The piRNA-pathway factor FKBP6 is essential for spermatogenesis but dispensable for control of meiotic LINE-1 expression in humans.

Infertility affects around 7% of the male population and can be due to severe spermatogenic failure (SPGF), resulting in no or very few sperm in the ejaculate. We initially identified a homozygous frameshift variant in FKBP6 in a man with extreme oligozoospermia. Subsequently, we screened a total of 2,699 men with SPGF and detected rare bi-allelic loss-of-function variants in FKBP6 in five additional persons. All six individuals had no or extremely few sperm in the ejaculate, which were not suitable for medically assisted reproduction. Evaluation of testicular tissue revealed an arrest at the stage of round spermatids. Lack of FKBP6 expression in the testis was confirmed by RT-qPCR and immunofluorescence staining. In mice, Fkbp6 is essential for spermatogenesis and has been described as being involved in piRNA biogenesis and formation of the synaptonemal complex (SC). We did not detect FKBP6 as part of the SC in normal human spermatocytes, but small RNA sequencing revealed that loss of FKBP6 severely impacted piRNA levels, supporting a role for FKBP6 in piRNA biogenesis in humans. In contrast to findings in piRNA-pathway mouse models, we did not detect an increase in LINE-1 expression in men with pathogenic FKBP6 variants. Based on our findings, FKBP6 reaches a "strong" level of evidence for being associated with male infertility according to the ClinGen criteria, making it directly applicable for clinical diagnostics. This will improve patient care by providing a causal diagnosis and will help to predict chances for successful surgical sperm retrieval.

Antioxidants for male subfertility.

