Pathogenic variants in E3 ubiquitin ligase RLIM/RNF12 lead to a syndromic X-linked intellectual disability and behavior disorder.

RLIM, also known as RNF12, is an X-linked E3 ubiquitin ligase acting as a negative regulator of LIM-domain containing transcription factors and participates in X-chromosome inactivation (XCI) in mice. We report the genetic and clinical findings of 84 individuals from nine unrelated families, eight of whom who have pathogenic variants in RLIM (RING finger LIM domain-interacting protein). A total of 40 affected males have X-linked intellectual disability (XLID) and variable behavioral anomalies with or without congenital malformations. In contrast, 44 heterozygous female carriers have normal cognition and behavior, but eight showed mild physical features. All RLIM variants identified are missense changes co-segregating with the phenotype and predicted to affect protein function. Eight of the nine altered amino acids are conserved and lie either within a domain essential for binding interacting proteins or in the C-terminal RING finger catalytic domain. In vitro experiments revealed that these amino acid changes in the RLIM RING finger impaired RLIM ubiquitin ligase activity. In vivo experiments in rlim mutant zebrafish showed that wild type RLIM rescued the zebrafish rlim phenotype, whereas the patient-specific missense RLIM variants failed to rescue the phenotype and thus represent likely severe loss-of-function mutations. In summary, we identified a spectrum of RLIM missense variants causing syndromic XLID and affecting the ubiquitin ligase activity of RLIM, suggesting that enzymatic activity of RLIM is required for normal development, cognition and behavior.

Preimplantation genetic testing for aneuploidy by microarray analysis of polar bodies in advanced maternal age: a randomized clinical trial.

STUDY QUESTION: Does preimplantation genetic testing for aneuploidy (PGT-A) by comprehensive chromosome screening (CCS) of the first and second polar body to select embryos for transfer increase the likelihood of a live birth within 1 year in advanced maternal age women aged 36-40 years planning an ICSI cycle, compared to ICSI without chromosome analysis? SUMMARY ANSWER: PGT-A by CCS in the first and second polar body to select euploid embryos for transfer does not substantially increase the live birth rate in women aged 36-40 years. WHAT IS KNOWN ALREADY: PGT-A has been used widely to select embryos for transfer in ICSI treatment, with the aim of improving treatment effectiveness. Whether PGT-A improves ICSI outcomes and is beneficial to the patients has remained controversial. STUDY DESIGN, SIZE, DURATION: This is a multinational, multicentre, pragmatic, randomized clinical trial with intention-to-treat analysis. Of 396 women enroled between June 2012 and December 2016, 205 were allocated to CCS of the first and second polar body (study group) as part of their ICSI treatment cycle and 191 were allocated to ICSI treatment without chromosome screening (control group). Block randomization was performed stratified for centre and age group. Participants and clinicians were blinded at the time of enrolment until the day after intervention. PARTICIPANTS/MATERIALS, SETTING, METHODS: Infertile couples in which the female partner was 36-40 years old and who were scheduled to undergo ICSI treatment were eligible. In those assigned to PGT-A, array comparative genomic hybridization (aCGH) analysis of the first and second polar bodies of the fertilized oocytes was performed using the 24sure array of Illumina. If in the first treatment cycle all oocytes were aneuploid, a second treatment with PB array CGH was offered. Participants in the control arm were planned for ICSI without PGT-A. Main exclusion criteria were three or more previous unsuccessful IVF or ICSI cycles, three or more clinical miscarriages, poor response or low ovarian reserve. The primary outcome was the cumulative live birth rate after fresh or frozen embryo transfer recorded over 1 year after the start of the intervention. MAIN RESULTS AND THE ROLE OF CHANCE: Of the 205 participants in the chromosome screening group, 50 (24%) had a live birth with intervention within 1 year, compared to 45 of the 191 in the group without intervention (24%), a difference of 0.83% (95% CI: -7.60 to 9.18%). There were significantly fewer participants in the chromosome screening group with a transfer (relative risk (RR) = 0.81; 95% CI: 0.74-0.89) and fewer with a miscarriage (RR = 0.48; 95% CI: 0.26-0.90). LIMITATIONS, REASONS FOR CAUTION: The targeted sample size was not reached because of suboptimal recruitment; however, the included sample allowed a 90% power to detect the targeted increase. Cumulative outcome data were limited to 1 year. Only 11 patients out of 32 with exclusively aneuploid results underwent a second treatment cycle in the chromosome screening group. WIDER IMPLICATIONS OF THE FINDINGS: The observation that the similarity in birth rates was achieved with fewer transfers, less cryopreservation and fewer miscarriages points to a clinical benefit of PGT-A, and this form of embryo selection may, therefore, be considered to minimize the number of interventions while producing comparable outcomes. Whether these benefits outweigh drawbacks such as the cost for the patient, the higher workload for the IVF lab and the potential effect on the children born after prolonged culture and/or cryopreservation remains to be shown. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the European Society of Human Reproduction and Embryology. Illumina provided microarrays and other consumables necessary for aCGH testing of polar bodies. M.B.'s institution (UZBrussel) has received educational grants from IBSA, Ferring, Organon, Schering-Plough, Merck and Merck Belgium. M.B. has received consultancy and speakers' fees from Organon, Serono Symposia and Merck. G.G. has received personal fees and non-financial support from MSD, Ferring, Merck-Serono, Finox, TEVA, IBSA, Glycotope, Abbott and Gedeon-Richter as well as personal fees from VitroLife, NMC Healthcare, ReprodWissen, BioSilu and ZIVA. W.V., C.S., P.M.B., V.G., G.A., M.D., T.E.G., L.G., G.Ka., G.Ko., J.L., M.C.M., M.P., A.S., M.T., K.V., J.G. and K.S. declare no conflict of interest. TRIAL REGISTRATION NUMBER: NCT01532284. TRIAL REGISTRATION DATE: 7 February 2012. DATE OF FIRST PATIENT'S ENROLMENT: 25 June 2012.

