Demonstrating trustworthiness when collecting and sharing genomic data: public views across 22 countries

BACKGROUND

Public trust is central to the collection of genomic and health data and the sustainability of genomic research. To merit trust, those involved in collecting and sharing data need to demonstrate they are trustworthy. However, it is unclear what measures are most likely to demonstrate this.

METHODS

We analyse the 'Your DNA, Your Say' online survey of public perspectives on genomic data sharing including responses from 36,268 individuals across 22 low-, middle- and high-income countries, gathered in 15 languages. We examine how participants perceived the relative value of measures to demonstrate the trustworthiness of those using donated DNA and/or medical information. We examine between-country variation and present a consolidated ranking of measures.

RESULTS

Providing transparent information about who will benefit from data access was the most important measure to increase trust, endorsed by more than 50% of participants across 20 of 22 countries. It was followed by the option to withdraw data and transparency about who is using data and why. Variation was found for the importance of measures, notably information about sanctions for misuse of data-endorsed by 5% in India but almost 60% in Japan. A clustering analysis suggests alignment between some countries in the assessment of specific measures, such as the UK and Canada, Spain and Mexico and Portugal and Brazil. China and Russia are less closely aligned with other countries in terms of the value of the measures presented.

CONCLUSIONS

Our findings highlight the importance of transparency about data use and about the goals and potential benefits associated with data sharing, including to whom such benefits accrue. They show that members of the public value knowing what benefits accrue from the use of data. The study highlights the importance of locally sensitive measures to increase trust as genomic data sharing continues globally.

Global Public Perceptions of Genomic Data Sharing: What Shapes the Willingness to Donate DNA and Health Data?

Analyzing genomic data across populations is central to understanding the role of genetic factors in health and disease. Successful data sharing relies on public support, which requires attention to whether people around the world are willing to donate their data that are then subsequently shared with others for research. However, studies of such public perceptions are geographically limited and do not enable comparison. This paper presents results from a very large public survey on attitudes toward genomic data sharing. Data from 36,268 individuals across 22 countries (gathered in 15 languages) are presented. In general, publics across the world do not appear to be aware of, nor familiar with, the concepts of DNA, genetics, and genomics. Willingness to donate one's DNA and health data for research is relatively low, and trust in the process of data's being shared with multiple users (e.g., doctors, researchers, governments) is also low. Participants were most willing to donate DNA or health information for research when the recipient was specified as a medical doctor and least willing to donate when the recipient was a for-profit researcher. Those who were familiar with genetics and who were trusting of the users asking for data were more likely to be willing to donate. However, less than half of participants trusted more than one potential user of data, although this varied across countries. Genetic information was not uniformly seen as different from other forms of health information, but there was an association between seeing genetic information as special in some way compared to other health data and increased willingness to donate. The global perspective provided by our "Your DNA, Your Say" study is valuable for informing the development of international policy and practice for sharing genomic data. It highlights that the research community not only needs to be worthy of trust by the public, but also urgent steps need to be taken to authentically communicate why genomic research is necessary and how data donation, and subsequent sharing, is integral to this.

Willingness to donate genomic and other medical data: results from Germany

This paper reports findings from Germany-based participants in the “Your DNA, Your Say” study, a collaborative effort among researchers in more than 20 countries across the world to explore public attitudes, values and opinions towards willingness to donate genomic and other personal data for use by others. Based on a representative sample of German residents (n = 1506) who completed the German-language version of the survey, we found that views of genetic exceptionalism were less prevalent in the German-language arm of the study than in the English-language arm (43% versus 52%). Also, people’s willingness to make their data available for research was lower in the German than in the English-language samples of the study (56% versus 67%). In the German sample, those who were more familiar with genetics, and those holding views of genetic exceptionalism were more likely to be willing to donate data than others. We explain these findings with reference to the important role that the “right of informational self-determination” plays in German public discourse. Rather than being a particularly strict interpretation of privacy in the sense of a right to be left alone, the German understanding of informational self-determination bestows on each citizen the responsibility to carefully consider how their personal data should be used to protect important rights and to serve the public good.