BACKGROUND: The inability to have children affects 10% to 15% of couples worldwide. A male factor is estimated to account for up to half of the infertility cases with between 25% to 87% of male subfertility considered to be due to the effect of oxidative stress. Oral supplementation with antioxidants is thought to improve sperm quality by reducing oxidative damage. Antioxidants are widely available and inexpensive when compared to other fertility treatments, however most antioxidants are uncontrolled by regulation and the evidence for their effectiveness is uncertain. We compared the benefits and risks of different antioxidants used for male subfertility. OBJECTIVES: To evaluate the effectiveness and safety of supplementary oral antioxidants in subfertile men. SEARCH METHODS: The Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase, PsycINFO, AMED, and two trial registers were searched on 15 February 2021, together with reference checking and contact with experts in the field to identify additional trials. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared any type, dose or combination of oral antioxidant supplement with placebo, no treatment, or treatment with another antioxidant, among subfertile men of a couple attending a reproductive clinic. We excluded studies comparing antioxidants with fertility drugs alone and studies that included men with idiopathic infertility and normal semen parameters or fertile men attending a fertility clinic because of female partner infertility. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. The primary review outcome was live birth. Clinical pregnancy, adverse events and sperm parameters were secondary outcomes. MAIN RESULTS: We included 90 studies with a total population of 10,303 subfertile men, aged between 18 and 65 years, part of a couple who had been referred to a fertility clinic and some of whom were undergoing medically assisted reproduction (MAR). Investigators compared and combined 20 different oral antioxidants. The evidence was of 'low' to 'very low' certainty: the main limitation was that out of the 67 included studies in the meta-analysis only 20 studies reported clinical pregnancy, and of those 12 reported on live birth. The evidence is current up to February 2021. Live birth: antioxidants may lead to increased live birth rates (odds ratio (OR) 1.43, 95% confidence interval (CI) 1.07 to 1.91, P = 0.02, 12 RCTs, 1283 men, I2 = 44%, very low-certainty evidence). Results in the studies contributing to the analysis of live birth rate suggest that if the baseline chance of live birth following placebo or no treatment is assumed to be 16%, the chance following the use of antioxidants is estimated to be between 17% and 27%. However, this result was based on only 246 live births from 1283 couples in 12 small or medium-sized studies. When studies at high risk of bias were removed from the analysis, there was no evidence of increased live birth (Peto OR 1.22, 95% CI 0.85 to 1.75, 827 men, 8 RCTs, P = 0.27, I2 = 32%). Clinical pregnancy rate: antioxidants may lead to increased clinical pregnancy rates (OR 1.89, 95% CI 1.45 to 2.47, P < 0.00001, 20 RCTs, 1706 men, I2 = 3%, low-certainty evidence) compared with placebo or no treatment. This suggests that, in the studies contributing to the analysis of clinical pregnancy, if the baseline chance of clinical pregnancy following placebo or no treatment is assumed to be 15%, the chance following the use of antioxidants is estimated to be between 20% and 30%. This result was based on 327 clinical pregnancies from 1706 couples in 20 small studies. Adverse events Miscarriage: only six studies reported on this outcome and the event rate was very low. No evidence of a difference in miscarriage rate was found between the antioxidant and placebo or no treatment group (OR 1.46, 95% CI 0.75 to 2.83, P = 0.27, 6 RCTs, 664 men, I2 = 35%, very low-certainty evidence). The findings suggest that in a population of subfertile couples, with male factor infertility, with an expected miscarriage rate of 5%, the risk of miscarriage following the use of an antioxidant would be between 4% and 13%. Gastrointestinal: antioxidants may lead to an increase in mild gastrointestinal discomfort when compared with placebo or no treatment (OR 2.70, 95% CI 1.46 to 4.99, P = 0.002, 16 RCTs, 1355 men, I2 = 40%, low-certainty evidence). This suggests that if the chance of gastrointestinal discomfort following placebo or no treatment is assumed to be 2%, the chance following the use of antioxidants is estimated to be between 2% and 7%. However, this result was based on a low event rate of 46 out of 1355 men in 16 small or medium-sized studies, and the certainty of the evidence was rated low and heterogeneity was high. We were unable to draw conclusions from the antioxidant versus antioxidant comparison as insufficient studies compared the same interventions. AUTHORS' CONCLUSIONS: In this review, there is very low-certainty evidence from 12 small or medium-sized randomised controlled trials suggesting that antioxidant supplementation in subfertile males may improve live birth rates for couples attending fertility clinics. Low-certainty evidence suggests that clinical pregnancy rates may increase. There is no evidence of increased risk of miscarriage, however antioxidants may give more mild gastrointestinal discomfort, based on very low-certainty evidence. Subfertile couples should be advised that overall, the current evidence is inconclusive based on serious risk of bias due to poor reporting of methods of randomisation, failure to report on the clinical outcomes live birth rate and clinical pregnancy, often unclear or even high attrition, and also imprecision due to often low event rates and small overall sample sizes. Further large well-designed randomised placebo-controlled trials studying infertile men and reporting on pregnancy and live births are still required to clarify the exact role of antioxidants.

Bi-allelic Mutations in M1AP Are a Frequent Cause of Meiotic Arrest and Severely Impaired Spermatogenesis Leading to Male Infertility.

Male infertility affects ∼7% of men, but its causes remain poorly understood. The most severe form is non-obstructive azoospermia (NOA), which is, in part, caused by an arrest at meiosis. So far, only a few validated disease-associated genes have been reported. To address this gap, we performed whole-exome sequencing in 58 men with unexplained meiotic arrest and identified the same homozygous frameshift variant c.676dup (p.Trp226LeufsTer4) in M1AP, encoding meiosis 1 associated protein, in three unrelated men. This variant most likely results in a truncated protein as shown in vitro by heterologous expression of mutant M1AP. Next, we screened four large cohorts of infertile men and identified three additional individuals carrying homozygous c.676dup and three carrying combinations of this and other likely causal variants in M1AP. Moreover, a homozygous missense variant, c.1166C>T (p.Pro389Leu), segregated with infertility in five men from a consanguineous Turkish family. The common phenotype between all affected men was NOA, but occasionally spermatids and rarely a few spermatozoa in the semen were observed. A similar phenotype has been described for mice with disruption of M1ap. Collectively, these findings demonstrate that mutations in M1AP are a relatively frequent cause of autosomal recessive severe spermatogenic failure and male infertility with strong clinical validity.

