Five pathways into one profession: Fifty years of debate on differentiated nursing practice.

The persistence of multiple educational pathways into the nursing profession continues to occupy scholars internationally. In the Netherlands, various groups within the Dutch healthcare sector have tried to differentiate nursing practice on the basis of educational backgrounds for over 50 years. Proponents argue that such reforms are needed to retain bachelor-trained nurses, improve quality of care and strengthen nurses' position in the sector. Opponents have actively resisted reforms because they would mainly benefit bachelor-trained nurses and neglect practical experience and technical skills. This historical case study aims to provide insight in this apparent stalemate. Our analysis of this debate is informed by literature on institutional work and current debates within the historiography of nursing. This study contributes to a better understanding of this contemporary debate by examining a broader timeframe than is usually studied, and by highlighting nurses' roles in complex processes of change. We argue that, rather than being stuck in their professional development, different groups of nurses have forged their own path forward in their professional development, albeit via different strategies.

Association between Inappropriate End-of-Life Cancer Care and Specialist Palliative Care: A Retrospective Observational Study in Two Acute Care Hospitals.

A substantial number of patients with life-threatening illnesses like cancer receive inappropriate end-of-life care. Improving their quality of end-of-life care is a priority for patients and their families and for public health. To investigate the association between provision, timing, and initial setting of hospital-based specialist palliative care and potentially inappropriate end-of-life care for patients with cancer in two acute care hospitals in the Netherlands, we conducted a retrospective observational study using hospital administrative databases. All adults diagnosed with or treated for cancer in the year preceding their death in 2018 or 2019 were included. The main exposure was hospital-based specialist palliative care initiated >30 days before death. The outcome measures in the last 30 days of life were six quality indicators for inappropriate end-of-life care (≥2 ED-visits, ≥2 hospital admissions, >14 days hospitalization, ICU-admission, chemotherapy, hospital death). We identified 2603 deceased patients, of whom 14% (n = 359) received specialist palliative care >30 days before death (exposure group). Overall, 27% (n = 690) received potentially inappropriate end-of-life care: 19% in the exposure group, versus 28% in the non-exposure group (p < 0.001). The exposure group was 45% less likely to receive potentially inappropriate end-of-life care (AOR 0.55; 95% CI 0.41 to 0.73). Early (>90 days) and late (≤90 and >30 days) initiation of specialist palliative care, as well as outpatient and inpatient initiation, were all associated with less potentially inappropriate end-of-life care (AOR 0.49; 0.62; 0.32; 0.64, respectively). Thus, timely access to hospital-based specialist palliative care is associated with less potentially inappropriate end-of-life care for patients with cancer. The outpatient initiation of specialist palliative care seems to enhance this result.

Scrutinizing the human TEX genes in the context of human male infertility.

BACKGROUND: Infertility affects around 15% of all couples worldwide and is increasingly linked to variants in genes specifically expressed in the testis. Well-established causes of male infertility include pathogenic variants in the genes TEX11, TEX14, and TEX15, while few studies have recently reported variants in TEX13B, TEX13C, FAM9A (TEX39A), and FAM9B (TEX39B). OBJECTIVES: We aimed at screening for novel potential candidate genes among the human TEX ("testis expressed") genes as well as verifying previously described disease associations in this set of genes. MATERIALS AND METHODS: To this end, we screened the exome sequencing data of 1305 men, including 1056 crypto- and azoospermic individuals, and determined cell-specific expression by analyzing testis-specific single-cell RNA sequencing data for genes with identified variants. To investigate the overarching role in male fertility, we generated testis-specific knockdown (KD) models of all 10 orthologous TEX genes in Drosophila melanogaster. RESULTS: We detected rare potential disease-causing variants in TEX10, TEX13A, TEX13B, TEX13C, TEX13D, ZFAND3 (TEX27), TEX33, FAM9A (TEX39A), and FAM9B (TEX39B), in 28 infertile men, of which 15 men carried variants in TEX10, TEX27, and TEX33. The KD of TEX2, TEX9, TEX10, TEX13, ZFAND3 (TEX27), TEX28, TEX30, NFX1 (TEX42), TEX261, and UTP4 (TEX292) in Drosophila resulted in normal fertility. DISCUSSION: Based on our findings, the autosomal dominant predicted genes TEX10 and ZFAND3 (TEX27) and the autosomal recessive predicted gene TEX33, which all three are conceivably required for germ cell maturation, were identified as novel potential candidate genes for human non-obstructive azoospermia. We additionally identified hemizygous loss-of-function (LoF) variants in TEX13B, TEX13C, and FAM9A (TEX39A) as unlikely monogenic culprits of male infertility as LoF variants were also found in control men. CONCLUSION: Our findings concerning the X-linked genes TEX13B, TEX13C, and FAM9A (TEX39A) contradict previous reports and will decrease false-positive reports in genetic diagnostics of azoospermic men.

