The authors find it more useful to payattention to relationships than to boundaries.By focusing attention on bounded, individualpsychological issues, the metaphor ofboundaries can distract helping professionalsfrom thinking about inequities of power. Itoversimplifies a complex issue, inviting us toignore discourses around gender, race, class,culture, and the like that support injustice,abuse, and exploitation. Making boundaries acentral metaphor for ethical practice can keepus from critically examining the effects ofdistance, withdrawal, and non-participation.The authors describe how it is possible toexamine the practical, moral, and ethicaleffects (...) of our participation in relationshipsby focusing on just relationships rather thanon boundaries. They give illustrations andclinical examples of relationally-focusedethical practices that derive from a narrativeapproach to therapy. (shrink)

Informed by a search of the literature about the usage of genetic testing information (GTI) by insurance companies, this paper presents a practical ethical analysis of several distinct public policy options that might be used to govern or constrain GTI usage by insurance providers. As medical research advances and the extension to the Human Genome Project (2016, https://en.wikipedia.org/wiki/human_genome_project_-_write) moves to its fullness over the next decade, such research efforts will allow the full synthesis of human DNA to be connected to (...) predictive health dispositions. As testing costs fall, there will be ever more pressure for citizens to disclose GTI. Genetic testing information is integral to future medical care because it can be used to better assess individually tailored medical therapies as well as to allow a more informed risk analysis by the insurance industry, which in some countries such as the USA underwrites a majority of citizen medical expenses. As discussed in this examination, the revelation of people’s uniquely personal GTI to insurers has enormous societal implications. The major contribution of the paper is to offer policy makers and concerned citizens a nuanced articulation of the basic options to regulate GTI, with a special consideration for ethical fairness and equity. As genetic-based medicine blossoms and pressures to reduce healthcare costs increase, there will be an ever greater impetus for countries to revisit their genetic testing policies. Organizations and policy makers striving to create GTI oversights perceived to be both “fair and effective” need to be aware of the ethical perspectives discussed in this paper. (shrink)

The Streptococcus pyogenes CRISPR‐Cas system has gained widespread application as a genome editing and gene regulation tool as simultaneous cellular delivery of the Cas9 protein and guide RNAs enables recognition of specific DNA sequences. The recent discovery that Cas9 can also bind and cleave RNA in an RNA‐programmable manner indicates the potential utility of this system as a universal nucleic acid‐recognition technology. RNA‐targeted Cas9 (RCas9) could allow identification and manipulation of RNA substrates in live cells, empowering the study of (...) cellular gene expression, and could ultimately spawn patient‐ and disease‐specific diagnostic and therapeutic tools. Here we describe the development of RCas9 and compare it to previous methods for RNA targeting, including engineered RNA‐binding proteins and other types of CRISPR‐Cas systems. We discuss potential uses ranging from live imaging of transcriptional dynamics to patient‐specific therapies and applications in synthetic biology. (shrink)

The article investigates the validity of two different versions of the slippery slope argument construed in relation to human gene therapy: the empirical and the conceptual argument. The empirical version holds that our accepting somatic cell therapy will eventually cause our accepting eugenic medical goals. The conceptual version holds that we are logically committed to accepting such goals once we have accepted somatic cell therapy. It is argued that neither the empirical nor the conceptual version of (...) the argument can provide a conclusive moral reason for banning somatic cell therapy. According to a third interpretation, referred to as the arbitrary result argument, the many apparent similarities between somatic cell therapy and eugenic-based human genetic engineering drive us to make principled choices concerning what differences and similarities between the two practices should be regarded as morally (ir)relevant. Decisions of this kind are likely to have unpredictable moral consequences. Thus formulated, the slippery slope argument has much plausibility. One objects to somatic cell therapy not so much because of what is at the bottom of the slope on which it lies, but because it is on a slope of which one does not know what is at the bottom. While the arbitrary result argument does not provide a conclusive reason for prohibiting human gene therapy, it reminds of a very important thing: when making bioethical decisions, we should be as specific and as consistent as possible about our basic moral and medical concepts. (shrink)