'It's much more grey than black and white': clinical geneticists' views on the oversight of consumer genomics in Europe

Aim: Direct-to-consumer (DTC) genetic tests (GT) have created controversy regarding their risks and benefits. In view of recent regulatory developments, this article aims to explore the attitudes of European clinical geneticists toward the oversight of DTC GT. Materials & methods: Fifteen semi-structured interviews were performed with clinical geneticists based in ten European countries. The transcripts were thematically analysized in an iterative process. Results & conclusion: Respondents strongly supported quality standards for DTC GT equal to those applied within the healthcare setting. Despite participants unanimously considering the involvement of healthcare professionals to be important, mandatory medical supervision was controversial. In this regard, promoting education and truth-in-advertising was considered as being key in maintaining a balance between protecting consumers and promoting their autonomy.

Attitudes of publics who are unwilling to donate DNA data for research

With the use of genetic technology, researchers have the potential to inform medical diagnoses and treatment in actionable ways. Accurate variant interpretation is a necessary condition for the utility of genetic technology to unfold. This relies on the ability to access large genomic datasets so that comparisons can be made between variants of interest. This can only be successful if DNA and medical data are donated by large numbers of people to 'research', including clinical, non-profit and for-profit research initiatives, in order to be accessed by scientists and clinicians worldwide. The objective of the 'Your DNA, Your Say' global survey is to explore public attitudes, values and opinions towards willingness to donate and concerns regarding the donation of one's personal data for use by others. Using a representative sample of 8967 English-speaking publics from the UK, the USA, Canada and Australia, we explore the characteristics of people who are unwilling (n = 1426) to donate their DNA and medical information, together with an exploration of their reasons. Understanding this perspective is important for making sense of the interaction between science and society. It also helps to focus engagement initiatives on the issues of concern to some publics.

How do consent forms for diagnostic high-throughput sequencing address unsolicited and secondary findings? A content analysis

Whole exome and whole genome sequencing are increasingly being offered to patients in the clinical setting. Yet, the question of whether, and to what extent, unsolicited findings (UF) and/or secondary findings (SF) should be returned to patients remains open and little is known about how diagnostic consent forms address this issue. We systematically identified consent forms for diagnostic genomic sequencing online and used inductive content analysis to determine if and how they discuss reporting of UF and SF, and whether patients are given options regarding the return of these results. Fifty-four forms representing 38 laboratories/clinics were analyzed. A quarter of the forms did not mention UF or SF. Forms used a variety of terms to discuss UF and SF, sometimes using these interchangeably or incorrectly. Reporting policies for UF varied: 5 forms stated that UF will not be returned, 15 indicated UF may be returned, and 28 did not specify their policy. One-third indicated their laboratory returns SF. Addressing inconsistent terminology and providing sufficient information about UF/SF in consent forms will increase patient understanding and help ensure adequate informed consent.

'Your DNA, Your Say': global survey gathering attitudes toward genomics: design, delivery and methods

Our international study, 'Your DNA, Your Say', uses film and an online cross-sectional survey to gather public attitudes toward the donation, access and sharing of DNA information. We describe the methodological approach used to create an engaging and bespoke survey, suitable for translation into many different languages. We address some of the particular challenges in designing a survey on the subject of genomics. In order to understand the significance of a genomic result, researchers and clinicians alike use external databases containing DNA and medical information from thousands of people. We ask how publics would like their 'anonymous' data to be used (or not to be used) and whether they are concerned by the potential risks of reidentification; the results will be used to inform policy.

Human germline gene editing: Recommendations of ESHG and ESHRE

Technological developments in gene editing raise high expectations for clinical applications, first of all for somatic gene editing but in theory also for germline gene editing (GLGE). GLGE is currently not allowed in many countries. This makes clinical applications in these countries impossible now, even if GLGE would become safe and effective. What were the arguments behind this legislation, and are they still convincing? If a technique can help to avoid serious genetic disorders, in a safe and effective way, would this be a reason to reconsider earlier standpoints? The European Society of Human Reproduction and Embryology (ESHRE) and the European Society of Human Genetics (ESHG) together developed a Background document and Recommendations to inform and stimulate ongoing societal debates. After consulting its membership and experts, this final version of the Recommendations was endorsed by the Executive Committee and the Board of the respective Societies in May 2017. Taking account of ethical arguments, we argue that both basic and pre-clinical research regarding GLGE can be justified, with conditions. Furthermore, while clinical GLGE would be totally premature, it might become a responsible intervention in the future, but only after adequate pre-clinical research. Safety of the child and future generations is a major concern. Future discussions must also address priorities among reproductive and potential non-reproductive alternatives, such as PGD and somatic editing, if that would be safe and successful. The prohibition of human germline modification, however, needs renewed discussion among relevant stakeholders, including the general public and legislators.