WWC2 expression in the testis: Implications for spermatogenesis and male fertility.

The family of WWC proteins is known to regulate cell proliferation and organ growth control via the Hippo signaling pathway. As WWC proteins share a similar domain structure and a common set of interacting proteins, they are supposed to fulfill compensatory functions in cells and tissues. While all three WWC family members WWC1, WWC2, and WWC3 are found co-expressed in most human organs including lung, brain, kidney, and liver, in the testis only WWC2 displays a relatively high expression. In this study, we investigated the testicular WWC2 expression in spermatogenesis and male fertility. We show that the Wwc2 mRNA expression level in mouse testes is increased during development in parallel with germ cell proliferation and differentiation. The cellular expression of each individual WWC family member was evaluated in published single-cell mRNA datasets of murine and human testes demonstrating a high WWC2 expression predominantly in early spermatocytes. In line with this, immunohistochemistry revealed cytosolic WWC2 protein expression in primary spermatocytes from human testes displaying full spermatogenesis. In accordance with these findings, markedly lower WWC2 expression levels were detected in testicular tissues from mice and men lacking germ cells. Finally, analysis of whole-exome sequencing data of male patients affected by infertility and unexplained severe spermatogenic failure revealed several heterozygous, rare WWC2 gene variants with a proposed damaging function and putative impact on WWC2 protein structure. Taken together, our findings provide novel insights into the testicular expression of WWC2 and show its cell-specific expression in spermatocytes. As rare WWC2 variants were identified in the background of disturbed spermatogenesis, WWC2 may be a novel candidate gene for male infertility.

Linking human Dead end 1 (DND1) variants to male infertility employing zebrafish embryos.

STUDY QUESTION: Is the vertebrate protein Dead end (DND1) a causative factor for human infertility and can novel in vivo assays in zebrafish help in evaluating this? SUMMARY ANSWER: Combining patient genetic data with functional in vivo assays in zebrafish reveals a possible role for DND1 in human male fertility. WHAT IS KNOWN ALREADY: About 7% of the male population is affected by infertility but linking specific gene variants to the disease is challenging. The function of the DND1 protein was shown to be critical for germ cell development in several model organisms but a reliable and cost-effective method for evaluating the activity of the protein in the context of human male infertility is still missing. STUDY DESIGN, SIZE, DURATION: Exome data from 1305 men included in the Male Reproductive Genomics cohort were examined in this study. A total of 1114 of the patients showed severely impaired spermatogenesis but were otherwise healthy. Eighty-five men with intact spermatogenesis were included in the study as controls. PARTICIPANTS/MATERIALS, SETTING, METHODS: We screened the human exome data for rare, stop-gain, frameshift, splice site, as well as missense variants in DND1. The results were validated by Sanger sequencing. Immunohistochemical techniques and, when possible, segregation analyses were performed for patients with identified DND1 variants. The amino acid exchange in the human variant was mimicked at the corresponding site of the zebrafish protein. Using different aspects of germline development in live zebrafish embryos as biological assays, we examined the activity level of these DND1 protein variants. MAIN RESULTS AND THE ROLE OF CHANCE: In human exome sequencing data, we identified four heterozygous variants in DND1 (three missense and one frameshift variant) in five unrelated patients. The function of all of the variants was examined in the zebrafish and one of those was studied in more depth in this model. We demonstrate the use of zebrafish assays as a rapid and effective biological readout for evaluating the possible impact of multiple gene variants on male fertility. This in vivo approach allowed us to assess the direct impact of the variants on germ cell function in the context of the native germline. Focusing on the DND1 gene, we find that zebrafish germ cells, expressing orthologs of DND1 variants identified in infertile men, failed to arrive correctly at the position where the gonad develops and exhibited defects in cell fate maintenance. Importantly, our analysis facilitated the evaluation of single nucleotide variants, whose impact on protein function is difficult to predict, and allowed us to distinguish variants that do not affect the protein's activity from those that strongly reduce it and could thus potentially be the primary cause for the pathological condition. These aberrations in germline development resemble the testicular phenotype of azoospermic patients. LIMITATIONS, REASONS FOR CAUTION: The pipeline we present requires access to zebrafish embryos and to basic imaging equipment. The notion that the activity of the protein in the zebrafish-based assays is relevant for the human homolog is well supported by previous knowledge. Nevertheless, the human protein may differ in some respects from its homologue in zebrafish. Thus, the assay should be considered only one of the parameters used in defining DND1 variants as causative or non-causative for infertility. WIDER IMPLICATIONS OF THE FINDINGS: Using DND1 as an example, we have shown that the approach described in this study, relying on bridging between clinical findings and fundamental cell biology, can help to establish links between novel human disease candidate genes and fertility. In particular, the power of the approach we developed is manifested by the fact that it allows the identification of DND1 variants that arose de novo. The strategy presented here can be applied to different genes in other disease contexts. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the German Research Foundation, Clinical Research Unit, CRU326 'Male Germ Cells'. There are no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Functional assessment of DMRT1 variants and their pathogenicity for isolated male infertility.

