Pathogenic missense variation in PABPC1L/EPAB causes female infertility due to oocyte maturation arrest at the germinal vesicle stage.

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.

Exome sequencing reveals novel causes as well as new candidate genes for human globozoospermia.

STUDY QUESTION: Can exome sequencing identify new genetic causes of globozoospermia? SUMMARY ANSWER: Exome sequencing in 15 cases of unexplained globozoospermia revealed deleterious mutations in seven new genes, of which two have been validated as causing globozoospermia when knocked out in mouse models. WHAT IS KNOWN ALREADY: Globozoospermia is a rare form of male infertility characterised by round-headed sperm and malformation of the acrosome. Although pathogenic variants in DPY19L2 and SPATA16 are known causes of globozoospermia and explain up to 70% of all cases, genetic causality remains unexplained in the remaining patients. STUDY DESIGN, SIZE, DURATION: After pre-screening 16 men for mutations in known globozoospermia genes DPY19L2 and SPATA16, exome sequencing was performed in 15 males with globozoospermia or acrosomal hypoplasia of unknown aetiology. PARTICIPANTS/MATERIALS, SETTING, METHOD: Targeted next-generation sequencing and Sanger sequencing was performed for all 16 patients to screen for single-nucleotide variants and copy number variations in DPY19L2 and SPATA16. After exclusion of one patient with DPY19L2 mutations, we performed exome sequencing for the 15 remaining subjects. We prioritised recessive and X-linked protein-altering variants with an allele frequency of <0.5% in the population database GnomAD in genes with an enhanced expression in the testis. All identified candidate variants were confirmed in patients and, where possible, in family members using Sanger sequencing. Ultrastructural examination of semen from one of the patients allowed for a precise phenotypic characterisation of abnormal spermatozoa. MAIN RESULTS AND ROLE OF CHANCE: After prioritisation and validation, we identified possibly causative variants in eight of 15 patients investigated by exome sequencing. The analysis revealed homozygous nonsense mutations in ZPBP and CCDC62 in two unrelated patients, as well as rare missense mutations in C2CD6 (also known as ALS2CR11), CCIN, C7orf61 and DHNA17 and a frameshift mutation in GGN in six other patients. All variants identified through exome sequencing, except for the variants in DNAH17, were located in a region of homozygosity. Familial segregation of the nonsense variant in ZPBP revealed two fertile brothers and the patient's mother to be heterozygous carriers. Paternal DNA was unavailable. Immunohistochemistry confirmed that ZPBP localises to the acrosome in human spermatozoa. Ultrastructural analysis of spermatozoa in the patient with the C7orf61 mutation revealed a mixture of round heads with no acrosomes (globozoospermia) and ovoid or irregular heads with small acrosomes frequently detached from the sperm head (acrosomal hypoplasia). LIMITATIONS, REASONS FOR CAUTION: Stringent filtering criteria were used in the exome data analysis which could result in possible pathogenic variants remaining undetected. Additionally, functional follow-up is needed for several candidate genes to confirm the impact of these mutations on normal spermatogenesis. WIDER IMPLICATIONS OF THE FINDINGS: Our study revealed an important role for mutations in ZPBP and CCDC62 in human globozoospermia as well as five new candidate genes. These findings provide a more comprehensive understanding of the genetics of male infertility and bring us closer to a complete molecular diagnosis for globozoospermia patients which would help to predict the success of reproductive treatments. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by The Netherlands Organisation for Scientific Research (918-15-667); National Health and Medical Research Council of Australia (APP1120356) and the National Council for Scientific Research (CONICET), Argentina, PIP grant 11220120100279CO. The authors have nothing to disclose.

[Genetic aspects of male infertility: From bench to clinic]. / Aspect génétique de l'infertilité masculine : de la recherche à la clinique.

OBJECTIVES: The objective of our manuscript is to review the current state of research on the genetics of male infertility, highlighting the genetic abnormalities that can lead to non-syndromic male infertility and genetic testing proposed to patients. It is intended primarily for clinicians and biologists of reproductive medicine. METHODS: A comprehensive review of the scientific literature available on PubMed was conducted using keywords related to male infertility and genetics. Since the first genes related to non-syndromic male infertility were identified after the 2000s, bibliographic research was conducted after this date. RESULTS: Thirty-three genes have been identified as responsible for non-syndromic male infertility. The evolution of techniques based on whole genome analysis has allowed the development of more successful methods in the identification of new genes and mutations inducing an infertility phenotype. Through this article, we propose, by concrete examples, a clinical approach for genetic tests considering the semen analysis alterations. CONCLUSIONS: The identification and characterization of these genes and the mutations responsible for certain infertility phenotypes allow better management and better treatment for patients as well as a better understanding of the physiopathological mechanisms of human gametogenesis.

