InterviewAn Interview with Dr. Joep GeraedtsOBM Genetics Editorial OfficeLIDSEN Publishing Inc., 2000 Auburn Drive, One Chagrin Highlands, Suite 200, Beachwood, OH, USA; E-Mail: genetics@lidsen.comOBM Genetics2022, volume 6, issue 1doi:10.21926/obm.genet.2201148Received: February 17, 2022Accepted: February 17, 2022Published: February 22, 2022

This article reviews the genetic testing of infertility disorders. Genetic abnormalities can lead to disturbances of sexual development and hamper reproduction by influencing gamete production and maturation, fertilization, and embryonic development. Until now, the vast majority of detectable genetic abnormalities causing infertility were chromosomal abnormalities in both males and females. However, the number of monogenetic disorders, which play a role in disturbing fertility, such as single gene defects or complex disorders involving multiple genes in combination with environmental factors, is increasing. The common genetic causes of infertility in males are sex chromosomal abnormalities, Robertsonian translocations, cystic fibrosis transmembrane conductance regulator (CFTR) mutations, and Y chromosome microdeletions. In females, Turner syndrome, genetic causes of premature ovarian failure, such as fra(X) and complex disorders like polycystic ovary syndrome (PCOS), and endometriosis are the most prevailing. However, insight into the total impact of genetic abnormalities is increasing. This is because a growing number of mutations are detected among subfertile patients with an unknown etiology. Genetics is one of the most important yet under-emphasized causes of subfertility. Improved understanding of the genetics of infertility holds promise to define the etiology and counsel cases that were previously diagnosed with idiopathic infertility.

At the beginning of a new year it is always good to look both backwards and forwards and to highlight a few items that are relevant with respect to the long-term development of our journal. As everybody knows, the principle of open access publishing is that the authors pay fees (the article‐processing charges or APCs) to publish in the journal rather than that the readers pay subscription costs for the journal. Three years ago, OBM Genetics started as an open access journal publishing its first papers totally free of charge and it has done so till the end of 2019 in order to attract high-quality papers. This policy has been successful.

Mitochondrial diseases represent the most common inborn errors of metabolism. The overwhelming majority of mitochondrial diseases (about 85 %) are caused by mutations of nuclear genes of oxidative phosphorylation. The remaining 15 % are caused by mtDNA mutations. The familial mtDNA mutations are exclusively inherited from the mother. Dysfunction of oocyte mitochondria is believed to result in poor developmental competence of oocytes in older infertility patients. Therefore, a group of patients underwent ooplasmic transfer from fertile donor oocytes to rejuvinate their developmentally compromised oocytes. However, this series was stopped, because two foetuses were affected by Turner’s syndrome and a second issue was related to the risks of mitochondrial heteroplasmy. Instead treatments with heterologous mitochondria, autologous transfer has been introduced instead. However, interim analysis of a controlled randomised trial has shown that autologous germline mitochondrial energy transfer is not a feasible treatment to improve embryo quality in IVF. For the prevention of the transmission of mtDNA mutations in principle four methods are available: preimplantation genetic diagnosis (PGD) or prenatal diagnosis (PND) followed by the selection of the best embryo or foetus; the use of complete donor oocytes; mitochondrial replacement therapy (MRT) and genome editing. Not each of these is applicable in reproductive medicine yet. The stage of development will be discussed.

STUDY QUESTIONDoes 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 ANSWERPGT-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 ALREADYPGT-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, DURATIONThis 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, METHODSInfertile 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 CHANCEOf 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 CAUTIONThe 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 FINDINGSThe 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 NUMBERNCT01532284.TRIAL REGISTRATION DATE7 February 2012.DATE OF FIRST PATIENT’S ENROLMENT25 June 2012.

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.

Much of the published medical research is apparently flawed, cannot be replicated and/or has limited or no utility. This article presents an overview of the current landscape of biomedical research, identifies problems associated with common study designs and considers potential solutions. Randomized clinical trials, observational studies, systematic reviews and meta-analyses are discussed in terms of their inherent limitations and potential ways of improving their conduct, analysis and reporting. The current emphasis on statistical significance needs to be replaced by sound design, transparency and willingness to share data with a clear commitment towards improving the quality and utility of clinical research.

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.

Both preimplantation genetic testing and prenatal testing are powerful tools to tackle the transmission of inherited disorders in families carrying the diseases from generation to generation. This article presents an overview of the current landscape of both methods and identifies the pros and cons of each of these reproductive options.

Prenatal diagnostics and preimplantation genetic screening are safe and efficient methods to help parents with inherited mutations for severe diseases to have healthy children. Its expansion into adult‐onset diseases and cancer raises challenges for regulation of assisted reproductive technologies and coverage by healthcare systems.