OBJECTIVE: To study the impact of Doublesex and mab-3-related transcription factor 1 (DMRT1) gene variants on the encoded protein's function and the variants' pathogenic relevance for isolated male infertility caused by azoospermia. DESIGN: This study established a novel luciferase assay for DMRT1 missense variants using 2 different target promotors and validated the assay by analyzing previously published variants associated with differences in sex development. SETTING: University genetics research institute and tertiary referral center for couples' infertility. PATIENT(S): Eleven infertile men with severely impaired spermatogenesis resulting in crypto- or azoospermia and carrying rare heterozygous missense variants in DMRT1 were identified within the Male Reproductive Genomics study. MAIN OUTCOME MEASURE(S): Luciferase assays with human DMRT1 variants to test functional effects on the CYP19A1 and Stra8 target promoters. RESULT(S): We first developed and refined luciferase assays to reliably test the functional impact of DMRT1 missense variants. Next, the assay was validated by analyzing 2 DMRT1 variants associated with differences in sex development, of which c.240G>C p.(Arg80Ser) displayed highly significant effects on both target promoters compared with the wild-type protein (-40% and +100%, respectively) and c.331A>G p.(Arg111Gly) had a significant effect on the Stra8 promoter (-76%). We then systematically characterized 11 DMRT1 variants identified in infertile men. The de novo variant c.344T>A p.(Met115Lys) showed a pronounced loss of function in both DMRT1 target promoters (-100% and -86%, respectively). Variants c.308A>G p.(Lys103Arg) and c.991G>C p.(Asp331His) showed a significant gain of function exclusively for the CYP19A1 promoter (+15% and +19%, respectively). Based on these results, 3 variants were reclassified according to clinical guidelines. CONCLUSION(S): The present study highlights the importance of functionally characterizing DMRT1 variants of uncertain clinical significance. Using luciferase assays for diagnostic purposes enables an improved causal diagnosis for isolated male infertility.

Diverse monogenic subforms of human spermatogenic failure.