Responsible innovation in human germline gene editing: Background document to the recommendations of ESHG and ESHRE

Technological developments in gene editing raise high expectations for clinical applications, including editing of the germline. The European Society of Human Reproduction and Embryology (ESHRE) and the European Society of Human Genetics (ESHG) together developed a Background document and Recommendations to inform and stimulate ongoing societal debates. This document provides the background to the Recommendations. Germline gene editing is currently not allowed in many countries. This makes clinical applications in these countries impossible now, even if germline gene editing would become safe and effective. What were the arguments behind this legislation, and are they still convincing? If a technique could help to avoid serious genetic disorders, in a safe and effective way, would this be a reason to reconsider earlier standpoints? This Background document summarizes the scientific developments and expectations regarding germline gene editing, legal regulations at the European level, and ethics for three different settings (basic research, preclinical research and clinical applications). In ethical terms, we argue that the deontological objections (e.g., gene editing goes against nature) do not seem convincing while consequentialist objections (e.g., safety for the children thus conceived and following generations) require research, not all of which is allowed in the current legal situation in European countries. Development of this Background document and Recommendations reflects the responsibility to help society understand and debate the full range of possible implications of the new technologies, and to contribute to regulations that are adapted to the dynamics of the field while taking account of ethical considerations and societal concerns.

Legislation of direct-to-consumer genetic testing in Europe: a fragmented regulatory landscape

Despite the increasing availability of direct-to-consumer (DTC) genetic testing, it is currently unclear how such services are regulated in Europe, due to the lack of EU or national legislation specifically addressing this issue. In this article, we provide an overview of laws that could potentially impact the regulation of DTC genetic testing in 26 European countries, namely Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, the Netherlands and the United Kingdom. Emphasis is placed on provisions relating to medical supervision, genetic counselling and informed consent. Our results indicate that currently there is a wide spectrum of laws regarding genetic testing in Europe. There are countries (e.g. France and Germany) which essentially ban DTC genetic testing, while in others (e.g. Luxembourg and Poland) DTC genetic testing may only be restricted by general laws, usually regarding health care services and patients' rights.

Human germline gene editing. Recommendations of ESHG and ESHRE

Technological developments in gene editing raise high expectations for clinical applications, first of all for somatic gene editing but in theory also for germline gene editing (GLGE). GLGE is currently not allowed in many countries. This makes clinical applications in these countries impossible now, even if GLGE would become safe and effective. What were the arguments behind this legislation, and are they still convincing? If a technique can help to avoid serious genetic disorders, in a safe and effective way, would this be a reason to reconsider earlier standpoints? The European Society of Human Reproduction and Embryology (ESHRE) and the European Society of Human Genetics (ESHG) together developed a Background document and Recommendations to inform and stimulate ongoing societal debates. After consulting its membership and experts, this final version of the Recommendations was endorsed by the Executive Committee and the Board of the respective Societies in May 2017. Taking account of ethical arguments, we argue that both basic and pre-clinical research regarding human GLGE can be justified, with conditions. Furthermore, while clinical GLGE would be totally premature, it might become a responsible intervention in the future, but only after adequate pre-clinical research. Safety of the child and future generations is a major concern. Future discussions must also address priorities among reproductive and potential non-reproductive alternatives, such as PGD and somatic editing, if that would be safe and successful. The prohibition of human germline modification, however, needs renewed discussion among relevant stakeholders, including the general public and legislators.

Responsible innovation in human germline gene editing. Background document to the recommendations of ESHG and ESHRE

Technological developments in gene editing raise high expectations for clinical applications, including editing of the germline. The European Society of Human Reproduction and Embryology (ESHRE) and the European Society of Human Genetics (ESHG) together developed a Background document and Recommendations to inform and stimulate ongoing societal debates. This document provides the background to the Recommendations. Germline gene editing is currently not allowed in many countries. This makes clinical applications in these countries impossible now, even if germline gene editing would become safe and effective. What were the arguments behind this legislation, and are they still convincing? If a technique could help to avoid serious genetic disorders, in a safe and effective way, would this be a reason to reconsider earlier standpoints? This Background document summarizes the scientific developments and expectations regarding germline gene editing, legal regulations at the European level, and ethics for three different settings (basic research, pre-clinical research and clinical applications). In ethical terms, we argue that the deontological objections (e.g. gene editing goes against nature) do not seem convincing while consequentialist objections (e.g. safety for the children thus conceived and following generations) require research, not all of which is allowed in the current legal situation in European countries. Development of this Background document and Recommendations reflects the responsibility to help society understand and debate the full range of possible implications of the new technologies, and to contribute to regulations that are adapted to the dynamics of the field while taking account of ethical considerations and societal concerns.

