Preimplantation genetic diagnosis in female and male carriers of reciprocal translocations: clinical outcome until delivery of 312 cycles

Carriers of reciprocal translocations (rcp) are known to be at risk for reproductive difficulties. Preimplantation genetic diagnosis (PGD) is one of the options these carriers have to try in order to fulfil their desire to have a child. In the present study, we retrospectively looked at the results of 11 years (1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007) of PGD for rcp in our center to improve the reproductive counseling of these carriers. During this period 312 cycles were performed for 69 male and 73 female carriers. The mean female age was 32.8 years, the mean male age 35.8 years. Most carriers were diagnosed with a translocation because of fertility problems or recurrent miscarriages, and most of them opted for PGD to avoid these problems. In 150 of the 312 cycles, embryo transfer (ET) was feasible and 40 women had a successful singleton or twin pregnancy. This gives a live birth delivery rate of 12.8% per started cycle and of 26.7% per cycle with ET. Owing to the large number of abnormal embryos, PGD cycles for rcp often lead to cancellation of ET, explaining the low success rate when expressed per cycle with oocyte pick-up. Once ET was feasible, the live birth delivery rate was similar to that of PGD in general at our center. PGD is therefore an established option for specific reciprocal translocation carriers

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

Blurring boundaries. Interviews with PGT couples about comprehensive chromosome screening

OBJECTIVE: Comprehensive chromosome examination is a promising approach to Preimplantation Genetic Testing (PGT). Next to testing of specific chromosomes, such as in the case of reduced fertility due to chromosomal translocations, it allows testing of all chromosomes. Hence it potentially reduces the time to pregnancy and the risk of miscarriage. But comprehensive testing also introduces some ethical issues. For example, what is the role of the professional in the decision making regarding embryos with chromosomal abnormalities that are potentially viable? Which chromosomal abnormalities should be communicated to people undergoing fertility treatment? With this paper we wanted to explore the ethical issues related to comprehensive chromosome screening in Preimplantation Genetic Testing. DESIGN: In order to explore these issues, we interviewed seven couples undergoing PGT for chromosomal translocations at the VUB University Hospital, Belgium. We presented them with three fictional cases: the transfer of an embryo with trisomy 21, of an embryo with a sex chromosome aneuploidy and of an embryo with a chromosomal microdeletion. RESULTS: We found that opinions regarding the role of fertility professionals in deciding which embryos to transfer were mixed. Moreover, where to draw the line between healthy and unhealthy embryos was unclear. We also found that couples, although they thought that comprehensive chromosome testing had certain benefits, also considered the increased waiting time for transfer a heavy burden. CONCLUSIONS: In the light of comprehensive chromosome screening of embryos, persons undergoing fertility treatment may have views on the burdens and benefits of the techniques that are not analogous to the views of professionals.status: publishe

METHYLATION OF THE CPG SITES IN THE MYOTONIC DYSTROPHY LOCUS DOES NOT CORRELATE WITH CTG EXPANSION SIZE OR WITH THE CONGENITAL FORM OF THE DISEASE

International audienceWe have studied the methylation status of the sequence 152 nucleotides upstream of the CTG repeat of the DM1 locus in patients' peripheral blood. We used the methylation-sensitive endonucleases SacII, HpaII and HhaI, followed by PCR. This allowed to correlate the methylation status of each CTG allele with its size. Contrary to previous findings (Steinbach P et al., 1988, Am.J.Hum.Genet. 62:278-285), only the SacII site is often but not always differentially methylated amongst expanded CTG alleles. Importantly, this methylation was not restricted to congenital DM1, nor to large expansions, as it was also present in DM1 patients with a classical phenotype and various expansion sizes. On the other hand, we did not find any methylated alleles on the HhaI and HpaII sites, as was reported by Steinbach et al, which is in line with the results of Shaw and collaborators (1993, J.Med.Genet. 30:189-192). The size range of the repeat expansions with methylation was from as small as 300 to as large as 2800 repeats

Blurring boundaries. Interviews with PGT couples about comprehensive chromosome screening

Objective: Comprehensive chromosome examination is a promising approach to Preimplantation Genetic Testing (PGT). Next to testing of specific chromosomes, such as in the case of reduced fertility due to chromosomal translocations, it allows testing of all chromosomes. Hence it potentially reduces the time to pregnancy and the risk of miscarriage. But comprehensive testing also introduces some ethical issues. For example, what is the role of the professional in the decision making regarding embryos with chromosomal abnormalities that are potentially viable? Which chromosomal abnormalities should be communicated to people undergoing fertility treatment? With this paper we wanted to explore the ethical issues related to comprehensive chromosome screening in Preimplantation Genetic Testing. Design: In order to explore these issues, we interviewed seven couples undergoing PGT for chromosomal translocations at the VUB University Hospital, Belgium. We presented them with three fictional cases: the transfer of an embryo with trisomy 21, of an embryo with a sex chromosome aneuploidy and of an embryo with a chromosomal microdeletion. Results: We found that opinions regarding the role of fertility professionals in deciding which embryos to transfer were mixed. Moreover, where to draw the line between healthy and unhealthy embryos was unclear. We also found that couples, although they thought that comprehensive chromosome testing had certain benefits, also considered the increased waiting time for transfer a heavy burden. Conclusions: In the light of comprehensive chromosome screening of embryos, persons undergoing fertility treatment may have views on the burdens and benefits of the techniques that are not analogous to the views of professionals

Analysis of the mitochondrial encoded subunits of complex 1 in 20 patients with a complex 1 deficiency

NADH-ubiquinone oxidoreductase or complex 1 deficiency is a frequently diagnosed enzyme defect of the oxidative phosphorylation (OXPHOS) system in humans. However, in many patients, with complex 1 deficiency and clinical symptoms suggestive of mitochondrial disease, often no genetic defect can be found after investigation of the most common mitochondrial DNA (mtDNA) mutations. In this study, 20 patients were selected with a biochemically documented complex 1 defect and no common mtDNA mutation. We used the Denaturing Gradient Get Electrophoresis (DGGE) method with primers encompassing all mitochondrial encoded fragments, to search in a systematic manner for mutations in the mitochondrial genome of complex 1. In our group of patients, we we re able to detect a total of 96 nucleotide changes. We were not able to find any disease causing mutation in the mitochondrial encoded subunits of complex 1. These results suggested that the complex 1 deficiency in this group of patients is most probably caused by a defect in one of the nuclear encoded structural genes of complex 1, or in one of the genes involved in proper assembly of the enzyme. (C) 2004 Published by Elsevier Ltd on behalf of European Paediatric Neurology Society