To discern the ethical issues involved incurrent gene therapy research, to explore theproblems inherent in possible future genetherapies, and to encourage debate within thescientific community about ethical questionsrelevant to both, we surveyed American Societyof Human Genetics scientists who engage inhuman genetics research. This study of theopinions of U.S. scientific experts about theethical issues discussed in the literature ongene therapy contributes systematic data on theattitudes of those working in the field as wellas elaborative comments. Our survey finds thatrespondents (...) are highly supportive of thepotential use of somatic cell gene therapy tocure serious diseases in adults and children aswell as prospective offspring. A clearmajority, however, believe that using suchgenetic techniques for enhancement purposes isunacceptable. Delineating the line betweendisease/disorder and improvement/enhancementposes a problem not easily resolved and oneconducive to the growth of slippery-slopeapprehensions. The majority of respondents alsoadvocate germ-line therapy, in theory at least,and under similar restrictions, but theyrecognize the roadblock that the existence ofunanticipated negative consequences currentlypresents. Another complex matter involvestrying to determine appropriate reasons forchoosing target diseases for research, forwhich the dichotomy between rare single-geneand common multifactorial diseases reveals anongoing dilemma. (shrink)

This article challenges the view of disability presented by Harris in his article, “Is gene therapy a form of eugenics?”1 It is argued that his definition of disability rests on an individual model of disability, where disability is regarded as a product of biological determinism or “personal tragedy” in the individual. Within disability theory this view is often called “the medical model” and it has been criticised for not being able to deal with the term “disability”, but only (...) with impairment. The individual model of disability presupposes a necessary causal link between a certain condition in the individual and disablement. The shortcomings of such a view of disability are stated and it is argued that in order to have an adequate ethical discourse on gene therapy perspectives from disability research need to be taken into consideration. (shrink)

Despite widespread agreement that it would be ethical to use somatic cell gene therapy to correct serious diseases, there is still uneasiness on the part of the public about this procedure. The basis for this concern lies less with the procedure's clinical risks than with fear that genetic engineering could lead to changes in human nature. Legitimate concerns about the potential for misuse of gene transfer technology justify drawing a moral line that includes corrective germline therapy (...) but excludes enhancement interventions in both somatic and germline contexts. Keywords: somatic cell, germ line, genetic diseases, genetic engineering, humanness, enhancement, eugenics CiteULike Connotea Del.icio.us What's this? (shrink)

The strength of a slippery slope argument is a matter of some dispute. Some see it as a reasonable argument pointing out what probably or inevitably follows from adopting some practice, others see it as essentially a fallacious argument. However, there seems to be a tendency emerging to say that in many cases, the argument is not actually fallacious, although it may be unsubstantiated. I shall not try to settle this general discussion, but merely seek to assess the strength of (...) the slippery slope argument applied to human gene therapy. The structure of my argument will be the following. First, I shall distinguish between three different versions of the slippery slope argument; two logical versions and an empirical one. Next, I will address human gene therapy in terms of each of the three versions, partly relying on slippery slope arguments against this practice that have already surfaced in the literature. I shall argue that neither version pulls through. The logical versions fail primarily because relevant distinctions can be made between different uses of gene therapy, contrary to what the proponents of the arguments claim. The empirical version fails because there seems to be no evidence supporting the claim that we shall in fact slide down the slope if we engage in gene therapy, and because if we accepted the conclusion that we should not allow gene therapy on the basis of the empirical argument, we should have to make very far-reaching and undesirable modifications in health care in general, in order to be consistent. Or at least so I shall argue. (shrink)