One small edit for humans, one giant edit for humankind? Points and questions to consider for a responsible way forward for gene editing in humans

Gene editing, which allows for specific location(s) in the genome to be targeted and altered by deleting, adding or substituting nucleotides, is currently the subject of important academic and policy discussions. With the advent of efficient tools, such as CRISPR-Cas9, the plausibility of using gene editing safely in humans for either somatic or germ line gene editing is being considered seriously. Beyond safety issues, somatic gene editing in humans does raise ethical, legal and social issues (ELSI), however, it is suggested to be less challenging to existing ethical and legal frameworks; indeed somatic gene editing is already applied in (pre-) clinical trials. In contrast, the notion of altering the germ line or embryo such that alterations could be heritable in humans raises a large number of ELSI; it is currently debated whether it should even be allowed in the context of basic research. Even greater ELSI debates address the potential use of germ line or embryo gene editing for clinical purposes, which, at the moment is not being conducted and is prohibited in several jurisdictions. In the context of these ongoing debates surrounding gene editing, we present herein guidance to further discussion and investigation by highlighting three crucial areas that merit the most attention, time and resources at this stage in the responsible development and use of gene editing technologies: (1) conducting careful scientific research and disseminating results to build a solid evidence base; (2) conducting ethical, legal and social issues research; and (3) conducting meaningful stakeholder engagement, education and dialogue.

Responsible implementation of expanded carrier screening

This corrects the article DOI: 10.1038/ejhg.2015.271.

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.

Current developments in the regulation of direct-to-consumer genetic testing in Europe

Over the past years, direct-to-consumer (DTC) genetic testing has provoked controversy regarding its still questionable risks and benefits. The safety and performance of such devices, when entering the European market, are currently regulated by the Directive 98/79 EC of the European Parliament and of the Council on in vitro diagnostic medical devices. In September 2012, a new Regulation was proposed to replace this Directive, and the legislative process is still ongoing. This article presents the main points of the European Commission’s proposal for the new Regulation and the subsequent amendments voted by the European Parliament, aiming to evaluate the potential contribution of the proposal for a more effective regulation of DTC genetic testing in Europe. In this regard, the proposal seems to enhance the current regulatory framework by further elucidating the scope of the Regulation and by establishing a risk-based classification system that guarantees increased pre-market scrutiny of the tests. Furthermore, the proposal attempts to establish higher safety and performance requirements and to enhance transparency. In addition, the European Parliament introduced amendments according to which appropriate genetic counselling is required in the context of genetic tests, and such tests are classified as prescription only, banning, at the same time, their DTC advertising. These developments have already provoked controversy among stakeholders and, if eventually adopted, they may lead to a radical change in the European DTC genetic testing landscape. In this light, the political decisions that will be taken imminently will be determinant.

Non-invasive prenatal testing for aneuploidy and beyond: challenges of responsible innovation in prenatal screening

This paper contains a joint ESHG/ASHG position document with recommendations regarding responsible innovation in prenatal screening with non-invasive prenatal testing (NIPT). By virtue of its greater accuracy and safety with respect to prenatal screening for common autosomal aneuploidies, NIPT has the potential of helping the practice better achieve its aim of facilitating autonomous reproductive choices, provided that balanced pretest information and non-directive counseling are available as part of the screening offer. Depending on the health-care setting, different scenarios for NIPT-based screening for common autosomal aneuploidies are possible. The trade-offs involved in these scenarios should be assessed in light of the aim of screening, the balance of benefits and burdens for pregnant women and their partners and considerations of cost-effectiveness and justice. With improving screening technologies and decreasing costs of sequencing and analysis, it will become possible in the near future to significantly expand the scope of prenatal screening beyond common autosomal aneuploidies. Commercial providers have already begun expanding their tests to include sex-chromosomal abnormalities and microdeletions. However, multiple false positives may undermine the main achievement of NIPT in the context of prenatal screening: the significant reduction of the invasive testing rate. This document argues for a cautious expansion of the scope of prenatal screening to serious congenital and childhood disorders, only following sound validation studies and a comprehensive evaluation of all relevant aspects. A further core message of this document is that in countries where prenatal screening is offered as a public health programme, governments and public health authorities should adopt an active role to ensure the responsible innovation of prenatal screening on the basis of ethical principles. Crucial elements are the quality of the screening process as a whole (including non-laboratory aspects such as information and counseling), education of professionals, systematic evaluation of all aspects of prenatal screening, development of better evaluation tools in the light of the aim of the practice, accountability to all stakeholders including children born from screened pregnancies and persons living with the conditions targeted in prenatal screening and promotion of equity of access.

