructive azoospermia’s men were recruited from Isfahan Infertility Center (IIC) and Sari Saint Mary’s Infertility Center, between 2008 and 2009. Screening of F508del and I507del mutations was carried out by the multiplex-ARMS-PCR. Significance of differences in mutation frequencies between the patient and control groups was assessed by Fisher’s exact test. The ΔF508 was detected in three patients. However there are no significant association was found between the presence of this mutated allele and infertility [OR=9.2 (allele-based) and 7.2 (individual-based), P=0.179]. None of the samples carried the ΔI507 mutation. Altogether, we show that neither ΔI507 nor ΔF508 is involved in this population of Iranian infertile males with non-obstructive azoospermia.