STUDY QUESTION:Which clinical definition of oocyte, zygote, and embryo maturation arrest (OZEMA) merits genetic investigation? SUMMARY ANSWER:The diagnosis OZEMA is considered when: only two mature oocytes are obtained from six cumulus-oocyte complexes (COCs), only one zygote is obtained from six metaphase II oocytes (MIIs), or no blastocysts are obtained from six two-pronuclei zygotes (2PNs). WHAT IS KNOWN ALREADY:OZEMA is a cover term for various defects, including oocyte abnormalities, fertilization failure, cleavage arrest, and abnormal embryo development, often associated with specific genetic variants. While some variants in specific genes are associated with distinct phenotypes, others commonly display variable expressivity across cycles and patients. Currently, there are no standardized cut-off values defining the OZEMA disorder. STUDY DESIGN, SIZE, DURATION:This is a pooled secondary analysis of aggregated data extracted from published studies. A PubMed search was conducted to identify peer-reviewed original studies in the human reporting genetically confirmed cases of OZEMA. Studies were included if patients had displayed OZEMA in at least two medically assisted reproduction (MAR) cycles. In total, clinical and genetic data were extracted from 132 publications, including 521 patients and 39 genes. PARTICIPANTS/MATERIALS, SETTING, METHODS:Clinical phenotypes from 132 publications were classified into oocyte maturation arrest (OMA), zona pellucida abnormality (ZPA), fertilization failure (FF), zygote arrest (ZA), early embryo arrest (EEA), mixed phenotypes, and other abnormalities. Data at both cycle and patient levels were evaluated using ratios corresponding to key developmental milestones (ratio of MII/COC, 2PN/MII, cleaved embryos/2PN, blastocysts/2PN). These ratios were compared with the expected values Vienna Consensus binomial modeling to assess whether the observed proportions were significantly lower than the established competency thresholds (P < 0.05). MAIN RESULTS AND THE ROLE OF CHANCE:This review identified 39 OZEMA-associated genes. Analysis of 668 cycles from 253 patients carrying variants in 35 genes showed abnormal developmental outcomes in 93%, based on binomial modeling. Reliable diagnosis of OZEMA requires a sufficient number of COCs, MIIs, or 2PNs to distinguish true developmental impairment from normal biological variation. When these minimal thresholds are not reached, statistical power is insufficient to reliably confirm developmental arrest. Based on our findings, OZEMA is diagnosed when only two or fewer mature oocytes form from six COCs, one or no zygote forms from six MIIs, or no blastocysts form from six 2PNs. LIMITATIONS, REASONS FOR CAUTION:This study is limited by its retrospective design and reliance exclusively on published data from women selected for poor IVF outcomes and the presence of variants in candidate OZEMA genes, which may introduce publication bias and reporting heterogeneity. Therefore, this study does not report on genetic yield from women with normal IVF outcomes. Variability in clinical protocols and genetic testing methods, limited ancestral diversity, and missing data across studies could contribute to confounding factors. WIDER IMPLICATIONS OF THE FINDINGS:This study is an important step toward understanding the clinical and genetic spectrum of OZEMA, highlighting the variability of and overlap between affected subphenotypes. Establishing cut-off values against consensus oocyte and embryo developmental competency levels provides a benchmark for more accurate classification. Importantly, this represents the most comprehensive analysis of published OZEMA cases with genetic variants to date, strengthening the reliability of the proposed clinical thresholds. These findings may guide personalized treatment strategies and genetic counseling, ultimately improving outcomes in MAR. STUDY FUNDING/COMPETING INTEREST(S):No funding was received for this study. The authors declare no competing interests. REGISTRATION NUMBER:Not applicable.

To explore genetic basis leading to meiotic disruption in human gametogenesis via exome sequencing. This study included three consanguineous families with well-defined infertility phenotypes. Exome sequencing was performed for the index case in family 1 and for the trio (index with parents) in the other two families. Sanger sequencing was used for confirmation and family segregation analysis. Exome sequencing revealed homozygous loss-of-function variations in SPIDR, TOP6BL, and RAD51AP2 in families 1, 2, and 3, respectively. Segregation in individual families revealed that the parents were carriers, as were the fertile siblings in families 1 and 2. All three genes function in double-strand break formation or repair, identified variants may therefore impair, potentially preventing its completion and contributing to infertility in the index cases. Gene-disease relationships (GDR) were re-evaluated due to the addition of new patients and/or variants in the literature. Our findings provide additional evidence for the role of SPIDR, TOP6BL, and RAD51AP2 as genetic contributors to human infertility due to meiotic errors. For patients with a similar phenotype, genetic screening could be recommended, and the identification of pathogenic variations might help avoid unsuccessful fertility treatments. Additionally, in patients with molecular defects in DNA repair genes, chromosomal instability may increase the risk of cancer; therefore, long-term follow-up by a multidisciplinary team is recommended.