Non-obstructive azoospermia (NOA) is the most severe form of male infertility and typically incurable. Defining the genetic basis of NOA has proven challenging, and the most advanced classification of NOA subforms is not based on genetics, but simple description of testis histology. In this study, we exome-sequenced over 1000 clinically diagnosed NOA cases and identified a plausible recessive Mendelian cause in 20%. We find further support for 21 genes in a 2-stage burden test with 2072 cases and 11,587 fertile controls. The disrupted genes are primarily on the autosomes, enriched for undescribed human "knockouts", and, for the most part, have yet to be linked to a Mendelian trait. Integration with single-cell RNA sequencing data shows that azoospermia genes can be grouped into molecular subforms with synchronized expression patterns, and analogs of these subforms exist in mice. This analysis framework identifies groups of genes with known roles in spermatogenesis but also reveals unrecognized subforms, such as a set of genes expressed across mitotic divisions of differentiating spermatogonia. Our findings highlight NOA as an understudied Mendelian disorder and provide a conceptual structure for organizing the complex genetics of male infertility, which may provide a rational basis for disease classification.

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.

Phasing of de novo mutations using a scaled-up multiple amplicon long-read sequencing approach.

De novo mutations (DNMs) play an important role in severe genetic disorders that reduce fitness. To better understand their role in disease, it is important to determine the parent-of-origin and timing of mutational events that give rise to these mutations, especially in sex-specific developmental disorders such as male infertility. However, currently available short-read sequencing approaches are not ideally suited for phasing, as this requires long continuous DNA strands that span both the DNM and one or more informative single-nucleotide polymorphisms. To overcome these challenges, we optimized and implemented a multiplexed long-read sequencing approach using Oxford Nanopore technologies MinION platform. We focused on improving target amplification, integrating long-read sequenced data with high-quality short-read sequence data, and developing an anchored phasing computational method. This approach handled the inherent phasing challenges of long-range target amplification and the normal accumulation of sequencing error associated with long-read sequencing. In total, 77 of 109 DNMs (71%) were successfully phased and parent-of-origin identified. The majority of phased DNMs were prezygotic (90%), the accuracy of which is highlighted by an average mutant allele frequency of 49.6% and standard error of 0.84%. This study demonstrates the benefits of employing an integrated short-read and long-read sequencing approach for large-scale DNM phasing.

Large-scale analyses of the X chromosome in 2,354 infertile men discover recurrently affected genes associated with spermatogenic failure.

Although the evolutionary history of the X chromosome indicates its specialization in male fitness, its role in spermatogenesis has largely been unexplored. Currently only three X chromosome genes are considered of moderate-definitive diagnostic value. We aimed to provide a comprehensive analysis of all X chromosome-linked protein-coding genes in 2,354 azoospermic/cryptozoospermic men from four independent cohorts. Genomic data were analyzed and compared with data in normozoospermic control individuals and gnomAD. While updating the clinical significance of known genes, we propose 21 recurrently mutated genes strongly associated with and 34 moderately associated with azoospermia/cryptozoospermia not previously linked to male infertility (novel). The most frequently affected prioritized gene, RBBP7, was found mutated in ten men across all cohorts, and our functional studies in Drosophila support its role in germ stem cell maintenance. Collectively, our study represents a significant step towards the definition of the missing genetic etiology in idiopathic severe spermatogenic failure and significantly reduces the knowledge gap of X-linked genetic causes of azoospermia/cryptozoospermia contributing to the development of future diagnostic gene panels.

Evaluating quality of care at the end of life and setting best practice performance standards: a population-based observational study using linked routinely collected administrative databases.

BACKGROUND: A high percentage of people dying at home, and a low percentage of people being admitted to hospital and dying there are regarded as indicators of appropriate care at the end of life. However, performance standards for these quality indicators are often lacking, which makes it difficult to state whether an indicator score falls between the ranges of good or poor quality care. The aim of this study was to assess quality indicators concerning place of death and hospital care utilization in people with diseases relevant for palliative care, and to establish best practice performance standards based on indicator scores in 31 regions in the Netherlands. METHODS: A retrospective nationwide population-based observational study was conducted, using routinely collected administrative data concerning persons who died in 2017 in the Netherlands with underlying causes relevant for palliative care (N = 109,707). Data from four registries were linked for analysis. Scores on eight quality indicators concerning place of death and hospital care utilization were calculated, and compared across 31 healthcare insurance regions to establish relative benchmarks. RESULTS: On average, 36.4% of the study population died at home (range between regions 30.5%-42.6%) and 20.4% in hospital (range 16.6%-25.5%). Roughly half of the population who received hospital care at any time in the last year of life were found to (also) receive hospital care in the last month of life. In the last month, 32.0% of the study population were admitted to hospital (range 29.4-36.4%), 5.3% to an Intensive Care Unit (range 3.2-6.9%) and 23.9% visited an Emergency Department (range 21.0-27.4%). In the same time period, less than 1% of the study population was resuscitated in hospital or received tube or intravenous feeding in hospital. CONCLUSIONS: The variation between regions points towards opportunities for practice improvement. The best practice performance standards as set in this study serve as ambitious but attainable targets for those regions that currently do not meet the standards. Policymakers, healthcare providers and researchers can use the suggested performance standards to further analyze causes of variance between regions and develop and test interventions that can improve practice.