Embryo selection and democratic control.

Recently, American colleagues called for a systematic collection of anonymized data on how many embryos and foetuses are deselected per institution per year, and for which conditions. These authors argued that if this information would be reported to a government agency or international body, the information would provide a baseline against which jurisdiction-specific trends in selection could be assessed. People who have disabilities, together with other key stakeholders, laypeople and experts, would then be in a position to assess the social impact of human selecting technologies and to make recommendations for action to mitigate negative effects as appropriate. However, such a systematic data collection does already exist in the Netherlands and has been in place for more than 30 years. It was first introduced to monitor the practise of prenatal diagnosis by the eight licence holders sending in all data to the Minister of Public Health, Welfare and Sports. Later, the same method was expanded to preimplantation genetic diagnosis. For 8 years, these data have been discussed in the parliament, which shows that the practice of embryo selection can indeed be kept under democratic control, albeit retrospectively.

PGD for the m.14487 T>C mitochondrial DNA mutation resulted in the birth of a healthy boy.

We report on the first PGD performed for the m.14487 T>C mitochondrial DNA (mtDNA) mutation in the MT-ND6 gene, associated with Leigh syndrome. The female carrier gave birth to a healthy baby boy at age 42. This case adds to the successes of PGD for mtDNA mutations.

DNA Methylation Profiling of Uniparental Disomy Subjects Provides a Map of Parental Epigenetic Bias in the Human Genome.

Genomic imprinting is a mechanism in which gene expression varies depending on parental origin. Imprinting occurs through differential epigenetic marks on the two parental alleles, with most imprinted loci marked by the presence of differentially methylated regions (DMRs). To identify sites of parental epigenetic bias, here we have profiled DNA methylation patterns in a cohort of 57 individuals with uniparental disomy (UPD) for 19 different chromosomes, defining imprinted DMRs as sites where the maternal and paternal methylation levels diverge significantly from the biparental mean. Using this approach we identified 77 DMRs, including nearly all those described in previous studies, in addition to 34 DMRs not previously reported. These include a DMR at TUBGCP5 within the recurrent 15q11.2 microdeletion region, suggesting potential parent-of-origin effects associated with this genomic disorder. We also observed a modest parental bias in DNA methylation levels at every CpG analyzed across ∼1.9 Mb of the 15q11-q13 Prader-Willi/Angelman syndrome region, demonstrating that the influence of imprinting is not limited to individual regulatory elements such as CpG islands, but can extend across entire chromosomal domains. Using RNA-seq data, we detected signatures consistent with imprinted expression associated with nine novel DMRs. Finally, using a population sample of 4,004 blood methylomes, we define patterns of epigenetic variation at DMRs, identifying rare individuals with global gain or loss of methylation across multiple imprinted loci. Our data provide a detailed map of parental epigenetic bias in the human genome, providing insights into potential parent-of-origin effects.

Preimplantation genetic screening 2.0: the theory.