Genetic diagnosis is increasingly crucial in medically assisted reproduction (MAR), enabling identification of infertility causes and guiding personalized treatments. This study investigates the genetic basis of empty follicle syndrome (EFS) in two independent consanguineous Algerian families with primary infertility. Exome sequencing and in silico analysis of a comprehensive infertility gene panel were performed on two index cases. Variants were prioritized based on gene-disease relationships. The identified ZP1 variant was further analyzed by 3D protein modeling. A literature review was conducted in order to compare genotype–phenotype correlations for ZP1, ZP2, ZP3, and ZP4 variants. Both patients and two affected siblings harbored a homozygous ZP1 c.1097G > A p.(Arg366Gln) variant inherited from both heterozygous parents. This previously described variant appears to be recurrent in North African populations. Structural modeling supported its pathogenic effect, as it likely disrupts zona pellucida structure, essential for oocyte protection and fertilization. Literature review showed that phenotypes varied among reported ZP1 mutations, ranging from complete EFS to cases with successful pregnancies. Comparative analysis of ZP2, ZP3, and ZP4 variants highlighted their critical but distinct roles in oocyte biology. The recurrent ZP1 c.1097G > A p.(Arg366Gln) variant contributes to EFS in consanguineous North African families. Genetic diagnosis using targeted gene panels is valuable for personalized infertility care and counseling. Further research into genotype–phenotype relationships and therapeutic approaches is needed to improve management of ZP-related infertility.

Study question : Do variants in HSP90AA1 cause human male infertility? Summary answer: Variants in HSP90AA1 appear as a possible autosomal dominant cause of human male infertility. What is known already : Male infertility is a highly heterogeneous condition, with so far over 300 genes described in this context. HSP90AA1 appears as a promising candidate gene for human male infertility, because the gene is highly conserved between species and knock-out of Hsp90aa1 in mice results in male-specific infertility due to azoospermia without further health implications. Study design, size, duration : We screened >2,500 infertile men for possibly pathogenic variants in HSP90AA1 and created a mouse line harbouring the homozygous missense variant c.605G>A p.(Arg202Lys). Participants/ materials, setting, methods : Phenotypes of men with identified variants were determined based on semen analysis and testicular histology. Pathogenicity of detected variants was assessed using AlphaMissense and a mouse model. Male fertility of the mutant mouse line was analysed via plug-matings, histology and immunofluorescence staining (IF). Expression of HSP90AA1 in testicular tissue was assessed by IF. Main results and the role of chance : The mode of inheritance (MOI) in mice is autosomal recessive but the constraint metrics (oe-score = 0.2, pLI = 1) and in silico prediction suggest that HSP90AA1 is an autosomal dominant gene in humans. We therefore screened for both, heterozygous and biallelic variants in exome sequencing data of infertile men. While we did not detect any biallelic loss-of-function variants, we identified the homozygous missense variant c.605G>A p.(Arg202Lys) in an azoospermic man as a promising variant. This variant is extremely rare and affects a highly conserved amino acid. However, male homozygous mice with this variant are fertile with no differences in litter size and testicular size or histology, making it unlikely that this variant is the cause of the man′s azoospermia. We therefore focused on heterozygous possibly pathogenic variants in HSP90AA1 and found a heterozygous frameshift variant in an azoospermic man with hypospermatogenesis as well as four heterozygous missense variants, predicted to affect protein function in azoo- or cryptozoospermic men. Large scale data : N/A Limitations, reasons for caution : Our findings suggest a dominant MOI but currently cannot fully prove this. To further clarify the MOI and ultimately improve clinical validity of HSP90AA1 replication of our findings in independent cohorts of infertile men as well as segregation analyses are required. Wider implications of the findings : While most human male infertility genes follow an autosomal recessive MOI, HSP90AA1 might be one of the few autosomal dominant infertility genes in humans. Differences in the MOI between humans and mice are also known from well-established infertility genes such as DMRT1 . Study funding/ competing interest(s) : This work was supported by a German Research Foundation (DFG) fellowship (award WY 215/1-1 to MJW), the DFG-sponsored Clinical Research Unit ′Male Germ Cells′ (CRU326, project 329621271 to FT), and Wellcome Trust funding (225237 to DOC). This work was supported by funding for the Wellcome Discovery Research Platform for Hidden Cell Biology (226791). ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by a German Research Foundation (DFG) fellowship (award WY 215/1-1 to MJW), the DFG-sponsored Clinical Research Unit Male Germ Cells (CRU326, project 329621271 to FT), and Wellcome Trust funding (225237 to DOC). This work was supported by funding for the Wellcome Discovery Research Platform for Hidden Cell Biology (226791). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study protocol was approved by the respective local ethics committees: MERGE cohort Muenster (2010-578-f-S) and Giessen (26/11); Strasbourg (CPP 09/40 WAC 2008-438 1W DC 200 9I 002), and Yeni Yuzyıl University, Scientific, social and noninterventional health sciences research ethics committee, Istanbul, Turkey (approval no: 2019/08). All persons gave written consent compliant with local requirements and all experiments were performed in accordance with the criteria set by the Declaration of Helsinki. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors.