“It’s our DNA, we deserve the right to test!” A content analysis of a petition for the right to access direct-to-consumer genetic testing

Aims: Various companies are currently advertising or selling genetic tests over the internet using a model of provision referred to as ‘direct-to-consumer’ (DTC). This commercial offer of DTC genetic testing (GT) has fueled a number of scientific, ethical and policy debates. To date there have been few studies published regarding the users’ perspective. This study aimed to obtain information regarding the issues raised by individuals who signed a petition in support of DTC GT and the ‘unrestricted’ access to their genetic information. Materials & methods: We conducted qualitative content analysis of comments written by individuals who signed a public online petition initiated by DIYgenomics (CA, USA) to support “personal access to genetic information”. Results: Of the 523 individuals who signed the petition sponsored by DIYgenomics, 247 individuals also wrote individual comments. A content analysis of these comments reveals that petitioners raised six main issues in support of unrestricted access to DTC GT: that their ownership of their DNA should allow them to have unrestricted access to their genomic information; that they should have the right to their genomic information; that the government has no place in (further) regulating DTC GT; that healthcare professionals should not be placed as intermediaries when purchasing DTC GT services; that many petioners who had already obtained DTC GT had positive experiences with this model of provision; and that genealogy or ancestry DNA testing is one of the main activities petitioners wish to have ‘unrestricted’ or ‘direct’ access. Conclusion: These results give insight into why individuals may support unrestricted access to their genomic information and confirm some of the motivations of users for purchasing DTC GT. Our analysis also brings to the forefront themes that have been raised less often in empirical studies involving motivations to purchase DTC GT services; these include the strongly held beliefs of some petitioners that, since they own their DNA, they should have the right to access the information without (further) government control or physician involvement. Interestingly, the comments left by petitioners also reveal a certain distrust of governmental agencies and healthcare professionals. This urges us to further study the public’s views of these services and the potential impact of these views in order to responsibly address the ongoing debate on DTC GT.

Informed consent in the context of pharmacogenomic research: ethical considerations

Although the scientific research surrounding pharmacogenomics (PGx) has been relatively plentiful, the ethical research concerning this discipline has developed rather conservatively. Following investigation of the ethical, legal and social issues (ELSI) of PGx research, as well as consulting with key stakeholders, we identified six outstanding ethical issues raised by the informed consent process in PGx research: (1) scope of consent; (2) consent to 'add-on' studies; (3) protection of personal information; (4) commercialization; (5) data sharing; and (6) potential risks stemming from population-based research. In discussing these six areas as well as offering specific considerations, this article offers a solid base from which future practical guidelines for informed consent in PGx research can be constructed. As such, this effort works toward filling the ELSI gap and provides ethical support to the numerous PGx projects undertaken by researchers every year.

Preconceptional genetic carrier testing and the commercial offer directly-to-consumers

Recently, a number of commercial companies are offering preconceptional carrier tests directly-to-consumers. This offer raises a number of concerns and issues above and beyond those encountered with preconceptional tests offered within the traditional health care setting. In order to bring some of these issues to light and to initiate dialogue on this topic, this article discusses the following issues: the current offer of preconceptional carrier tests (until the end of 2010) through online commercial companies; the implications for the informed consent procedure and the need for good information; the need for medical supervision and follow-up; and the appropriate use of existing resources. The article concludes with some reflections about the potential sustainability of the offer of preconceptional carrier tests directly-to-consumers.

