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

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? 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. 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. 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. We conducted an expert panel in October 2011 with seven PGD pioneers from Belgium, The Netherlands, Germany and the UK. 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. 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. 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. 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. N/A

Is germ-line genome modification ethically justified?

As the normative objections to (human) germline genome editing cannot convincingly justify a categorical prohibition of such editing, its present prohibition should be replaced by a strict regulation, i.e. a conditional allowance. If safe and effective, germline genome editing may become a useful reproductive option.</p

Making embryos for research:First prohibited, now allowed?

The Dutch Embryos Act (2000) contains a temporary ban on the creation of embryos for research, meaning that, at present, only research using "spare" IVF embryos is allowed. Recently, the government has announced a plan to lift this ban. This is in line with the original intention of the Act, which already contains conditions for research with specially created embryos that will come into force after the lifting of the ban, including the restriction that the research must be expected to yield new insights in the domains of infertility, assisted reproduction, hereditary or congenital disorders, or transplantation medicine. The government plans announced allow research only in the first three of these domains, adding the further criterion that the research must be 'directly relevant for clinical application'. According to the government, the reason for these additional restrictions was the need to protect 'human dignity'. The authors of this paper are not convinced

Making embryos for research:First prohibited, now allowed?

The Dutch Embryos Act (2000) contains a temporary ban on the creation of embryos for research, meaning that, at present, only research using "spare" IVF embryos is allowed. Recently, the government has announced a plan to lift this ban. This is in line with the original intention of the Act, which already contains conditions for research with specially created embryos that will come into force after the lifting of the ban, including the restriction that the research must be expected to yield new insights in the domains of infertility, assisted reproduction, hereditary or congenital disorders, or transplantation medicine. The government plans announced allow research only in the first three of these domains, adding the further criterion that the research must be 'directly relevant for clinical application'. According to the government, the reason for these additional restrictions was the need to protect 'human dignity'. The authors of this paper are not convinced

Risk Assessment for Huntington's Disease for (Future) Offspring Requires Offering Preconceptional CAG Analysis to Both Partners

Amongst the main reasons people at risk for Huntington's disease (HD) have for undergoing predictive genetic testing are planning a family and prevention of passing on an expanded CAG-repeat to future offspring. After having received an unfavourable test result, a couple may consider prenatal testing in the foetus or preimplantation genetic diagnostic testing (PGD) in embryos. Testing of the foetus or embryos is possible by means of direct testing of the expanded repeat. Optimal reliability in testing the foetus or embryos requires the establishment of the origin of the repeats of both parents in the foetus. For PGD the analysis is combined with or sometimes solely based on identification of the at-risk haplotype in the embryo. This policy implies that in the context of direct testing, the healthy partner's CAG repeat lengths in the HD gene are also tested, but with the expectation that the repeat lengths of the partner are within the normal range, with the proviso that the partner's pedigree is free of clinically confirmed HD. However, recent studies have shown that the expanded repeat has been observed more often in the general population than previously estimated. Moreover, we have unexpectedly observed an expanded repeat in the non-HD partner in four cases which had far-reaching consequences. Hence, we propose that in the context of reproductive genetic counselling, prior to a planned pregnancy, and irrespective of the outcome of the predictive test in the HD-partner, the non-HD partner should also be given the option of being tested on the expanded allele. International recommendations for predictive testing for HD should be adjusted.Genetics of disease, diagnosis and treatmen

Reply to Oliver W Quarrell et al.:"Letter in response to Tibben et al., Risk Assessment for Huntington's Disease for (Future) Offspring Requires Offering Preconceptional CAG Analysis to Both Partners"

Genetics of disease, diagnosis and treatmen

Views of patients and parents of children with genetic disorders on population-based expanded carrier screening

Objective Faster and cheaper next generation sequencing technologies have enabled expansion of carrier screening for recessive disorders, potentially facilitating population-based implementation regardless of ancestry or family history. Little is known, however, about the attitudes regarding population-based carrier screening among families with genetic disorders. This study assessed views among parents and patients with a recessive disorder and parents of children with Down syndrome (DS) on expanded carrier screening (ECS). Method In total, 85 patients with various recessive disorders, 110 parents of a child with a recessive disorder and 89 parents of a child with DS participated in an online survey in the Netherlands. Severity of recessive disorders was classified as mild/moderate or severe/profound. Results The majority of the (parents of) patients with a recessive disorder had a positive attitude towards population-based ECS, including screening for their own or their child's disorder. DS parents were significantly less positive towards ECS. Subgroup analyses showed that the severity of the disorder, rather than being a patient or parent, influences the attitudes, beliefs and intention to participate in ECS. Conclusion Our findings have important implications for future implementation initiatives as they demonstrate the different perspectives from people with experiential knowledge with genetic disorders

Responsible implementation of expanded carrier screening.

This document of the European Society of Human Genetics contains recommendations regarding responsible implementation of expanded carrier screening. Carrier screening is defined here as the detection of carrier status of recessive diseases in couples or persons who do not have an a priori increased risk of being a carrier based on their or their partners' personal or family history. Expanded carrier screening offers carrier screening for multiple autosomal and X-linked recessive disorders, facilitated by new genetic testing technologies, and allows testing of individuals regardless of ancestry or geographic origin. Carrier screening aims to identify couples who have an increased risk of having an affected child in order to facilitate informed reproductive decision making. In previous decades, carrier screening was typically performed for one or few relatively common recessive disorders associated with significant morbidity, reduced life-expectancy and often because of a considerable higher carrier frequency in a specific population for certain diseases. New genetic testing technologies enable the expansion of screening to multiple conditions, genes or sequence variants. Expanded carrier screening panels that have been introduced to date have been advertised and offered to health care professionals and the public on a commercial basis. This document discusses the challenges that expanded carrier screening might pose in the context of the lessons learnt from decades of population-based carrier screening and in the context of existing screening criteria. It aims to contribute to the public and professional discussion and to arrive at better clinical and laboratory practice guidelines.European Journal of Human Genetics advance online publication, 16 March 2016; doi:10.1038/ejhg.2015.271