STUDY QUESTION:Which research topics in the area of infertility should be prioritized in the allocation of research resources? SUMMARY ANSWER:Twelve research priorities were formulated, spanning the following areas: preventing infertility and preserving fertility, gynaecological diseases, male infertility, optimizing fertility treatments, optimizing psychosocial support and deepening knowledge on preimplantation development and early pregnancy. WHAT IS KNOWN ALREADY:Many research gaps related to infertility and its management remain understudied and underfunded, making it important to set priorities to ensure appropriate allocation of research resources. STUDY DESIGN, SIZE, DURATION:The European Society of Human Reproduction and Embryology (ESHRE) appointed a multidisciplinary working group, including a patient representative, to develop a list of research priorities related to infertility, which are relevant to researchers and institutions that fund research. PARTICIPANTS/MATERIALS, SETTING, METHODS:A list of research topics was collated based on the recommendations for future research formulated in ESHRE's evidence-based guidelines and suggestions submitted by ESHRE's Special Interest Groups as call topics for the ESHRE research grants. A scoring tool was developed to assess the expected impact of research on each topic on individuals, society and scientific advancement. Topics were scored independently by the working group members and the 12 topics with the highest scores were selected for presentation in this paper. MAIN RESULTS AND THE ROLE OF CHANCE:Using our newly developed scoring tool, we have identified 12 research priorities that broadly fall under six areas. These are preventing infertility and preserving fertility, gynaecological diseases, male infertility, optimizing fertility treatments (two priorities per area selected), optimizing psychosocial support (one priority selected) and deepening knowledge on preimplantation development and early pregnancy (three priorities selected). LIMITATIONS, REASONS FOR CAUTION:The impact scoring tool would benefit from further testing and refinement in future projects. The scoring of some impact indicators is heavily based on the judgment and expertise of the scorers, which was accounted for by ensuring representation of knowledge and experience from all relevant disciplines and subject areas as well as the patient perspective within the working group. WIDER IMPLICATIONS OF THE FINDINGS:This paper may serve to stimulate further thought and discussion within the infertility research community on the potential impact of proposed and ongoing research. It will furthermore inform and encourage policy makers involved in research funding allocation and contribute to a more efficient and purposeful allocation of research resources towards infertility research. STUDY FUNDING/COMPETING INTEREST(S):The technical support for this project was provided by ESHRE. A.C. reports employment at Juno Genetics. Y.C. reports a grant from Guerbet and honoraria from Ferring, Merck, Abbot, Nordic Pharma and Organon. G.C. reports consulting fees from Gedeon Richter and honoraria from Cooper Surgical. S.G. reports the development of www.myjourney.pt licensed under a CC BY-NC-SA 4.0 licence. J.K.-B. reports grants from the NIHR Evaluation and Studies Coordinating Centre, the Gates Foundation, the Economic and Social Research Council, BAYER Consumer Health and MRC Confidence in Concept; honoraria from Ferring and Cooper Surgical; travel support from Ferring, Cooper Surgical, Congressworks LLP, Deutsche Gesellschaft für Andrologie e. V., BAYER, University of Munster and ESHRE; a patent for microchannel sperm cell preparation; and a leadership or fiduciary role in the Association of Clinical and Reproductive Scientists. A.P. reports grants (to her institution) and consulting fees from Gedeon Richter, Ferring, Merck A/S and Cryos; honoraria from Gedeon Richter, Ferring, Merck A/S and Organon; and travel support (to her institution) from Gedeon Richter. H.S.N. reports grants from Freya Biosciences ApS, Ferring Pharmaceuticals, BioInnovation Institute, Ministry of Education, Novo Nordic Foundation, Augustinus Fonden, Oda og Hans Svenningsens Fond, Demant Fonden, Ole Kirks Fond and the Independent Research Fund Denmark; speaker's fees from Ferring, Merck A/S, Astra Zeneca, Cook Medical, Gedeon Richter, Ibsa Nordic, Novo Nordisk A/S; co-development of an app with the Maternity Foundation; and co-founding a project with Lulu Health. The remaining authors (J.T., A.A., I.D., C.F., M.G., A.S.L., M.M.-R., V.N., A.O., N.R., M.S.-L., P.T., N.V., S.V. and K.S.) have nothing to declare. TRIAL REGISTRATION NUMBER:N/A.

In recent years, an increasing number of genes associated with male and female infertility have been identified. The genetics of infertility is no longer limited to the analysis of karyotypes or specific genes, and it is now possible to analyse several dozen infertility genes simultaneously. Here, we present the diagnostic activity over the past two years including 140 patients (63 women and 77 men). Targeted sequencing revealed causative variants in 17 patients, representing an overall diagnostic rate of 12.1%, with prevalence rates in females and males of 11% and 13%, respectively. The gene-disease relationship (GDR) was re-evaluated for genes due to the addition of new patients and/or variants in the actual study. Five genes changed categories: two female genes (MEIOB and TBPL2) moved from limited to moderate; two male genes (SOHLH1 and GALNTL5) moved from no evidence to strong and from limited to moderate; and SEPTIN12, which was unable to classify male infertility, was reclassified as limited. Many infertility genes have yet to be identified. With the increasing integration of genetics in reproductive medicine, the scope of intervention extends to include other family members, in addition to individual patients or couples. Genetic counselling consultations and appropriate staffing will need to be established in fertility centres. Trial registration number: Not applicable.