Blurring lines. The research activities of direct-to-consumer genetic testing companies raise questions about consumers as research subjects

Companies that offer direct-to-consumer genetic testing and conduct research are blurring the line between customers and research subjects. Should these companies adhere to the same ethical regulations as academic researchers?

The research activities of direct-to-consumer genetic testing companies raise questions about consumers as research subjects

Health-related direct-to-consumer genetic testing: a review of companies' policies with regard to genetic testing in minors

More and more companies are advertising and selling genetic tests directly to consumers. Considering the ethical, legal, and psychological concerns surrounding genetic testing in minors, a study of companies' websites was performed in order to describe and analyze their policies with respect to this issue. Of the 29 companies analyzed, 13 did not provide any information about this matter, eight companies allowed genetic testing upon parental request, four companies stated that their website is not directed to children under 18 years, and four companies suggested that in order to be tested, applicants should have reached the age of legal majority. If private companies offer genetic tests which are also offered in a clinical setting, can they be expected to adhere to the existing clinical guidelines with regard to these tests? If so, a certain ambiguity exists. Many companies are emphasizing in their disclaimers that their services are not medical services and should not be used as a basis for making medical decisions. Nonetheless, it remains debatable whether genetic testing in minors would be appropriate in this context. In line with the Advisory Committee on Genetic Testing, the Human Genetics Commission addressed the problem of non-consensual testing and recommended not to supply genetic testing services directly to those under the age of 16 or to those not able to make a competent decision regarding testing.

Letter to the Editor

In response to: Howard HC, Borry P: Direct-to-consumer genetic testing: more questions than benefits? Personalized Med. 5(4), 317-320 (2008).

tAnGo: a randomised phase III trial of gemcitabine in paclitaxel-containing, epirubicin/cyclophosphamide-based, adjuvant chemotherapy for early breast cancer: a prospective pulmonary, cardiac and hepatic function evaluation

tAnGo is a large randomised trial assessing the addition of gemcitabine(G) to paclitaxel(T), following epirubicin(E) and cyclophosphamide(C) in women with invasive higher risk early breast cancer. To assess the safety and tolerability of adding G, a detailed safety substudy was undertaken. A total of 135 patients had cardiac, pulmonary and hepatic function assessed at (i) randomisation, (ii) mid-chemotherapy, (iii) immediately post-chemotherapy and (iv) 6 months post-chemotherapy. Skin toxicity was assessed during radiotherapy. No differences were detected in FEV₁ or FVC levels between treatment arms or time points. Diffusion capacity (TL_CO) reduced during treatment (P<0.0001), with a significantly lower drop in EC-GT patients (P=0.02). Most of the reduction occurred during EC and recovered by 6-months post treatment. There was no difference in cardiac function between treatment arms. Only 11 patients had echocardiography/MUGA results change from normal to abnormal during treatment, with only five having LVEF<50%. Transient transaminitis occurred in both treatment arms with significantly more in EC-GT patients post-chemotherapy (AST P=0.03, ALT P=0.003), although the majority was low grade. There was no correlation between transaminitis and other toxicities. Both treatment regimens reported temporary reductions in pulmonary functions and transient transaminitis levels. Despite these being greater with EC-GT, both regimens appear well tolerated.

Hereditary motor and sensory neuropathy with agenesis of the corpus callosum

Hereditary motor and sensory neuropathy associated with agenesis of the corpus callosum (OMIM 218000) is an autosomal recessive disease of early onset characterized by a delay in developmental milestones, a severe sensory-motor polyneuropathy with areflexia, a variable degree of agenesis of the corpus callosum, amyotrophy, hypotonia, and cognitive impairment. Although this disorder has rarely been reported worldwide, it has a high prevalence in the Saguenay-Lac-St-Jean region of the province of Quebec (Canada) predominantly because of a founder effect. The gene defect responsible for this disorder recently has been identified, and it is a protein-truncating mutation in the SLC12A6 gene, which codes for a cotransporter protein known as KCC3. Herein, we provide the first extensive review of this disorder, covering epidemiological, clinical, and molecular genetic studies.