Recent developments in genetics and medically assisted reproduction: from research to clinical applications.

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.

Recent developments in genetics and medically-assisted reproduction: from research to clinical applications†‡.

Two leading European professional societies, the European Society of Human Genetics and the European Society for Human Reproduction and Embryology, have worked together since 2004 to evaluate the impact of fast research advances at the interface of assisted reproduction and genetics, including their application into clinical practice. In September 2016, the expert panel met for the third time. The topics discussed highlighted important issues covering the impacts of expanded carrier screening, direct-to-consumer genetic testing, voiding of the presumed anonymity of gamete donors by advanced genetic testing, advances in the research of genetic causes underlying male and female infertility, utilisation of massively-parallel sequencing in preimplantation genetic testing and non-invasive prenatal screening, mitochondrial replacement in human oocytes, and additionally, issues related to cross-generational epigenetic inheritance following IVF and germline genome editing. The resulting paper represents a consensus of both professional societies involved.

Increased pregnancy rate using standardized coculture on autologous endometrial cells and single blastocyst transfer : a multicentre randomized controlled trial.

Despite excellent published results, the lack of well-designed, multicentre, randomized clinical trials results in an absence of general consensus on the efficacy of autologous endometrial cells coculture (AECC) in Assisted Reproductive Technology (ART). An open, multicentre, prospective, randomized controlled trial was designed to compare the pregnancy rate (PR) after the transfer of one blastocyst on day 5 after AECC to the transfer of one embryo on day 3 (control group). Patients were women aged 18 to 36, undergoing an ART cycle with no more than 1 embryo transfer failure. Sample size was calculated at 720 for a superiority trial involving an intermediate analysis at 300 patients. We present the results of the intermediate analysis that resulted in the study ending considering the observed difference. Three hundred thirty nine patients were randomized: 170 in the AECC group and 169 in the control group. The clinical PR per transfer was 53.4% with AECC and 37.3% in the control group (p=0.025). The quality of embryos was improved with AECC. These results suggest that implementation of the AECC technique to a large number of In-Vitro Fertilization (IVF) centres could lead to a substantial improvement in the proportion of successful assisted reproduction. The study was supported by the Laboratoires Genévrier, France.

Assisted oocyte activation overcomes fertilization failure in globozoospermic patients regardless of the DPY19L2 status.

STUDY QUESTION: Does DPY19L2 status influence intracytoplasmic sperm injection (ICSI) outcomes with or without assisted oocyte activation (AOA)? SUMMARY ANSWER: DPY19L2 mutations have no major impact on ICSI outcomes in globozoospermic patients. WHAT IS KNOWN ALREADY: Globozoospermia is a rare and severe teratozoospermia characterized by round-headed spermatozoa lacking an acrosome. Recently, it has been shown that DPY19L2 mutations can be found in a vast majority of, but not all, globozoospermic patients (66.7%). These patients suffer from primary infertility due to a sperm-related oocyte activation deficiency secondary to the absence of an acrosome that can be overcome by the application of AOA. STUDY DESIGN, SIZE, DURATION: Cohort study, retrospective, 34 patients, 83 cycles. MATERIALS, SETTING, METHODS: Clinical and biologic data were collected from 29 patients mutated for DPY19L2 and 5 non-mutated patients. In total, 35 ICSI cycles using AOA and 48 conventional ICSI cycles were included in the analysis. Patients were divided into groups according to whether or not they were mutated for DPY19L2 and whether or not they received AOA. MAIN RESULTS AND THE ROLE OF CHANCE: Regardless of the presence of a DPY19L2 mutation, the fertilization rates with AOA are restored to normal when compared with conventional ICSI in our cohort of globozoospermic patients. Also, when performing ICSI plus AOA, both mutated and non-mutated cases have similar positive hCG rates, ongoing pregnancy rates and live birth rates per transfer. On the contrary, the fertilization rate in globozoospermic patients using conventional ICSI is correlated with the presence of a DPY19L2 mutation, with slightly better, although still very low, fertilization rates in patients carrying a DPY19L2 mutation. Nevertheless, when performing conventional ICSI, both mutated and non-mutated cases have similar very low positive hCG rates, ongoing pregnancy rates and live birth rates per transfer. LIMITATIONS: A limitation of this study is the low number of included non-mutated cases. WIDER IMPLICATIONS OF THE FINDINGS: We propose a pathway for the clinical management of globozoospermic patients depending on the phenotype that includes several diagnostic and therapeutic steps. STUDY FUNDING/COMPETING INTEREST(S): None.