BACKGROUND The genetic composition of embryos generated by in vitro fertilization (IVF) can be examined with preimplantation genetic testing (PGT). Until recently, PGT was limited to detecting single-gene, high-risk pathogenic variants, large structural variants, and aneuploidy. Recent advances have made genome-wide genotyping of IVF embryos feasible and affordable, raising the possibility of screening embryos for their risk of polygenic diseases such as breast cancer, hypertension, diabetes, or schizophrenia. Despite a heated debate around this new technology, called polygenic embryo screening (PES; also PGT-P), it is already available to IVF patients in some countries. Several articles have studied epidemiological, clinical, and ethical perspectives on PES; however, a comprehensive, principled review of this emerging field is missing.OBJECTIVE AND RATIONALE This review has four main goals. First, given the interdisciplinary nature of PES studies, we aim to provide a self-contained educational background about PES to reproductive specialists interested in the subject. Second, we provide a comprehensive and critical review of arguments for and against the introduction of PES, crystallizing and prioritizing the key issues. We also cover the attitudes of IVF patients, clinicians, and the public towards PES. Third, we distinguish between possible future groups of PES patients, highlighting the benefits and harms pertaining to each group. Finally, our review, which is supported by ESHRE, is intended to aid healthcare professionals and policymakers in decision-making regarding whether to introduce PES in the clinic, and if so, how, and to whom.SEARCH METHODS We searched for PubMed-indexed articles published between 1/1/2003 and 1/3/2024 using the terms 'polygenic embryo screening', 'polygenic preimplantation', and 'PGT-P'. We limited the review to primary research papers in English whose main focus was PES for medical conditions. We also included papers that did not appear in the search but were deemed relevant.OUTCOMES The main theoretical benefit of PES is a reduction in lifetime polygenic disease risk for children born after screening. The magnitude of the risk reduction has been predicted based on statistical modelling, simulations, and sibling pair analyses. Results based on all methods suggest that under the best-case scenario, large relative risk reductions are possible for one or more diseases. However, as these models abstract several practical limitations, the realized benefits may be smaller, particularly due to a limited number of embryos and unclear future accuracy of the risk estimates. PES may negatively impact patients and their future children, as well as society. The main personal harms are an unindicated IVF treatment, a possible reduction in IVF success rates, and patient confusion, incomplete counselling, and choice overload. The main possible societal harms include discarded embryos, an increasing demand for 'designer babies', overemphasis of the genetic determinants of disease, unequal access, and lower utility in people of non-European ancestries. Benefits and harms will vary across the main potential patient groups, comprising patients already requiring IVF, fertile people with a history of a severe polygenic disease, and fertile healthy people. In the United States, the attitudes of IVF patients and the public towards PES seem positive, while healthcare professionals are cautious, sceptical about clinical utility, and concerned about patient counselling. WIDER IMPLICATIONS The theoretical potential of PES to reduce risk across multiple polygenic diseases requires further research into its benefits and harms. Given the large number of practical limitations and possible harms, particularly unnecessary IVF treatments and discarded viable embryos, PES should be offered only within a research context before further clarity is achieved regarding its balance of benefits and harms. The gap in attitudes between healthcare professionals and the public needs to be narrowed by expanding public and patient education and providing resources for informative and unbiased genetic counselling. Graphical Abstract The principles, estimated benefits, personal and societal harms, and clinical considerations of prioritizing IVF embryos based on their risk for late-onset, polygenic conditions.