Agonist binding to peptide hormone receptors

A fundamental issue in molecular pharmacology is to define how agonist-receptor interaction differs from that of antagonist-receptor interaction. The V(1a) vasopressin receptor (V(1a)R) is a member of a family of related G-protein-coupled receptors (GPCRs) that are activated by vasopressin, oxytocin (OT) and related peptides. A segment of the N-terminus that was required for agonist binding, but not antagonist binding, was identified by characterizing truncated V(1a)R constructs. Site-directed mutagenesis revealed that a single residue (Arg(46)) was critical for agonist binding and receptor activation. The N-terminus of the related OT receptor (OTR) could recover agonist binding in a chimaeric OTR(N)-V(1a)R construct. Furthermore, Arg(34) of the human OTR, which corresponds to Arg(46) of the rat V(1a)R, provided agonist-specific binding epitopes in the OTR, indicating a conserved function of this locus throughout this GPCR subfamily. Mutation of Arg(46) revealed that high-affinity agonist binding had an absolute requirement for arginine at this position.

The K-Cl cotransporter KCC3 is mutant in a severe peripheral neuropathy associated with agenesis of the corpus callosum

Peripheral neuropathy associated with agenesis of the corpus callosum (ACCPN) is a severe sensorimotor neuropathy associated with mental retardation, dysmorphic features and complete or partial agenesis of the corpus callosum. ACCPN is transmitted in an autosomal recessive fashion and is found at a high frequency in the province of Quebec, Canada. ACCPN has been previously mapped to chromosome 15q. The gene SLC12A6 (solute carrier family 12, member 6), which encodes the K+-Cl- transporter KCC3 and maps within the ACCPN candidate region, was screened for mutations in individuals with ACCPN. Four distinct protein-truncating mutations were found: two in the French Canadian population and two in non-French Canadian families. The functional consequence of the predominant French Canadian mutation (2436delG, Thr813fsX813) was examined by heterologous expression of wildtype and mutant KCC3 in Xenopus laevis oocytes; the truncated mutant is appropriately glycosylated and expressed at the cellular membrane, where it is non-functional. Mice generated with a targeted deletion of Slc12a6 have a locomotor deficit, peripheral neuropathy and a sensorimotor gating deficit, similar to the human disease. Our findings identify mutations in SLC12A6 as the genetic lesion underlying ACCPN and suggest a critical role for SLC12A6 in the development and maintenance of the nervous system.

Fine mapping the candidate region for peripheral neuropathy with or without agenesis of the corpus callosum in the French Canadian population

Peripheral neuropathy with or without agenesis of the corpus callosum (ACCPN [MIM 2180000]) is an autosomal recessive disease characterised by progressive sensorimotor neuropathy, mental retardation, dysmorphic features and complete or partial agenesis of the corpus callosum. The ACCPN gene was mapped in 1996 to a 4 cM region on chromosome 15. We have since collected additional French Canadian (FC) families and typed a total of 11 polymorphic markers spanning approximately 18 cM on chromosome 15. Through the use of haplotype analysis we have confirmed the presence of a founder haplotype in the FC population, and identified critical recombinants which reduce the ACCPN candidate interval to a approximately 2 cM or 1000 Kb region flanked by markers D15S1040 and ACTC. Linkage disequilibrium analysis supports the haplotype data, and suggests that the ACCPN gene lies nearest to marker D15S1232.

Identification of an extracellular segment of the oxytocin receptor providing agonist-specific binding epitopes

The effects of the peptide hormone oxytocin are mediated by oxytocin receptors (OTRs) expressed by the target tissue. The OTR is a member of the large family of G-protein-coupled receptors. Defining differences between the interaction of agonists and antagonists with the OTR at the molecular level is of fundamental importance, and is addressed in this study. Using truncated and chimaeric receptor constructs, we establish that a small 12-residue segment in the distal portion of the N-terminus of the human OTR provides important epitopes which are required for agonist binding. In contrast, this segment does not contribute to the binding site for antagonists, whether peptide or non-peptide. It does, however, have a role in agonist-induced OTR signalling. Oxytocin is also an agonist at the vasopressin V(1a) receptor (V(1a)R). A chimaeric receptor (V(1a)R(N)-OTR) was engineered in which the N-terminus of the OTR was substituted by the corresponding, but unrelated, sequence from the N-terminus of the V(1a)R. We show that the V(1a)R N-terminus present in V(1a)R(N)-OTR fully restored both agonist binding and intracellular signalling to a dysfunctional truncated OTR construct. The N-terminal segment does not, however, contribute to receptor-selective agonism between the OTR and the V(1a)R. Our data establish a key role for the distal N-terminus of the OTR in providing agonist-specific binding epitopes.