During the last few years a new generation of preimplantation genetic screening (PGS) has been introduced. In this paper, an overview of the different aspects of this so-called PGS 2.0 with respect to the why (what are the indications), the when (which developmental stage, i.e. which material should be studied) and the how (which molecular technique should be used) is given. With respect to the aims it is clear that PGS 2.0 can be used for a variety of indications. However, the beneficial effect of PGS 2.0 has not been proved yet in RCTs. It is clear that cleavage stage is not the optimal stage for biopsy. Almost all advocates of PGS 2.0 prefer trophectoderm biopsy. There are many new methods that allow the study of complete aneuploidy with respect to one or more of the 24 chromosomes. Because of the improved vitrification methods, selection of fresh embryos for transfer is more and more often replaced by frozen embryo transfer. The main goal of PGS has always been the improvement of IVF success. However, success is defined by different authors in many different ways. This makes it very difficult to compare the outcomes of different studies. In conclusion, the introduction of PGS 2.0 will depend on the success of the new biopsy strategies in combination with the analysis of all 24 chromosomes. It remains to be seen which approach will be the most successful and for which specific groups of patients.

The why, the how and the when of PGS 2.0: current practices and expert opinions of fertility specialists, molecular biologists, and embryologists.

STUDY QUESTION: We wanted to probe the opinions and current practices on preimplantation genetic screening (PGS), and more specifically on PGS in its newest form: PGS 2.0? STUDY FINDING: Consensus is lacking on which patient groups, if any at all, can benefit from PGS 2.0 and, a fortiori, whether all IVF patients should be offered PGS. WHAT IS KNOWN ALREADY: It is clear from all experts that PGS 2.0 can be defined as biopsy at the blastocyst stage followed by comprehensive chromosome screening and possibly combined with vitrification. Most agree that mosaicism is less of an issue at the blastocyst stage than at the cleavage stage but whether mosaicism is no issue at all at the blastocyst stage is currently called into question. STUDY DESIGN, SAMPLES/MATERIALS, METHODS: A questionnaire was developed on the three major aspects of PGS 2.0: the Why, with general questions such as PGS 2.0 indications; the How, specifically on genetic analysis methods; the When, on the ideal method and timing of embryo biopsy. Thirty-five colleagues have been selected to address these questions on the basis of their experience with PGS, and demonstrated by peer-reviewed publications, presentations at meetings and participation in the discussion. The first group of experts who were asked about 'The Why' comprised fertility experts, the second group of molecular biologists were asked about 'The How' and the third group of embryologists were asked about 'The When'. Furthermore, the geographical distribution of the experts has been taken into account. Thirty have filled in the questionnaire as well as actively participated in the redaction of the current paper. MAIN RESULTS AND THE ROLE OF CHANCE: The 30 participants were from Europe (Belgium, Germany, Greece, Italy, Netherlands, Spain, UK) and the USA. Array comparative genome hybridization is the most widely used method amongst the participants, but it is slowly being replaced by massive parallel sequencing. Most participants offering PGS 2.0 to their patients prefer blastocyst biopsy. The high efficiency of vitrification of blastocysts has added a layer of complexity to the discussion, and it is not clear whether PGS in combination with vitrification, PGS alone, or vitrification alone, followed by serial thawing and eSET will be the favoured approach. The opinions range from in favour of the introduction of PGS 2.0 for all IVF patients, over the proposal to use PGS as a tool to rank embryos according to their implantation potential, to scepticism towards PGS pending a positive outcome of robust, reliable and large-scale RCTs in distinct patient groups. LIMITATIONS, REASONS FOR CAUTION: Care was taken to obtain a wide spectrum of views from carefully chosen experts. However, not all invited experts agreed to participate, which explains a lack of geographical coverage in some areas, for example China. This paper is a collation of current practices and opinions, and it was outside the scope of this study to bring a scientific, once-and-for-all solution to the ongoing debate. WIDER IMPLICATIONS OF THE FINDINGS: This paper is unique in that it brings together opinions on PGS 2.0 from all different perspectives and gives an overview of currently applied technologies as well as potential future developments. It will be a useful reference for fertility specialists with an expertise outside reproductive genetics. LARGE SCALE DATA: none. STUDY FUNDING AND COMPETING INTERESTS: No specific funding was obtained to conduct this questionnaire.

Current issues in medically assisted reproduction and genetics in Europe: research, clinical practice, ethics, legal issues and policy.