STUDY QUESTION What is the current practice and views on (expanded) carrier screening ((E)CS) among healthcare professionals in medically assisted reproductive (MAR) practices in Europe? SUMMARY ANSWER The findings show a limited support for ECS with less than half of the respondents affiliated to centres offering ECS, and substantial variation in practice between centres in Europe. WHAT IS KNOWN ALREADY The availability of next-generation sequencing, which enables testing for large groups of genes simultaneously, has facilitated the introduction and expansion of ECS strategies, currently offered particularly in the private sector in the context of assisted reproduction. STUDY DESIGN, SIZE, DURATION A cross-sectional survey evaluating practice and current views among professionals working in MAR practice in different European countries was designed using the online SurveyMonkey tool. The web-based questionnaire included questions on general information regarding the current practice of (E)CS in MAR and questions on what is offered, to whom the test is offered, and how it is offered. It consisted mostly of multiple-choice questions with comment boxes, but also included open questions on the respondents’ attitudes/concerns relevant to (E)CS practice, and room to upload requested files (e.g. guidelines and gene panels). In total, 338 responses were collected from 8 February 2022 to 11 April 2022. PARTICIPANTS/MATERIALS, SETTING, METHODS The online survey was launched with an invitation email from the ESHRE central office (n = 4889 emails delivered) and the European Society of Human Genetics (ESHG) central office (n = 1790 emails delivered) sent to the ESHRE and ESHG members, and by social media posts. The survey was addressed to European MAR centres or gamete banks and to centres located in non-European countries participating in the European IVF-monitoring Consortium. Two reminder emails were sent. After exclusion of 39 incomplete responses received (e.g. only background information), 299 respondents from 40 different countries were included for analyses. MAIN RESULTS AND THE ROLE OF CHANCE Overall, 42.5% (127/299) of respondents were affiliated to centres offering ECS. The perceived responsibility to enable prospective parents to make informed reproductive decisions and preventing suffering/burden for parents were the main reasons to offer ECS. A single ECS panel is offered by nearly 45% (39/87 received answers) of the centres offering ECS, 25.3% (22/87) of those centres offer a selection of ECS panels, and 29.9% (26/87) offer whole exome sequencing and a large in silico panel. Different ranges of panel sizes and conditions were included in the ECS panel(s) offered. Most of the respondents (81.8%; 72/88 received answers) indicated that the panels they offer are universal and target the entire population. Pathogenic variants (89.7%; 70/78 received answers), and to a lesser extent, likely pathogenic variants (64.1%%; 50/78 received answers), were included in the ECS report for individuals and couples undergoing MAR with their own gametes. According to 87.9% (80/91 received answers) of the respondents, patients have to pay to undergo an ECS test. Most respondents (76.2%; 61/80 received answers) reported that counselling is provided before and after the ECS test. Preimplantation genetic testing, the use of donor gametes, and prenatal diagnostic testing were the three main reproductive options discussed with identified carrier couples. The main reason, according to the respondents, for not offering ECS in their centre, was the lack of professional recommendations supporting ECS (52.5%; 73/139 received answers) and the high cost for couples or reimbursement not being available (49.6%; 69/139). The challenges and moral dilemmas encountered by the respondents revolved mainly around the content of the offer, including the variants classification and the heterogeneity of the panels, the counselling, and the cost of the test. LIMITATIONS, REASONS FOR CAUTION Although the total number of respondents was acceptable, the completion rate of the survey was suboptimal. In addition, the heterogeneity of answers to open-ended questions and the ambiguity of some of the answers, along with incomplete responses, posed a challenge in interpreting survey results. It is also plausible that some questions were not easily understood by the respondents. For this reason, response and non-response bias are acknowledged as further limitations of the survey. WIDER IMPLICATIONS OF THE FINDINGS The results of this survey could aid in identifying potential challenges or areas for improvement in the current practice of ECS in the MAR field and contribute to the discussion on how to address them. The results underline the need to stimulate a more knowledge-based debate on the complexity and the pros and cons of a possible implementation of ECS in MAR. STUDY FUNDING/COMPETING INTEREST(S) All costs relating to the development process were covered from European Society of Human Reproduction and Embryology and European Society of Human Genetics funds. There was no external funding of the development process or manuscript production. A.C. is full-time employee of Juno Genetics. L.H. declared receiving a research grant during the past 36 months from the Netherlands Organisation for Health Research and Development. She has also participated in a Health Council report of the Netherlands on preconception carrier screening and collaborated with the VSOP Dutch Genetic Alliance (patient umbrella organization on rare and genetic disorders). L.H. and C.v.E. are affiliated with Amsterdam University Medical Centre, a hospital that offers ECS in a non-commercial setting. R.V. received honoraria for presentations from Merck Academy and is unpaid board member of the executive committee of the Spanish Fertility Society. The other authors had nothing to disclose. TRIAL REGISTRATION NUMBER N/A.

piRNAs are crucial for transposon silencing, germ cell maturation, and fertility in male mice. Here, we report on the genetic landscape of piRNA dysfunction in humans and present 39 infertile men carrying biallelic variants in 14 different piRNA pathway genes, including PIWIL1, GTSF1, GPAT2, MAEL, TDRD1, and DDX4. In some affected men, the testicular phenotypes differ from those of the respective knockout mice and range from complete germ cell loss to the production of a few morphologically abnormal sperm. A reduced number of pachytene piRNAs was detected in the testicular tissue of variant carriers, demonstrating impaired piRNA biogenesis. Furthermore, LINE1 expression in spermatogonia links impaired piRNA biogenesis to transposon de-silencing and serves to classify variants as functionally relevant. These results establish the disrupted piRNA pathway as a major cause of human spermatogenic failure and provide insights into transposon silencing in human male germ cells. piRNAs are small RNA molecules found primarily in the testes of mice and men. Stallmeyer et al. demonstrate that variants in specific genes can disrupt the formation of piRNAs, impairing spermatogenesis and causing human male infertility.

Objective The ultimate treatment management of NOA involves testicular sperm extraction; however, in almost half of the men with NOA, no sperm can be retrieved. DNA defects such as double-strand breaks (DSBs) can disturb meiotic recombination and cause infertility in men due to complete early meiotic arrest. To date, few genes participating in DSB formation and/or repair have been associated with infertility in humans. However, the relationship between the failure of the meiotic DSB process and human infertility remains poorly understood. We aim to identify new genetic causes responsible for the nonobstructive azoospermia (NOA) with meiotic arrest by using exome sequencing Materials and Methods This case-control study was conducted on two Turkish consanguineous families, comprising infertile men with NOA. Testicular histopathology results showed meiotic arrest at the spermatid stage. Karyotypes were normal and no Y chromosome microdeletion was detected in the affected men. Ethical approval was obtained from the Comité de Protection de la Personne (CPP) of Strasbourg University Hospital.Saliva samples from index cases and both parents were collected after obtaining written informed consent. Exome sequencing was performed using the GenomEast Platform (IGBMC, Strasbourg, France). Detected variants were annotated and ranked by VaRank (v1.4.3). Results Exome sequencing revealed homozygous pathogenic variations in two genes namely C11orf80 (also known as TOPBBL) and RAD51AP2. The first gene is related to meiotic DNA DSB formation, while the latter is associated with DSB repair in the respective families. Meiosis could not be completed in either situation, resulting in spermatogenesis arrests at the pachytene stage of meiosis 1. Two recent reports described four NOA men from two families presenting homozygous truncating variants in C11orf80. Similarly, homozygous or compound heterozygous loss-of-function variations in RAD51AP2 were previously identified in four men diagnosed with idiopathic NOA. Since the identification of both genes were after the latest systematic review, they were neither scored norvalidated for the male infertility. The gene-disease relationship (GDR) was evaluated by including published patients and variants as well as results from the actual study. C11orf80 and RAD51AP2 were scored as 13 and 14 respectively with a classification of “strong” for both genes. Conclusion Our findings support the role of C11orf80 and RAD51AP2 as genetic contributors to human infertility by causing meiotic arrest during spermatogenesis in men. Discussion The main limitation of our study is the small number of cases included. However, it provides fresh data regarding on NOA phenotypes associated with meiotic arrest. For men with a similar phenotype, genetic screening for C11orf80 and RAD51AP2 could be recommended, and the identification of pathogenic variations might help to avoid unsuccessful testicular biopsy procedures.