Development of a national quality framework for palliative care in a mixed generalist and specialist care model: A whole-sector approach and a modified Delphi technique.

In a predominantly biomedical healthcare model focused on cure, providing optimal, person-centred palliative care is challenging. The general public, patients, and healthcare professionals are often unaware of palliative care's benefits. Poor interdisciplinary teamwork and limited communication combined with a lack of early identification of patients with palliative care needs contribute to sub-optimal palliative care provision. We aimed to develop a national quality framework to improve availability and access to high-quality palliative care in a mixed generalist-specialist palliative care model. We hypothesised that a whole-sector approach and a modified Delphi technique would be suitable to reach this aim. Analogous to the international AGREE guideline criteria and employing a whole-sector approach, an expert panel comprising mandated representatives for patients and their families, various healthcare associations, and health insurers answered the main question: 'What are the elements defining high-quality palliative care in the Netherlands?'. For constructing the quality framework, a bottleneck analysis of palliative care provision and a literature review were conducted. Six core documents were used in a modified Delphi technique to build the framework with the expert panel, while stakeholder organisations were involved and informed in round-table discussions. In the entire process, preparing and building relationships took one year and surveying, convening, discussing content, consulting peers, and obtaining final consent from all stakeholders took 18 months. A quality framework, including a glossary of terms, endorsed by organisations representing patients and their families, general practitioners, elderly care physicians, medical specialists, nurses, social workers, psychologists, spiritual caregivers, and health insurers was developed and annexed with a summary for patients and families. We successfully developed a national consensus-based patient-centred quality framework for high-quality palliative care in a mixed generalist-specialist palliative care model. A whole-sector approach and a modified Delphi technique are feasible structures to achieve this aim. The process we reported may guide other countries in their initiatives to enhance palliative care.

Inappropriate end-of-life cancer care in a generalist and specialist palliative care model: a nationwide retrospective population-based observational study.

OBJECTIVES: To evaluate the impact of provision and timing of palliative care (PC) on potentially inappropriate end-of-life care to patients with cancer in a mixed generalist-specialist PC model. METHOD: A retrospective population-based observational study using a national administrative health insurance database. All 43 067 adults in the Netherlands, who were diagnosed with or treated for cancer during the year preceding their death in 2017, were included. Main exposure was either generalist or specialist PC initiated >30 days before death (n=16 967). Outcomes were measured over the last 30 days of life, using quality indicators for potentially inappropriate end-of-life care. RESULTS: In total, 14 504 patients (34%) experienced potentially inappropriate end-of-life care; 2732 were provided with PC >30 days before death (exposure group) and 11 772 received no PC or ≤30 days before death (non-exposure group) (16% vs 45%, p<0.001). Most patients received generalist PC (88%). Patients provided with PC >30 days before death were 5 times less likely to experience potentially inappropriate end-of-life care (adjusted OR (AOR) 0.20; (95% CI 0.15 to 0.26)) than those with no PC or PC in the last 30 days. Both early (>90 days) and late (>30 and≤90 days) PC initiation had lower odds for potentially inappropriate end-of-life care (AOR 0.23 and 0.19, respectively). CONCLUSION: Timely access to PC in a mixed generalist-specialist PC model significantly decreases the likelihood of potentially inappropriate end-of-life care for patients with cancer. Generalist PC can play a substantial role.