STUDY QUESTION: How has the interface between genetics and assisted reproduction technology (ART) evolved since 2005? SUMMARY ANSWER: The interface between ART and genetics has become more entwined as we increase our understanding about the genetics of infertility and we are able to perform more comprehensive genetic testing. WHAT IS KNOWN ALREADY: In March 2005, a group of experts from the European Society of Human Genetics and European Society of Human Reproduction and Embryology met to discuss the interface between genetics and ART and published an extended background paper, recommendations and two Editorials. STUDY DESIGN, SIZE, DURATION: An interdisciplinary workshop was held, involving representatives of both professional societies and experts from the European Union Eurogentest2 Coordination Action Project. PARTICIPANTS/MATERIALS, SETTING, METHODS: In March 2012, a group of experts from the European Society of Human Genetics, the European Society of Human Reproduction and Embryology and the EuroGentest2 Coordination Action Project met to discuss developments at the interface between clinical genetics and ART. MAIN RESULTS AND THE ROLE OF CHANCE: As more genetic causes of reproductive failure are now recognized and an increasing number of patients undergo testing of their genome prior to conception, either in regular health care or in the context of direct-to-consumer testing, the need for genetic counselling and PGD may increase. Preimplantation genetic screening (PGS) thus far does not have evidence from RCTs to substantiate that the technique is both effective and efficient. Whole genome sequencing may create greater challenges both in the technological and interpretational domains, and requires further reflection about the ethics of genetic testing in ART and PGD/PGS. Diagnostic laboratories should be reporting their results according to internationally accepted accreditation standards (ISO 15189). Further studies are needed in order to address issues related to the impact of ART on epigenetic reprogramming of the early embryo. LIMITATIONS, REASONS FOR CAUTION: The legal landscape regarding assisted reproduction is evolving, but still remains very heterogeneous and often contradictory. The lack of legal harmonization and uneven access to infertility treatment and PGD/PGS fosters considerable cross-border reproductive care in Europe, and beyond. WIDER IMPLICATIONS OF THE FINDINGS: This continually evolving field requires communication between the clinical genetics and IVF teams and patients to ensure that they are fully informed and can make well-considered choices. STUDY FUNDING/COMPETING INTERESTS: Funding was received from ESHRE, ESHG and EuroGentest2 European Union Coordination Action project (FP7 - HEALTH-F4-2010-26146) to support attendance at this meeting.

Hereditary breast and ovarian cancer and reproduction: an observational study on the suitability of preimplantation genetic diagnosis for both asymptomatic carriers and breast cancer survivors.

Preimplantation genetic diagnosis (PGD) is a reproductive option for BRCA1/2 mutation carriers wishing to avoid transmission of the predisposition for hereditary breast and ovarian cancer (HBOC) to their offspring. Embryos obtained by in vitro fertilisation (IVF/ICSI) are tested for the presence of the mutation. Only BRCA-negative embryos are transferred into the uterus. The suitability and outcome of PGD for HBOC are evaluated in an observational cohort study on treatments carried out in two of Western-Europe's largest PGD centres from 2006 until 2012. Male carriers, asymptomatic female carriers and breast cancer survivors were eligible. If available, PGD on embryos cryopreserved before chemotherapy was possible. Generic PGD-PCR tests were developed based on haplotyping, if necessary combined with mutation detection. 70 Couples underwent PGD for BRCA1/2. 42/71 carriers (59.2 %) were female, six (14.3 %) of whom have had breast cancer prior to PGD. In total, 145 PGD cycles were performed. 720 embryos were tested, identifying 294 (40.8 %) as BRCA-negative. Of fresh IVF/PGD cycles, 23.9 % resulted in a clinical pregnancy. Three cycles involved PGD on embryos cryopreserved before chemotherapy; two of these women delivered a healthy child. Overall, 38 children were liveborn. Two BRCA1 carriers were diagnosed with breast cancer shortly after PGD treatment, despite negative screening prior to PGD. PGD for HBOC proved to be suitable, yielding good pregnancy rates for asymptomatic carriers as well as breast cancer survivors. Because of two cases of breast cancer shortly after treatment, maternal safety of IVF(PGD) in female carriers needs further evaluation.

Current issues in medically assisted reproduction and genetics in Europe: research, clinical practice, ethics, legal issues and policy. European Society of Human Genetics and European Society of Human Reproduction and Embryology.