Women undergoing controlled ovarian hyperstimulation prior to in vitro fertilization (IVF) are treated using various protocols to induce multiple follicular growths. Complete failure of all oocytes to mature during IVF cycles is rare; however, it is a known cause of primary female infertility. Recently, pathogenic variations in a few genes have been identified in women with oocyte maturation defects; however, the underlying genetic causes remain largely unknown. This study included a Turkish family comprising three sisters with recurring oocyte maturation arrest at the germinal vesicle stage after multiple ovarian stimulations. Exome sequencing revealed a homozygous missense variant (c.1037C>T, p.Ala346Val) in the EPAB gene (also known as PABPC1L) in all three affected sisters, which was either absent or heterozygous in the unaffected family members. Functional experiments confirming the pathogenicity of the variant were performed by transfecting HEK293T cells and demonstrated the instability and increased rate of proteolysis of the mutated PABPC1L/EPAB protein. The identified variant, located in the well-conserved fourth RNA recognition motif (RRM4), in silico 3D modelling suggested changes in the physical properties of the pathogenic variant of PABPC1L/EPAB. Our findings validate PABPC1L/EPAB as an essential genetic contributor to the oocyte maturation process in humans and have direct implications for the genetic counselling of patients and their family members.

Abstract Study question Is there a risk factor association or a monogenic relationship between FMR1 premutation and developing Fragile X-associated primary ovarian insufficiency (FXPOI)? Summary answer There is an association between FMR1 premutation and FXPOI rather than a monogenic relationship, which is highly dependent on ethnicity. What is known already Among the 40 genes involved in primary ovarian insufficiency (POI), identified in our recent systematic review (Van Der Kelen et al., 2022), the FMR1 premutation is considered as the most common cause of POI. A premutation in the FMR1 gene is defined as a CGG trinucleotide repeat length between 55 and 200 in the 5′ untranslated region. The term FXPOI is used for women with premutation in FMR1 who have a loss of normal function of the ovaries before the age of 40. There is conflicting evidence about the relationship between POI and length of premutation FMR1 alleles. Study design, size, duration Curated publications identified in PubMed and Web of Science on genetics of human female infertility and sex development by using the MESH terms, key words and inclusion/exclusion criteria described in our comprehensive systematic review were subjected to screening for “FMR1 gene.” The articles included cover a period from 1988 to the 1st of November 2021. Participants/materials, setting, methods A total of 161 publications in PubMed and 61 unique publications in Web of Science were identified, and subsequently screened for triplet expansion, primary ovarian insufficiency, and/or early menopause. Of these, 56 papers were selected, excluding publications exclusively on males as well as studies on non-human species, pediatric cases, reviews, and expression studies. The study and control groups repeat numbers, ethnicity, and conclusions in the article are listed. Main results and the role of chance Expansion in CGG trinucleotide repeat length happens at female meiosis and the risk for expansion increases with an increasing number of CGG repeats. There is an intermediate zone between 45 and 55 CGG repeats when the allele may be stable or unstable. Among 56 publications, 54 describing FMR1 triplet repeat size in women with POI, 34 were studying only the women with POI (observational) while 20 were including also control group (comparative). 2 publications were meta-analyses in which 13 and 11 case control studies were included respectively, 5 studies being in common. POI-associated premutations showed a wide range of repeat sizes. Women carrying midsize range repeats (>70-<100) potentially have a higher risk for POI compared to the general population. In recent decades, population-based screenings have indicated that FMR1 premutations are not as prevalent in women with ovarian insufficiency as previous estimates have suggested, but they still represent a substantial cause of POI. When present, the number of AGG interruptions and the size of uninterrupted CGG repeats are directly correlated with the ovarian reserve. No increased risk of POI associated with a premutation was reported among populations of non-European descent, such as the Han Chinese, Indian, and Jordan populations. Limitations, reasons for caution Available reports are difficult to compare because the ethnicity and number of patients analyzed, availability of clinical data and the quality of results are different in each study. Additionally, an effect of X-inactivation in POI women with premutation was not studied. Wider implications of the findings Owing to the low penetrance and a molecular mechanism that has not yet been fully elucidated, the clinical utility of FMR1 screening in women with reduced ovarian reserve needs further investigation before clinical implication. Trial registration number N/A

The World Health Organization (WHO) defines infertility as the inability to conceive within 12 months despite regular unprotected intercourse, a condition that concerns about 10–15% of couples globally. Infertility is considered as primary or secondary depending on whether a couple has experienced a prior pregnancy or not.