What are the historical roots of the COVID-19 infodemic? Lessons from the past

This scoping review explores the history of the term infodemic and its usefulness as a tool for public health policy-making. It presents the information-related problems the term has encompassed; historical research on these problems, which predate the term itself; and in-depth analyses of their iterations in three historical outbreaks with long-term significance for public health policy: the 1918 influenza pandemic, the beginning of the HIV/AIDS pandemic in the 1980s, and the 2003 outbreak of severe acute respiratory syndrome. Particular attention is paid to the characteristics of scientific practice that inadvertently contributed to the generation of misinformation, as well as other factors that played a role: historical legacies, persistent inequalities and a growing distrust of scientific authority. Historical perspective helps balance contemporary analyses of infodemics that focus too narrowly on the role of new social media in disseminating misinformation and disinformation. Insights derived from the historical record can also be useful to contemporary infodemic management.

A systematic review of the validated monogenic causes of human male infertility: 2020 update and a discussion of emerging gene-disease relationships.

BACKGROUND: Human male infertility has a notable genetic component, including well-established diagnoses such as Klinefelter syndrome, Y-chromosome microdeletions and monogenic causes. Approximately 4% of all infertile men are now diagnosed with a genetic cause, but a majority (60-70%) remain without a clear diagnosis and are classified as unexplained. This is likely in large part due to a delay in the field adopting next-generation sequencing (NGS) technologies, and the absence of clear statements from field leaders as to what constitutes a validated cause of human male infertility (the current paper aims to address this). Fortunately, there has been a significant increase in the number of male infertility NGS studies. These have revealed a considerable number of novel gene-disease relationships (GDRs), which each require stringent assessment to validate the strength of genotype-phenotype associations. To definitively assess which of these GDRs are clinically relevant, the International Male Infertility Genomics Consortium (IMIGC) has identified the need for a systematic review and a comprehensive overview of known male infertility genes and an assessment of the evidence for reported GDRs. OBJECTIVE AND RATIONALE: In 2019, the first standardised clinical validity assessment of monogenic causes of male infertility was published. Here, we provide a comprehensive update of the subsequent 1.5 years, employing the joint expertise of the IMIGC to systematically evaluate all available evidence (as of 1 July 2020) for monogenic causes of isolated or syndromic male infertility, endocrine disorders or reproductive system abnormalities affecting the male sex organs. In addition, we systematically assessed the evidence for all previously reported possible monogenic causes of male infertility, using a framework designed for a more appropriate clinical interpretation of disease genes. SEARCH METHODS: We performed a literature search according to the PRISMA guidelines up until 1 July 2020 for publications in English, using search terms related to 'male infertility' in combination with the word 'genetics' in PubMed. Next, the quality and the extent of all evidence supporting selected genes were assessed using an established and standardised scoring method. We assessed the experimental quality, patient phenotype assessment and functional evidence based on gene expression, mutant in-vitro cell and in-vivo animal model phenotypes. A final score was used to determine the clinical validity of each GDR, across the following five categories: no evidence, limited, moderate, strong or definitive. Variants were also reclassified according to the American College of Medical Genetics and Genomics-Association for Molecular Pathology (ACMG-AMP) guidelines and were recorded in spreadsheets for each GDR, which are available at imigc.org. OUTCOMES: The primary outcome of this review was an overview of all known GDRs for monogenic causes of human male infertility and their clinical validity. We identified a total of 120 genes that were moderately, strongly or definitively linked to 104 infertility phenotypes. WIDER IMPLICATIONS: Our systematic review curates all currently available evidence to reveal the strength of GDRs in male infertility. The existing guidelines for genetic testing in male infertility cases are based on studies published 25 years ago, and an update is far overdue. The identification of 104 high-probability 'human male infertility genes' is a 33% increase from the number identified in 2019. The insights generated in the current review will provide the impetus for an update of existing guidelines, will inform novel evidence-based genetic testing strategies used in clinics, and will identify gaps in our knowledge of male infertility genetics. We discuss the relevant international guidelines regarding research related to gene discovery and provide specific recommendations to the field of male infertility. Based on our findings, the IMIGC consortium recommend several updates to the genetic testing standards currently employed in the field of human male infertility, most important being the adoption of exome sequencing, or at least sequencing of the genes validated in this study, and expanding the patient groups for which genetic testing is recommended.