Assisted reproduction treatment and epigenetic inheritance.

BACKGROUND: The subject of epigenetic risk of assisted reproduction treatment (ART), initiated by reports on an increase of children with the Beckwith-Wiedemann imprinting disorder, is very topical. Hence, there is a growing literature, including mouse studies. METHODS: In order to gain information on transgenerational epigenetic inheritance and epigenetic effects induced by ART, literature databases were searched for papers on this topic using relevant keywords. RESULTS: At the level of genomic imprinting involving CpG methylation, ART-induced epigenetic defects are convincingly observed in mice, especially for placenta, and seem more frequent than in humans. Data generally provide a warning as to the use of ovulation induction and in vitro culture. In human sperm from compromised spermatogenesis, sequence-specific DNA hypomethylation is observed repeatedly. Transmittance of sperm and oocyte DNA methylation defects is possible but, as deduced from the limited data available, largely prevented by selection of gametes for ART and/or non-viability of the resulting embryos. Some evidence indicates that subfertility itself is a risk factor for imprinting diseases. As in mouse, physiological effects from ART are observed in humans. In the human, indications for a broader target for changes in CpG methylation than imprinted DNA sequences alone have been found. In the mouse, a broader range of CpG sequences has not yet been studied. Also, a multigeneration study of systematic ART on epigenetic parameters is lacking. CONCLUSIONS: The field of epigenetic inheritance within the lifespan of an individual and between generations (via mitosis and meiosis, respectively) is growing, driven by the expansion of chromatin research. ART can induce epigenetic variation that might be transmitted to the next generation.

Creation of a registry for human embryonic stem cells carrying an inherited defect: joint collaboration between ESHRE and hESCreg.

Human embryonic stem cells (hESCs), derived from human blastocysts, hold a great promise for regenerative medicine, drug development and basic research in developmental biology. Moreover, hESC lines that carry a clinically relevant inherited defect, monogenic or chromosomal, present an important tool for research into the pathophysiology of these diseases. The hESC registry (hESCreg) was started up in 2007 in order to register all stem cell lines derived in Europe (www.hescreg.eu). Because of the special nature of the hESC lines that carry an inherited disease, they are of particular interest to researchers outside the assisted reproductive technologies or stem cell fields, for instance, those involved in regenerative medicine and in medical and human genetics. To reach these researchers, and to better disseminate the information on the cell lines, a concerted action of the hESCreg together with ESHRE's Special Interest Groups in Reproductive Genetics and Stem Cells was initiated. This mini-review is a first report that will be followed by yearly reports of new lines, not unlike the reports from the Preimplantation Genetic Diagnosis Consortium or the European IVF Monitoring.

What next for preimplantation genetic screening? More randomized controlled trials needed?

The recent debate on preimplantation genetic screening (PGS) has raised questions about its routine use in clinical practice. It has been suggested that the most effective way to resolve the debate about the usefulness of PGS is to perform more well-designed and well-executed randomized controlled trials (RCTs). However, in view of the lack of evidence for the effectiveness of PGS and the accumulating evidence for its harmfulness, it is our opinion that it is unethical to perform additional RCTs for the indication advanced maternal age using cleavage stage biopsy.

ESHRE PGD consortium data collection VII: cycles from January to December 2004 with pregnancy follow-up to October 2005.

The seventh report of the ESHRE PGD Consortium is presented documenting cycles collected for the calendar year 2004 and follow-up of the pregnancies and babies born subsequent to these cycles up to October 2005. Since the beginning of the data collections, there has been a steady increase in the number of cycles, pregnancies and babies reported. For data collection VII, 45 centres have participated, reporting on 3358 cycles to oocyte retrieval (OR), 679 pregnancies and 528 babies born. Five hundred and fifty nine OR were reported for chromosomal abnormalities, 113 OR for sexing for X-linked diseases, 520 OR for monogenic diseases, 2087 OR for PGS, and 79 OR for social sexing. Data VII is compared with the cumulative data for data collections I-VI.