In March 2005, a group of experts from the European Society of Human Genetics and European Society of Human Reproduction and Embryology met to discuss the interface between genetics and assisted reproductive technology (ART), and published an extended background paper, recommendations and two Editorials. Seven years later, in March 2012, a follow-up interdisciplinary workshop was held, involving representatives of both professional societies, including experts from the European Union Eurogentest2 Coordination Action Project. The main goal of this meeting was to discuss developments at the interface between clinical genetics and ARTs. As more genetic causes of reproductive failure are now recognised and an increasing number of patients undergo testing of their genome before conception, either in regular health care or in the context of direct-to-consumer testing, the need for genetic counselling and preimplantation genetic diagnosis (PGD) may increase. Preimplantation genetic screening (PGS) thus far does not have evidence from randomised clinical trials to substantiate that the technique is both effective and efficient. Whole-genome sequencing may create greater challenges both in the technological and interpretational domains, and requires further reflection about the ethics of genetic testing in ART and PGD/PGS. Diagnostic laboratories should be reporting their results according to internationally accepted accreditation standards (International Standards Organisation - ISO 15189). Further studies are needed in order to address issues related to the impact of ART on epigenetic reprogramming of the early embryo. The legal landscape regarding assisted reproduction is evolving but still remains very heterogeneous and often contradictory. The lack of legal harmonisation and uneven access to infertility treatment and PGD/PGS fosters considerable cross-border reproductive care in Europe and beyond. The aim of this paper is to complement previous publications and provide an update of selected topics that have evolved since 2005.

Fertility preservation in female classic galactosemia patients.

Almost every female classic galactosemia patient develops primary ovarian insufficiency (POI) as a diet-independent complication of the disease. This is a major concern for patients and their parents, and physicians are often asked about possible options to preserve fertility. Unfortunately, there are no recommendations on fertility preservation in this group. The unique pathophysiology of classic galactosemia with a severely reduced follicle pool at an early age requires an adjusted approach. In this article recommendations for physicians based on current knowledge concerning galactosemia and fertility preservation are made. Fertility preservation is only likely to be successful in very young prepubertal patients. In this group, cryopreservation of ovarian tissue is currently the only available technique. However, this technique is not ready for clinical application, it is considered experimental and reduces the ovarian reserve. Fertility preservation at an early age also raises ethical questions that should be taken into account. In addition, spontaneous conception despite POI is well described in classic galactosemia. The uncertainty surrounding fertility preservation and the significant chance of spontaneous pregnancy warrant counseling towards conservative application of these techniques. We propose that fertility preservation should only be offered with appropriate institutional research ethics approval to classic galactosemia girls at a young prepubertal age.

PGD for hereditary breast and ovarian cancer: the route to universal tests for BRCA1 and BRCA2 mutation carriers.

Preimplantation Genetic Diagnosis (PGD) is a method of testing in vitro embryos as an alternative to prenatal diagnosis with possible termination of pregnancy in case of an affected child. Recently, PGD for hereditary breast and ovarian cancer caused by BRCA1 and BRCA2 mutations has found its way in specialized labs. We describe the route to universal single-cell PGD tests for carriers of BRCA1/2 mutations. Originally, mutation-specific protocols with one or two markers were set up and changed when new couples were not informative. This route of changing protocols was finalized after 2 years with universal tests for both BRCA1 and BRCA2 mutation carriers based on haplotyping of, respectively, 6 (BRCA1) and 8 (BRCA2) microsatellite markers in a multiplex PCR. Using all protocols, 30 couples had a total of 47 PGD cycles performed. Eight cycles were cancelled upon IVF treatment due to hypostimulation. Of the remaining 39 cycles, a total of 261 embryos were biopsied and a genetic diagnosis was obtained in 244 (93%). In 34 of the 39 cycles (84.6%), an embryo transfer was possible and resulted in 8 pregnancies leading to a fetal heart beat per oocyte retrieval of 20.5% and a fetal heart beat per embryonic transfer of 23.5%. The preparation time and costs for set-up and validation of tests are minimized. The informativity of microsatellite markers used in the universal PGD-PCR tests is based on CEPH and deCODE pedigrees, making the tests applicable in 90% of couples coming from these populations.

Comprehensive embryo testing. Experts' opinions regarding future directions: an expert panel study on comprehensive embryo testing.