Variant PNLDC1, Defective piRNA Processing, and Azoospermia.

BACKGROUND: P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are short (21 to 35 nucleotides in length) and noncoding and are found almost exclusively in germ cells, where they regulate aberrant expression of transposable elements and postmeiotic gene expression. Critical to the processing of piRNAs is the protein poly(A)-specific RNase-like domain containing 1 (PNLDC1), which trims their 3' ends and, when disrupted in mice, causes azoospermia and male infertility. METHODS: We performed exome sequencing on DNA samples from 924 men who had received a diagnosis of nonobstructive azoospermia. Testicular-biopsy samples were analyzed by means of histologic and immunohistochemical tests, in situ hybridization, reverse-transcriptase-quantitative-polymerase-chain-reaction assay, and small-RNA sequencing. RESULTS: Four unrelated men of Middle Eastern descent who had nonobstructive azoospermia were found to carry mutations in PNLDC1: the first patient had a biallelic stop-gain mutation, p.R452Ter (rs200629089; minor allele frequency, 0.00004); the second, a novel biallelic missense variant, p.P84S; the third, two compound heterozygous mutations consisting of p.M259T (rs141903829; minor allele frequency, 0.0007) and p.L35PfsTer3 (rs754159168; minor allele frequency, 0.00004); and the fourth, a novel biallelic canonical splice acceptor site variant, c.607-2A→T. Testicular histologic findings consistently showed error-prone meiosis and spermatogenic arrest with round spermatids of type Sa as the most advanced population of germ cells. Gene and protein expression of PNLDC1, as well as the piRNA-processing proteins PIWIL1, PIWIL4, MYBL1, and TDRKH, were greatly diminished in cells of the testes. Furthermore, the length distribution of piRNAs and the number of pachytene piRNAs was significantly altered in men carrying PNLDC1 mutations. CONCLUSIONS: Our results suggest a direct mechanistic effect of faulty piRNA processing on meiosis and spermatogenesis in men, ultimately leading to male infertility. (Funded by Innovation Fund Denmark and others.).

TRIM71 Deficiency Causes Germ Cell Loss During Mouse Embryogenesis and Is Associated With Human Male Infertility.

Mutations affecting the germline can result in infertility or the generation of germ cell tumors (GCT), highlighting the need to identify and characterize the genes controlling germ cell development. The RNA-binding protein and E3 ubiquitin ligase TRIM71 is essential for embryogenesis, and its expression has been reported in GCT and adult mouse testes. To investigate the role of TRIM71 in mammalian germ cell embryonic development, we generated a germline-specific conditional Trim71 knockout mouse (cKO) using the early primordial germ cell (PGC) marker Nanos3 as a Cre-recombinase driver. cKO mice are infertile, with male mice displaying a Sertoli cell-only (SCO) phenotype which in humans is defined as a specific subtype of non-obstructive azoospermia characterized by the absence of germ cells in the seminiferous tubules. Infertility in male Trim71 cKO mice originates during embryogenesis, as the SCO phenotype was already apparent in neonatal mice. The in vitro differentiation of mouse embryonic stem cells (ESCs) into PGC-like cells (PGCLCs) revealed reduced numbers of PGCLCs in Trim71-deficient cells. Furthermore, TCam-2 cells, a human GCT-derived seminoma cell line which was used as an in vitro model for PGCs, showed proliferation defects upon TRIM71 knockdown. Additionally, in vitro growth competition assays, as well as proliferation assays with wild type and CRISPR/Cas9-generated TRIM71 mutant NCCIT cells showed that TRIM71 also promotes proliferation in this malignant GCT-derived non-seminoma cell line. Importantly, the PGC-specific markers BLIMP1 and NANOS3 were consistently downregulated in Trim71 KO PGCLCs, TRIM71 knockdown TCam-2 cells and TRIM71 mutant NCCIT cells. These data collectively support a role for TRIM71 in PGC development. Last, via exome sequencing analysis, we identified several TRIM71 variants in a cohort of infertile men, including a loss-of-function variant in a patient with an SCO phenotype. Altogether, our work reveals for the first time an association of TRIM71 deficiency with human male infertility, and uncovers further developmental roles for TRIM71 in the germline during mouse embryogenesis.