Improved detection of CFTR variants by targeted next-generation sequencing in male infertility: a case series.

RESEARCH QUESTION: Congenital bilateral absence of vas deferens (CBAVD) is characterized by 'obstructive azoospermia' in male patients with primary infertility. In the routine clinical workup of infertile men, patients with an absence of vas deferens are screened for CFTR variants. However, current genetic testing panels do not cover all variants, missing some CBAVD cases. Here, CFTR testing was explored by targeted next-generation sequencing (NGS) to improve variant detection. DESIGN: Five individuals with heterozygous pathogenic CFTR variants were identified using targeted NGS in a cohort of 1112 idiopathic infertile men with azoospermia or severe oligozoospermia. Pre-screening exclusion criteria were CBAVD by clinical examination with positive CFTR sequence analysis as part of routine fertility workup. RESULTS: Cases 1, 2 and 3 presented with CBAVD after which CFTR screening by mutation panel analysis was negative. Case 4 presented with congenital unilateral absence of vas deferens, after which CFTR panel analysis identified a heterozygous p.(Phe508del) variant. Case 5 presented with a palpable vas deferens so CFTR panel analysis was not offered. In all five men, targeted NGS revealed additional pathogenic variants: p.(Arg117Cys) and p.(Arg1158*) (case 1); p.(Asp110His) and p.(Ser945Leu) (case 2); p.(Arg248Thr) and p.(Phe508Cys) (case 3); p.(Gly463Ser) (case 4); p.(Phe508del) (case 4 and 5); and p.(Arg117His) (case 5). CONCLUSIONS: Targeted NGS led to the detection of five infertile men with CFTR variants who would otherwise have remained undiagnosed after routine genetic screening during the fertility workup for azoospermia or severe oligozoospermia. Given the wide availability of affordable targeted NGS, the data suggest that full gene analysis, and not mutation panels, should be considered to screen CFTR in azoospermic men.

A systematic review and standardized clinical validity assessment of male infertility genes.

STUDY QUESTION: Which genes are confidently linked to human monogenic male infertility? SUMMARY ANSWER: Our systematic literature search and clinical validity assessment reveals that a total of 78 genes are currently confidently linked to 92 human male infertility phenotypes. WHAT IS KNOWN ALREADY: The discovery of novel male infertility genes is rapidly accelerating with the availability of next-generating sequencing methods, but the quality of evidence for gene-disease relationships varies greatly. In order to improve genetic research, diagnostics and counseling, there is a need for an evidence-based overview of the currently known genes. STUDY DESIGN, SIZE, DURATION: We performed a systematic literature search and evidence assessment for all publications in Pubmed until December 2018 covering genetic causes of male infertility and/or defective male genitourinary development. PARTICIPANTS/MATERIALS, SETTING, METHODS: Two independent reviewers conducted the literature search and included papers on the monogenic causes of human male infertility and excluded papers on genetic association or risk factors, karyotype anomalies and/or copy number variations affecting multiple genes. Next, the quality and the extent of all evidence supporting selected genes was weighed by a standardized scoring method and used to determine the clinical validity of each gene-disease relationship as expressed by the following six categories: no evidence, limited, moderate, strong, definitive or unable to classify. MAIN RESULTS AND THE ROLE OF CHANCE: From a total of 23 526 records, we included 1337 publications about monogenic causes of male infertility leading to a list of 521 gene-disease relationships. The clinical validity of these gene-disease relationships varied widely and ranged from definitive (n = 38) to strong (n = 22), moderate (n = 32), limited (n = 93) or no evidence (n = 160). A total of 176 gene-disease relationships could not be classified because our scoring method was not suitable. LARGE SCALE DATA: Not applicable. LIMITATIONS, REASONS FOR CAUTION: Our literature search was limited to Pubmed. WIDER IMPLICATIONS OF THE FINDINGS: The comprehensive overview will aid researchers and clinicians in the field to establish gene lists for diagnostic screening using validated gene-disease criteria and help to identify gaps in our knowledge of male infertility. For future studies, the authors discuss the relevant and important international guidelines regarding research related to gene discovery and provide specific recommendations for the field of male infertility. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by a VICI grant from The Netherlands Organization for Scientific Research (918-15-667 to J.A.V.), the Royal Society, and Wolfson Foundation (WM160091 to J.A.V.) as well as an investigator award in science from the Wellcome Trust (209451 to J.A.V.). PROSPERO REGISTRATION NUMBER: None.