STUDY QUESTION Can the analysis of a large Turkish consanguineous family via whole exome sequencing (WES) identify novel causative genetic variation responsible for nonobstructive azoospermia (NOA) characterized by arrest at primary spermatocyte stage? SUMMARY ANSWER WES analysis revealed a homozygous nonsense variant in HORMAD1 in three affected brothers of a Turkish family. WHAT IS KNOWN ALREADY Studying patient cohorts in small or large consanguineous families using high-throughput sequencing allows the identification of genetic causes of different pathologies, including infertility. Over the last two decades, a number of genes involved in human male infertility have been discovered, but only 14 genes have been identified as being at least moderately linked to isolated NOA or oligozoospermia in men. STUDY DESIGN, SIZE, DURATION The study included a Turkish family comprising three brothers with NOA. Two brothers had a normal karyotype, normal hormonal levels and no Yq microdeletion. The testicular histopathology analysis revealed the complete arrest of spermatogenesis at the primary spermatocyte stage. PARTICIPANTS/MATERIALS, SETTING, METHODS We recruited a consanguineous Turkish family where parents were first-degree cousins and had seven children; three sons who had NOA, two sons who were fertile and two daughters for whom no information was available. Saliva samples from the index patient, his two affected brothers, parents and two nonaffected brothers (seven samples in total) were collected. Prior to WES, the index patient underwent targeted genetic testing using an infertility panel, which includes 133 infertility genes. No pathogenic variations were identified. WES was then performed on the DNA of the seven family members available. Bioinformatics analysis was performed using an in-house pipeline. Detected variants were scored and ranked, and copy number variants were called and annotated.The consequences of mutation on protein expression and localization were investigated by cell transfection followed by immunofluorescence or immunoblotting. MAIN RESULTS AND THE ROLE OF CHANCE WES revealed a homozygous nonsense variant chr1:150675797G>A; HORMAD1 (NM_032132.5): c.1021C>T, p.Gln341* in exon 13, which was confirmed in all three affected brothers. HORMAD1 encodes the HORMA domain-containing protein 1. The parents as well as the two fertile brothers were carriers of this variant. This variant may lead to the production of a truncated protein lacking the nuclear localization signal; therefore, human cells were transfected with the wild-type and mutated form, in fusion with green fluorescent protein. Immunoblotting experiments confirmed the production of a truncated HORMAD1 protein, and immunofluorescence microscopy revealed that the mutated protein displayed cytoplasmic localization while the wild type protein located to the nucleus. Altogether, our findings validate HORMAD1 as an essential genetic factor in the meiotic process in human. LIMITATIONS, REASONS FOR CAUTION According to one scoring system used to evaluate the clinical validity of male infertility genes, this study would classify HORMAD1 as displaying limited clinical evidence of being involved in male infertility. However, such a score is the maximum possible when only one family is analyzed and the addition of one patient showing a pathogenic or likely pathogenic variant would immediately change this classification to 'moderate'. Thus, this report should prompt other researchers to screen patients with NOA for this genetic variant. WIDER IMPLICATIONS OF THE FINDINGS Identification of new genetic factors involved in the human meiosis process will contribute to an improvement of our knowledge at the basic level, which in turn will allow the management of better care for infertile patients. Since Hormad1-/- knock-out female mice are also infertile, HORMAD1 could also be involved in human female infertility. Our findings have direct implications for the genetic counseling of patients and their family members. STUDY FUNDING/COMPETING INTEREST(S) The study was funded by Fondation Maladies Rares (High Throughput Sequencing and Rare Diseases-2018, 'GenOmics of rare diseases'). The authors declare that they have no conflict of interest. TRIAL REGISTRATION NUMBER N/A.

The field of reproductive genetics has undergone significant advancements with the completion of the Human Genome Project and the development of high-throughput sequencing techniques. This has led to the identification of numerous genes involved in both male and female infertility, revolutionizing the diagnosis and management of infertility patients. Genetic investigations, including karyotyping, specific genetic tests, and high-throughput sequencing, have become essential in determining the genetic causes of infertility. Moreover, the integration of genetics into reproductive medicine has expanded the scope of care to include not only affected individuals or couples but also their family members. Genetic consultations and counselling play a crucial role in identifying potentially affected relatives and offering tailored therapy and the possibility of fertility preservation. Despite the current limited therapeutic options, an increasing understanding of genotype-phenotype correlations in infertility genes holds promise for improved treatment outcomes. The availability of genetic diagnostic tools has reduced the number of idiopathic infertility cases by providing accurate aetiological diagnoses. The transition from research to clinical practice in reproductive genetics requires the establishment of genetic consultations and data warehousing systems to provide up-to-date information on gene-disease relationships. Overall, the integration of genetics into reproductive medicine has brought about a paradigm shift, emphasizing the familial dimension of infertility and offering new possibilities for personalized care and family planning.