STUDY QUESTION: What do scientists in the field of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS) consider to be the future direction of comprehensive embryo testing? SUMMARY ANSWER: Although there are many biological and technical limitations, as well as uncertainties regarding the meaning of genetic variation, comprehensive embryo testing will impact the IVF/PGD practice and a timely ethical reflection is needed. WHAT IS KNOWN ALREADY: Comprehensive testing using microarrays is currently being introduced in the context of PGD and PGS, and it is to be expected that whole-genome sequencing will also follow. Current ethical and empirical sociological research on embryo testing focuses on PGD as it is practiced now. However, empirical research and systematic reflection regarding the impact of comprehensive techniques for embryo testing is missing. STUDY DESIGN, SIZE AND DURATION: In order to understand the potential of this technology and to be able to adequately foresee its implications, we held an expert panel with seven pioneers in PGD. PARTICIPANTS/MATERIALS, SETTING, METHODS: We conducted an expert panel in October 2011 with seven PGD pioneers from Belgium, The Netherlands, Germany and the UK. MAIN RESULTS AND THE ROLE OF CHANCE: Participants expected the use of comprehensive techniques in the context of PGD. However, the introduction of these techniques in embryo testing requires timely ethical reflection as it involves a shift from choosing an embryo without a particular genetic disease (i.e. PGD) or most likely to result in a successful pregnancy (i.e. PGS) to choosing the best embryo based on a much wider set of criteria. Such ethical reflection should take account of current technical and biological limitations and also of current uncertainties with regard to the meaning of genetic variance. However, ethicists should also not be afraid to look into the future. There was a general agreement that embryo testing will be increasingly preceded by comprehensive preconception screening, thus enabling smart combinations of genetic testing. LIMITATIONS, REASONS FOR CAUTION: The group was composed of seven participants from four Western Europe countries. As willingness to participate in this study may be connected with expectations regarding the pace and direction of future developments, selection bias cannot be excluded. WIDER IMPLICATIONS OF THE FINDINGS: The introduction of comprehensive screening techniques in embryo testing calls for further ethical reflection that is grounded in empirical work. Specifically, there is a need for studies querying the opinions of infertile couples undergoing IVF/PGS regarding the desirability of embryo screening beyond aneuploidy. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by the CSG, Centre for Society and Life Sciences (project number: 70.1.074). The authors declare no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Preimplantation genetic diagnosis in mitochondrial DNA disorders: challenge and success.

BACKGROUND: Mitochondrial or oxidative phosphorylation diseases are relatively frequent, multisystem disorders; in about 15% of cases they are caused by maternally inherited mitochondrial DNA (mtDNA) mutations. Because of the possible severity of the phenotype, the lack of effective treatment, and the high recurrence risk for offspring of carrier females, couples wish to prevent the transmission of these mtDNA disorders to their offspring. Prenatal diagnosis is problematic for several reasons, and concern the often poor correlation between mutation percentages and disease severity and the uncertainties about the representativeness of a fetal sample. A new option for preventing transmission of mtDNA disorders is preimplantation genetic diagnosis (PGD), which circumvents these problems by transferring an embryo below the threshold of clinical expression. METHODS: We present the data on nine PGD cycles in four female carriers of mitochondrial diseases: three mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) (m.3243A>G), and one Leigh (m.8993T>G). Our threshold for transfer after PGD is 15% for the m.3243A>G mutation and 30% for the m.8993T>G mutation. RESULTS: All four female carriers produced embryos eligible for transfer. The m.8993T>G mutation in oocytes/embryos showed more skewing than the m.3243A>G. In about 80% of the embryos the mutation load in the individual blastomeres was fairly constant (interblastomere differences <10%). However, in around 11% (in embryos with the m.3243A>G mutation only), the mutation load differed substantially (>15%) between blastomeres of a single embryo, mostly as a result of one outlier. The m.8993T>G carrier became pregnant and gave birth to a healthy son. CONCLUSIONS: PGD provides carriers of mtDNA mutations the opportunity to conceive healthy offspring.

Best practices of ASRM and ESHRE: a journey through reproductive medicine.

BACKGROUND: The American Society for Reproductive Medicine (ASRM) and the European Society of Human Reproduction and Embryology (ESHRE) are the two largest societies in the world whose members comprise the major experts and professionals working in the field of reproductive medicine and embryology. These societies have never before had a joint scientific meeting. METHOD(S): A 3-day meeting was planned and took place in March of 2012. The goal was to present and debate key topics, as well as modes of practice in reproductive medicine and to discuss recent developments in the field. RESULT(S): Presentations by members of ASRM and ESHRE were of three types: 'state of the art' lectures, 'back-to-back' presentations of two points of view and debates. CONCLUSION(S): For the first time, ASRM and ESHRE held a joint meeting where a special emphasis was given to presentations on the hottest topics in the field. Although different opinions and approaches sometimes exist on the two sides of the Atlantic, an appreciation and acceptance of these differences was evident, and there was more commonality than divergence of opinion.