Programmed Cell Death 2-Like (Pdcd2l) Is Required for Mouse Embryonic Development.

Globozoospermia is a rare form of male infertility where men produce round-headed sperm that are incapable of fertilizing an oocyte naturally. In a previous study where we undertook a whole exome screen to define novel genetic causes of globozoospermia, we identified homozygous mutations in the gene PDCD2L Two brothers carried a p.(Leu225Val) variant predicted to introduce a novel splice donor site, thus presenting PDCD2L as a potential regulator of male fertility. In this study, we generated a Pdcd2l knockout mouse to test its role in male fertility. Contrary to the phenotype predicted from its testis-enriched expression pattern, Pdcd2l null mice died during embryogenesis. Specifically, we identified that Pdcd2l is essential for post-implantation embryonic development. Pdcd2l-/- embryos were resorbed at embryonic days 12.5-17.5 and no knockout pups were born, while adult heterozygous Pdcd2l males had comparable fertility to wildtype males. To specifically investigate the role of PDCD2L in germ cells, we employed Drosophila melanogaster as a model system. Consistent with the mouse data, global knockdown of trus, the fly ortholog of PDCD2L, resulted in lethality in flies at the third instar larval stage. However, germ cell-specific knockdown with two germ cell drivers did not affect male fertility. Collectively, these data suggest that PDCD2L is not essential for male fertility. By contrast, our results demonstrate an evolutionarily conserved role of PDCD2L in development.

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.

Olanzapine Versus Haloperidol for Treatment of Delirium in Patients with Advanced Cancer: A Phase III Randomized Clinical Trial.

BACKGROUND: Treatment of delirium often includes haloperidol. Second-generation antipsychotics like olanzapine have emerged as an alternative with possibly fewer side effects. The aim of this multicenter, phase III, randomized clinical trial was to compare the efficacy and tolerability of olanzapine with haloperidol for the treatment of delirium in hospitalized patients with advanced cancer. MATERIALS AND METHODS: Eligible adult patients (≥18 years) with advanced cancer and delirium (Delirium Rating Scale-Revised-98 [DRS-R-98] total score ≥17.75) were randomized 1:1 to receive either haloperidol or olanzapine (age-adjusted, titratable doses). Primary endpoint was delirium response rate (DRR), defined as number of patients with DRS-R-98 severity score <15.25 and ≥4.5 points reduction. Secondary endpoints included time to response (TTR), tolerability, and delirium-related distress. RESULTS: Between January 2011 and June 2016, 98 patients were included in the intention-to-treat analysis. DRR was 45% (95% confidence interval [CI], 31-59) for olanzapine and 57% (95% CI, 43-71) for haloperidol (Δ DRR -12%; odds ratio [OR], 0.61; 95% CI, 0.2-1.4; p = .23). Mean TTR was 4.5 days (95% CI, 3.2-5.9 days) for olanzapine and 2.8 days (95% CI, 1.9-3.7 days; p = .18) for haloperidol. Grade ≥3 treatment-related adverse events occurred in 5 patients (10.2%) and 10 patients (20.4%) in the olanzapine and haloperidol arm, respectively. Distress rates were similar in both groups. The study was terminated early because of futility. CONCLUSION: Delirium treatment with olanzapine in hospitalized patients with advanced cancer did not result in improvement of DRR or TTR compared with haloperidol. Clinical trial identification number. NCT01539733. Dutch Trial Register. NTR2559. IMPLICATIONS FOR PRACTICE: Guidelines recommend that pharmacological interventions for delirium treatment in adults with cancer should be limited to patients who have distressing delirium symptoms. It was suggested that atypical antipsychotics, such as olanzapine, outperform haloperidol in efficacy and safety. However, collective data comparing the efficacy and safety of typical versus atypical antipsychotics in patients with cancer are limited. If targeted and judicious use of antipsychotics is considered for the treatment of delirium in patients with advanced cancer, this study demonstrated that there was no statistically significant difference in response to haloperidol or olanzapine. Olanzapine showed an overall better safety profile compared with haloperidol, although this difference was not statistically significant.