Antioxidants for male subfertility.

BACKGROUND: The inability to have children affects 10% to 15% of couples worldwide. A male factor is estimated to account for up to half of the infertility cases with between 25% to 87% of male subfertility considered to be due to the effect of oxidative stress. Oral supplementation with antioxidants is thought to improve sperm quality by reducing oxidative damage. Antioxidants are widely available and inexpensive when compared to other fertility treatments, however most antioxidants are uncontrolled by regulation and the evidence for their effectiveness is uncertain. We compared the benefits and risks of different antioxidants used for male subfertility. This review did not examine the use of antioxidants in normospermic men. OBJECTIVES: To evaluate the effectiveness and safety of supplementary oral antioxidants in subfertile men. SEARCH METHODS: The Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and two trials registers were searched on 1 February 2018, together with reference checking and contact with study authors and experts in the field to identify additional trials. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared any type, dose or combination of oral antioxidant supplement with placebo, no treatment or treatment with another antioxidant, among subfertile men of a couple attending a reproductive clinic. We excluded studies comparing antioxidants with fertility drugs alone and studies that included fertile men attending a fertility clinic because of female partner infertility. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. The primary review outcome was live birth. Clinical pregnancy, adverse events and sperm parameters were secondary outcomes. MAIN RESULTS: We included 61 studies with a total population of 6264 subfertile men, aged between 18 and 65 years, part of a couple who had been referred to a fertility clinic and some of whom were undergoing assisted reproductive techniques (ART). Investigators compared and combined 18 different oral antioxidants. The evidence was of 'low' to 'very low' quality: the main limitation was that out of the 44 included studies in the meta-analysis only 12 studies reported on live birth or clinical pregnancy. The evidence is current up to February 2018.Live birth: antioxidants may lead to increased live birth rates (OR 1.79, 95% CI 1.20 to 2.67, P = 0.005, 7 RCTs, 750 men, I2 = 40%, low-quality evidence). Results suggest that if in the studies contributing to the analysis of live birth rate, the baseline chance of live birth following placebo or no treatment is assumed to be 12%, the chance following the use of antioxidants is estimated to be between 14% and 26%. However, this result was based on only 124 live births from 750 couples in seven relatively small studies. When studies at high risk of bias were removed from the analysis, there was no evidence of increased live birth (Peto OR 1.38, 95% CI 0.89 to 2.16; participants = 540 men, 5 RCTs, P = 0.15, I2 = 0%).Clinical pregnancy rate: antioxidants may lead to increased clinical pregnancy rates (OR 2.97, 95% CI 1.91 to 4.63, P < 0.0001, 11 RCTs, 786 men, I2 = 0%, low-quality evidence) compared to placebo or no treatment. This suggests that if in the studies contributing to the analysis of clinical pregnancy, the baseline chance of clinical pregnancy following placebo or no treatment is assumed to be 7%, the chance following the use of antioxidants is estimated to be between 12% and 26%. This result was based on 105 clinical pregnancies from 786 couples in 11 small studies.Adverse eventsMiscarriage: only three studies reported on this outcome and the event rate was very low. There was no difference in miscarriage rate between the antioxidant and placebo or no treatment group (OR 1.74, 95% CI 0.40 to 7.60, P = 0.46, 3 RCTs, 247 men, I2 = 0%, very low-quality evidence). The findings suggest that in a population of subfertile men with an expected miscarriage rate of 2%, the chance following the use of an antioxidant would result in the risk of a miscarriage between 1% and 13%.Gastrointestinal: antioxidants may lead to an increase in mild gastrointestinal upsets when compared to placebo or no treatment (OR 2.51, 95% CI 1.25 to 5.03, P = 0.010, 11 RCTs, 948 men, I2 = 50%, very low-quality evidence). This suggests that if the chance of gastrointestinal upsets following placebo or no treatment is assumed to be 2%, the chance following the use of antioxidants is estimated to be between 2% and 9%. However, this result was based on a low event rate of 35 out of 948 men in 10 small or medium-sized studies, and the quality of the evidence was rated very low and was high in heterogeneity.We were unable to draw any conclusions from the antioxidant versus antioxidant comparison as insufficient studies compared the same interventions. AUTHORS' CONCLUSIONS: In this review, there is low-quality evidence from seven small randomised controlled trials suggesting that antioxidant supplementation in subfertile males may improve live birth rates for couples attending fertility clinics. Low-quality evidence suggests that clinical pregnancy rates may also increase. Overall, there is no evidence of increased risk of miscarriage, however antioxidants may give more mild gastrointestinal upsets but the evidence is of very low quality. Subfertilte couples should be advised that overall, the current evidence is inconclusive based on serious risk of bias due to poor reporting of methods of randomisation, failure to report on the clinical outcomes live birth rate and clinical pregnancy, often unclear or even high attrition, and also imprecision due to often low event rates and small overall sample sizes. Further large well-designed randomised placebo-controlled trials reporting on pregnancy and live births are still required to clarify the exact role of antioxidants.