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Mark Stoneking, who is a member of the Editorial Board of OBM Genetics has written a textbook on molecular anthropology

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.

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.

Zusammenfassung Im Jahr 1995 wurde die Präimplantationsdiagnostik (PID) auf experimenteller Ebene in Maastricht eingeführt. Seit 2003 ist sie Bestandteil des Erstattungssystems des niederländischen Ministry Public Health, Welfare and Sport. PID wird nur Paaren ermöglicht, die mit einem Risiko für eine schwerwiegende monogene Erkrankung, strukturellen Chromosomenanomalien oder mitochondrialen Erkrankungen bei ihren Nachkommen rechnen müssen. Ein Aneuploidiescreening zur Verbesserung der Erfolgsraten und assistierte Reproduktionstechnologien wie In-vitro-Fertilisation (IVF) oder Intrazytoplasmatische Spermieninjektion (ICSI) waren nie Gegenstand des PID-Programms. 2008 beschloss die niederländische Regierung, eine „National Indications Commission“ einzurichten, die bei neuen Krankheitsentitäten prüfen soll, ob die Kriterien für die Zulassung einer PID erfüllt sind: 1. die Schwere und Art der Erkrankung, 2. bestehende Möglichkeiten für Prävention und Behandlung, 3. zusätzliche medizinische Kriterien und 4. psychologische und ethische Faktoren. Geschlechtsbestimmung (aus sozialen Gründen) ist auch in den Niederlanden, wie in den meisten europäischen Ländern, nicht erlaubt. Eine PID für die Diagnose sog. Rettungskinder ist nur dann erlaubt, wenn unabhängig hiervon eine Indikation für eine PID der genetischen Erkrankung besteht. HLA-Typisierung ohne Indikation für eine genetische Erkrankung ist hingegen nicht zulässig. Das Maastricht University Medical Center (UMC) übernimmt die gesamte genetische Diagnostik und verfügt über die mit den Universitäten von Utrecht, Groningen und Amsterdam abgestimmten (University Medical Centre (UMC) Utrecht, University Medical Centre (UMC) Groningen and the Amsterdam Medical Centre (AMC)) SOPs für die PID-Transporte. Zwischen 1995 und 2015 wurden insgesamt 2870 Zyklen bei 1430 Paaren durchgeführt. Der häufigste Grund für eine Überweisung zur PID war die Huntington-Krankheit, gefolgt von erblichem Brust- und Eierstockkrebs. Unter den weiteren Indikationen sind weit mehr autosomal-dominante genetisch bedingte Erkrankungen als autosomal-rezessive. Unter den zuletzt genannten stehen an erster Stelle Mukoviszidose und danach die spinale Muskelatrophie (SMA). Die Erfolgsrate liegt bei 20 % pro Zyklusbeginn und bei 25 % pro Embryonentransfer. Die Anzahl der Behandlungszyklen pro Paar liegt fast exakt bei 2,0.

About 25 years ago, preimplantation genetic diagnosis (PGD) was introduced as an alternative to prenatal diagnosis for the detection of monogenic, mitochondrial and chromosomal disorders. After IVF or (mostly) ICSI, either polar bodies, blastomeres or trophectoderm cells are biopsied from the oocyte or preimplantation embryo and tested using a molecular method. Unaffected embryos are selected for transfer to the uterus, thereby preventing termination of pregnancy.In 1997, the European Society of Human Reproduction and Embryology (ESHRE) PGD Consortium was formed as part of the ESHRE special interest group on reproductive genetics, in order to undertake a long-term study of the efficacy and clinical outcome of PGD. In December 1999, the first PGD Consortium report was published. Since then, 13 data collections have been published. Furthermore, for the most recent years (2013-2015), unpublished data have been collected from about half of all 121 (89 European) members of the PGD Consortium.Although not as much as before, legislation, regulation and service of PGD still strongly vary among European countries. This has led to patients crossing borders to seek care.In the early days, the pattern of indications was more or less a reflection of the genetic disorders requiring prenatal diagnosis. Interestingly, in a number of countries an increasing number of tests are performed for adult-onset diseases, showing that, in these cases, PGD seems more acceptable than prenatal diagnosis.The most important chromosomal indications for PGD are reciprocal translocations (both male and female carriers).It can be noticed that cleavage stage biopsy is very slowly replaced by blastocyst stage biopsy.There is a normal percentage of pregnancies that end in a miscarriage. The number of terminations of pregnancy is extremely low. About one in six pregnancies will result in the birth of a twin and the number of higher-order multiples is very limited. In a small number of cases, misdiagnoses have been reported.