[Huntington disease: presymptomatic testing, prenatal diagnosis, preimplantation genetic diagnosis experience]. / Maladie de Huntington: l'expérience du test présymptomatique, du diagnostic prénatal et préimplantatoire.

Presymptomatic testing for Huntington disease has been available for 15 years. The possibility of determining the genetic status of an at-risk person for the disorder which runs in his or her family raises questions because of the absence of preventive treatments. In addition, being carrier does not allow to determine when the disease starts and how it will evolve, impairing the possibilities of planning the future. A pluridisciplinary approach to predictive testing with care before, during and after the test taking into account the medical, social and psychological aspects of the disease is good practice. At the present time, only a minority of at-risk individuals request presymptomatic testing and almost 50% do not pursue until the results. The consequences of the test may be harmful, more frequently after an unfavorable than after a favorable result. Motivations and the outcome in terms of request for prenatal testing after a carrier result are known today and the number or prenatal testing remains very limited. Preimplantation genetic testing is an alternative for couples who knows or do not their own genetic status. We report our experience in two French centres: Paris for presymptomatic and prenatal testing and Strasbourg for preimplantation diagnosis.

[Embryo donation in France: practice and difficulties. Strasbourg's experience]. / L'accueil d'embryon en France: pratiques et difficultés. L'expérience de Strasbourg.

OBJECTIVE: The aim of this study was to present the situation of embryo donation in France and around the world, to expound the difficulties of its practice and the results obtained in our centre 3 years after the introduction of this procedure. PATIENTS AND METHODS: Embryo donation in France is controlled by implemented decrees published between 1999 and 2004. The couples, who have stored frozen embryos since at least two years, were contacted for a pluridisciplinary medical consultation. The indication of embryo donation was evaluated for the recipients through a pluridisciplinary approach. RESULTS: Among the interviewed couples, 16.7% have chosen embryo donation but only half of them have completed the procedure (6% of the couples with frozen embryos). The main indications for embryo donation were a double sterility, unexplained genetic disease, ART failures (poor fertilization or bad embryo quality) and oocyte donation when the delay was too long for the couples. The pregnancy rate was 28.6% after the 21 first embryo transfers. DISCUSSION AND CONCLUSION: The results of embryo donation confirm the international experience both considering the poor number of donated embryos, medical indications and results. Embryo donation has its place among ART techniques, but one should not ignore the general debate on ethical questions raised by this procedure.

ESHRE PGD Consortium data collection VI: cycles from January to December 2003 with pregnancy follow-up to October 2004.

The sixth report of the ESHRE PGD Consortium is presented, relating to cycles collected for the calendar year 2003 and follow-up of the pregnancies and babies born up to October 2004. Since the beginning of the data collections, there has been a steady rise in the number of cycles, pregnancies and babies reported. For this report, 50 centres participated, reporting on 2984 cycles, 501 pregnancies and 373 babies born. Five hundred and twenty-nine cycles were reported for chromosomal abnormalities, 516 cycles were reported for monogenic diseases, 137 cycles were reported for sexing for X-linked diseases, 1722 cycles were reported for preimplantation genetic screening (PGS) and 80 cycles were reported for social sexing. Data VI is compared to the cumulative data for data collections I-V.

Strategies and outcomes of PGD of familial adenomatous polyposis.

Owing to adult onset of hereditary cancer, prenatal diagnosis (PND) raises numerous ethical issues on the acceptability to terminate an affected pregnancy (TOP). PND for these disorders is often considered as unacceptable by couples as well as geneticists and legal or ethical authorities, but preimplantation genetic diagnosis (PGD), even if subject to controversy, seems to be a more acceptable option. Therefore, many couples, who do not want to transmit their cancer to their children, consider PGD as their only reproductive option. This article describes our experience of PGD for familial adenomatous polyposis (FAP). Twelve couples were referred between 2000 and 2005. We developed PGD tests to detect the mutation alone, but we rapidly set up multiplex PCR combining mutation detection and indirect diagnosis. Finally, we set up duplex and triplex indirect diagnoses to be able to offer a PGD, whatever mutation was involved in familial cases. PGD strategies were based on (i) a new double allele-specific PCR approach (D-ARMS) allowing the detection of the wild-type and mutated allele; (ii) PCR fragments sizing and (iii) restriction length polymorphisms. For the 12 referrals, we developed eight tests, and 11 cycles have been performed for four couples, resulting in eight embryo transfers and five pregnancies, with the birth of one healthy boy and two ongoing pregnancies. We are now able to propose PGD to most couples at risk of transmitting FAP to their offspring, whether the mutation is familial or occurred de novo.