Complication rate of uterine morcellation in laparoscopic supracervical hysterectomy: a retrospective cohort study.

BACKGROUND: Over the last decades minimally invasive surgical techniques are increasingly used to treat symptomatic leiomyomas, providing the patient decreased morbidity and more rapid return to daily activities. Morcellation is the fragmentation of a large mass into smaller pieces to make resection through port incisions possible. Over the last year there has been a discussion worldwide about the safety of morcellation. OBJECTIVE: The aim of our study was to identify the complication rate of power morcellation at our institution. STUDY DESIGN: We performed a retrospective chart analysis of patients undergoing laparoscopic supracervical hysterectomy with morcellation. We compared the outcomes of patients undergoing laparoscopic supracervical hysterectomy with the use of power morcellation with a control group of women who underwent laparoscopic-assisted vaginal hysterectomy without morcellation. Women who underwent hysterectomy because of suspected malignancy were excluded. RESULTS: A total of 358 patients underwent laparoscopic hysterectomy between 2004 and 2013; 186 laparoscopic supracervical hysterectomies and 172 laparoscopic-assisted vaginal hysterectomies. The main indication for laparoscopic supracervical hysterectomy was heavy menstrual bleeding and pelvic pressure or pain (94.5%). Baseline characteristics were not significantly different except for body mass index, with a mean of 25.7 in laparoscopic supracervical hysterectomy and 27.0 in laparoscopic-assisted vaginal hysterectomy. There was a significant greater uterine weight in the laparoscopic supracervical hysterectomy group (260g vs. 202g). The overall conversion rate was 5.3% (n=19), with no significant difference between the two groups and 79% of conversions being performed for strategic reasons. There was no statistical difference in intra-operative complication rate (2.1% vs. 1.2%). Pathology reports showed no unexpected malignancies. There was no statistical difference in the complication rate post-operatively (2.2% vs. 2.9%). The overall complication rate of laparoscopic supracervical hysterectomy was 4.3% (n=8). Need for reoperation after laparoscopic supracervical hysterectomy was necessary in 7 patients (3.8%), with cervical amputation being the most common type of reoperation (n=5). In the laparoscopic-assisted vaginal hysterectomy group there were significantly more adhesiolysis performed (n=4). Parasitic myomas were discovered in 1 patient two years after morcellation (0.5%). CONCLUSION: Our study showed no injuries directly related to morcellation. There were no unexpected malignancies morcellated and only one case of parasitic myomas (0.5%).