BACKGROUND:As in other domains of medicine, high-throughput sequencing methods have led to the identification of an ever-increasing number of gene variants in the fields of both male and female infertility. The increasing number of recently identified genes allows an accurate diagnosis for previously idiopathic cases of female infertility and more appropriate patient care. However, robust evidence of the gene-disease relationships (GDR) allowing the proper translation to clinical application is still missing in many cases.OBJECTIVE AND RATIONALE:An evidence-based curation of currently identified genes involved in female infertility and differences in sex development (DSD) would significantly improve both diagnostic performance and genetic research. We therefore performed a systematic review to summarize current knowledge and assess the available GDR.SEARCH METHODS:PRISMA guidelines were applied to curate all available information from PubMed and Web of Science on genetics of human female infertility and DSD leading to infertility, from 1 January 1988 to 1 November 2021. The reviewed pathologies include non-syndromic as well as syndromic female infertility, and endocrine and reproductive system disorders. The evidence that an identified phenotype is caused by pathogenic variants in a specific gene was assessed according to a standardized scoring system. A final score (no evidence, limited, moderate, strong, or definitive) was assigned to every GDR.OUTCOMES:A total of 45 271 publications were identified and screened for inclusion of which 1078 were selected for gene and variant extraction. We have identified 395 genes and validated 466 GDRs covering all reported monogenic causes of female infertility and DSD. Furthermore, we present a genetic diagnostic flowchart including 105 genes with at least moderate evidence for female infertility and suggest recommendations for future research. The study did not take into account associated genetic risk factor(s) or oligogenic/polygenic causes of female infertility.WIDER IMPLICATIONS:We have comprehensively reviewed the existing research on the genetics of female infertility and DSD, which will enable the development of diagnostic panels using validated genes. Whole genome analysis is shifting from predominantly research to clinical application, increasing its diagnostic potential. These new diagnostic possibilities will not only decrease the number of idiopathic cases but will also render genetic counselling more effective for infertile patients and their families.

Research question: Do patients presenting with flagella ultrastructural defects as assessed by electron microscopy, and defined within three phenotypes (dysplasia of the fibrous sheath [DFS], primary flagellar dyskinesia [PFD] and non-specific flagellar abnormalities [NSFA]), have decreased chances of success in intracytoplasmic sperm injection (ICSI) or adverse obstetric and neonatal outcomes?Design: Retrospective analysis of 189 ICSI cycles from 80 men with spermatozoa flagellum ultrastructural defects (DFS [n = 16]; PFD [n = 14]; NSFA [n = 50] compared with a control group (n = 97). Cycles were cumulatively analysed. All fresh and frozen embryo transfers resulting from each ICSI attempt were included. The effect of transmission electron microscopy (TEM) phenotype on the main ICSI outcomes was assessed by a multivariate logistic regression combined with a generalized linear mixed model to account for the non-independence of the observations.Results: No predictive value of TEM phenotype was found on the main outcomes of ICSI, namely fertilization rates, pregnancy and delivery rates, and cumulative pregnancy and delivery rates. Cumulative pregnancy rates ranged from 29.0-43.3% in the different TEM phenotype subgroups compared with 36.8% in the control group. Cumulative live birth rates ranged from 24.6-36.7% compared with 31.4% in the control group. No increase was found in miscarriages, preterm births, low birth weights or birth abnormalities.Conclusions: Data on the cumulative chances of success in ICSI of patients with ultrastructural flagellar defects, a rare cause of male infertility often associated with an underlying genetic cause, are reassuring, as are obstetrical and neonatal outcomes in this population.

Les réactions d’hypersensibilité immédiate (HSI) périopératoires sont des évènements rares, mais pourvoyeurs d’une morbi-mortalité non négligeable. L’épidémiologie de ces réactions évolue avec le temps, les changements dans l’environnement et dans les pratiques professionnelles. Il est donc nécessaire de monitorer cette évolution afin d’identifier l’apparition de nouveaux risques. L’objectif de notre étude était de décrire l’épidémiologie des réactions d’HSI périopératoires en France en 2017–2018. Tout patient ayant eu une réaction d’HSI périopératoire entre le 01/01/17 et le 31/12/18 et ayant été vu en consultation d’allergologie dans un centre membre du Groupe d’étude des réactions anaphylactiques périopératoires (GERAP) était inclus. Au total, 748 patients ont été inclus, majoritairement des femmes (60 %). Parmi ces patients, 468 (63 %) avaient fait une réaction IgE-médiée et 198 (26 %) une réaction non-IgE-médiée. Huit patients (1 %) avaient une mastocytose. Les réactions d’HSI IgE-médiées étaient majoritairement sévères avec 273 (58 %) réactions de grade III selon la classification de Ring et Messmer modifiée. Les principaux agents responsables de réactions IgE-médiées étaient les curares (n = 265 ; 57 %), les antibiotiques (n = 124, 26 %) et les colorants (n = 15 ; 3 %). Seules 9 réactions (2 %) étaient attribuées au latex. Parmi les curares, le suxaméthonium était le principal agent en cause (n = 153 ; 58 %). La céfazoline était impliquée dans la moitié des réactions aux antibiotiques (n = 61, 49 %). Parmi ces patients, 10 (16 %) n’avaient jamais été anesthésiés avant. Les curares, les antibiotiques et les colorants sont les principales causes de réactions allergiques périopératoires en France en 2017–2018. Les antibiotiques occupent une place croissante dans ces réactions, notamment à cause des réactions à la céfazoline. Une attention particulière doit être portée à ce médicament, notamment pour essayer de comprendre l’origine de cette sensibilisation. L’existence d’une exposition cachée à la céfazoline dans l’environnement ou d’une réaction croisée inconnue pourrait expliquer cette sensibilisation.