Chromosome abnormalities in sperm from infertile men with normal somatic karyotypes: teratozoospermia.

Teratozoospermia is characterized by the presence of spermatozoa with abnormal morphology in sperm. This condition is frequently associated with infertility and intracytoplasmic sperm injection (ICSI) is frequently used as the treatment of choice. However, the use of ICSI has created consequential debate concerning the genetic risk for the offspring. Fluorescence in situ hybridization technique (FISH), allowing the specific identification of human chromosomes in sperm nuclei, has been used to study chromosome abnormalities in sperm from men with teratozoospermia and a normal karyotype. In this review, we present studies that have tried to determine if men with a normal blood karyotype but suffering from teratozoospermia present a higher aneuploidy frequency. The literature is limited to three forms of teratozoospermia. The first group consists of "polymorphic teratozoospermia", where a majority of spermatozoa display more than one type of abnormality. In this case, only a slight increase in aneuploidy frequency is observed, which cannot be differentiated from the results observed in oligo-astheno-teratozoospermia (OAT). The second group, named "globozoospermia", is characterized by round spermatic heads, absence of acrosome and disorganization of mid-piece and tail. In this case, some studies have shown a significant, but moderate, increase in the aneuploidy frequency for acrocentrics and sex chromosomes. The aneuploidy frequency remains low, also ICSI can be proposed to these patients, but few successes occur. The third group consists of "enlarged head teratozoospermia", where almost all spermatozoa have an enlarged head, multiple tail and abnormal acrosome. In this case a very high level of missegregation is observed, leading to nearly 100% aneuploidy. In this particular group, ICSI must be refuted, and patients have to be redirected to other possibilities, like sperm donation.

ESHRE PGD Consortium data collection IV: May-December 2001.

The ESHRE PGD Consortium was formed in 1997 to survey the practice of preimplantation genetic diagnosis (PGD). Since then, three reports have been published giving an overview on PGD from an ever-increasing number of centres and reporting on an increasing number of PGD cycles and pregnancies and babies born after PGD. After these initial influential publications, important shortcomings were identified primarily on the method of data collection, i.e. with Excel spreadsheets, and in the timing of the collection (cycles were collected in a different time frame from pregnancies and babies, making the follow-up of cycles very difficult). This is why the Steering Committee has made a major investment in developing and implementing a new database in FileMaker Pro 6. It was also decided that cycles would be collected from one calendar year, as well as the pregnancies and babies ensuing from that particular calendar year. This gave us the opportunity to take a closer look at the data collected earlier, and to attempt to improve their quality. This is a report on the corrected data from the first three data collections (I-III) as well as the result of the last data collection (IV) that was completely carried out using the new database.

[Abnormal bacterial colonisation of the vagina and implantation during assisted reproduction]. / Colonisation bactérienne vaginale anormale et implantation en assistance médicale à la procréation.

OBJECTIVE: To evaluate the efficiency of our treatment of vaginal infection for couples included in an IVF program. PATIENTS AND METHODS: Microbiologic screening of vaginal flora and semen has been performed one month prior to in vitro fertilization for 951 couples in 2000. Antibiotic treatment was prescribed in case of positive culture. RESULTS: Positive microbial growths were observed from endocervical and vaginal cultures in 218 women (22.9%). The clinical pregnancy rate was 30.29% in the group of patients without growth and 30.27% in the group with positive microbial growth. The implantation rate was significantly diminished in case of bacterial growth: 14.6 compared to 19.3% (P <0.02) for sterile endocervical culture. Five main bacterial species were found at the cervical level: Candida albicans (69 cases), Ureaplasma urealyticum (49 cases), Gardnerella vaginalis (43 cases), Streptococcus B or D (24 cases) and Escherichia coli (22 cases). Positive cultures from both vagina and semen were observed for 77 couples whose clinical pregnancy rate was 19.5 vs 36.2% in case of vaginal infection alone (P <0.01) with a spontaneous miscarriage rate of 46.7 compared to 17.6% (P <0.01). DISCUSSION AND CONCLUSION: Endocervical microorganisms, even treated with adapted antibiotics, may affect embryonic implantation. Positive culture from both female and male partner may enhance this negative effect. In this case, the best strategy would be to cancel the IVF treatment.