Any suggestion of altering the genetic makeup of human beings through gene therapy is quite likely to provoke a response involving some reference to a 'slippery slope'. In this article the author examines the topography of two different types of slippery slope argument, the logical slippery slope and the rhetorical slippery slope argument. The logical form of the argument suggests that if we permit somatic cell gene therapy then we are committed to accepting germ line (...) class='Hi'>gene therapy in the future because there is no logically sustainable distinction between them. The rhetorical form posits that allowing somatic cell therapy now will be taking the first step on a slippery slope which will ultimately lead to the type of genocide perpetrated by the Nazis. The author tests the validity of these lines of argument against the facts of human gene therapy and concludes that because of their dependence on probabilities that cannot be empirically proven they should be largely disregarded in the much more important debate on moral line-drawing in gene therapy. (shrink)

types of application of genetic engineering for the insertion of genes into humans. The scientific requirements and the ethical issues associated with each type are discussed. Somatic cell gene therapy is technically the simplest and ethically the least controversial. The first clinical trials will probably be undertaken within the next year. Germ line gene therapy will require major advances in our present knowledge and it raises ethical issues that are now being debated. In order to provide (...) guidelines for determining when germ line gene therapy would be ethical, the author presents three criteria which should be satisfied prior to the time that a clinical protocol is attempted in humans. Enhancement genetic engineering presents significant, and troubling, ethical concerns. Except where this type of therapy can be justified on the grounds of preventive medicine, enhancement engineering should not be performed. The fourth type, eugenic genetic engineering, is impossible at present and will probably remain so for the foreseeable future, despite the widespread media attention it has received. Keywords: genetic engineering, somatic cells, germ cells, enhancement, eugenics, humanhood CiteULike Connotea Del.icio.us What's this? (shrink)

It may be unethical to deny children with cystic fibrosis access to ethically approved clinical trials from which they might benefitDespite advances in nutritional management, aggressive antibiotic usage, and physiotherapy, cystic fibrosis remains a life limiting illness with high morbidity that imposes considerable burdens on children and families.1 Although survival to 40 years is predicted for children born in 1990s, the median age of death in 2003 was 24.2 years .The pathophysiological features of CF are produced by a defective (...) class='Hi'>gene on chromosome 7, resulting in the defective production of a protein that regulates cellular ion transport. Defective ion transport is thought to lead to increased mucus viscosity , with poor airway clearance, recurrent bacterial infection, lung damage, and death.Gene therapy , the insertion of a normally functioning gene into deficient host cells using a suitable vector, is a potential treatment or cure for diseases produced by single gene defects—for example, CF. Gene therapy does, however, have potential or actual risks, leading many to suggest that evidence of efficacy in adults should be demonstrated before trials are conducted in children. Many serious diseases in adults such as CF have their onset in childhood. If early treatment provides greater hopes of benefit, children may be more appropriate targets for GT in CF than adults. It may be unethical to deny them access to properly constructed, ethically approved clinical trials from which they might benefit.Since research in children should be scientifically valid, in the child’s best interests, and the subject of valid consent, this article will consider these parameters in relation to trials of GT in children with CF. Because of the importance of consumer participation in the design of research we present the results of a questionnaire about GT trials delivered …. (shrink)

Oversight of human gene transfer research presents an important model with potential application to oversight of nanobiology research on human participants. Gene therapy oversight adds centralized federal review at the National Institutes of Health's Office of Biotechnology Activities and its Recombinant DNA Advisory Committee to standard oversight of human subjects research at the researcher's institution and at the federal level by the Office for Human Research Protections. The Food and Drug Administration's Center for Biologics Evaluation and Research (...) oversees human gene transfer research in parallel, including approval of protocols and regulation of products. This article traces the evolution of this dual oversight system; describes how the system is already addressing nanobiotechnology in gene transfer: evaluates gene therapy oversight based on public opinion, the literature, and preliminary expert elicitation; and offers lessons of the gene therapy oversight experience for oversight of nanobiotechnology. (shrink)

As a philosopher interested in biomedical ethics, I find recent advances in genetic technologies both fascinating and frightening. Future technologies for genetic therapies and elimination of clearly deleterious genes offer us the ability to get rid of the cause of much human suffering, seemingly at its physiological root. But memories of past eugenics programs gone horribly awry must make cautious our initial optimism for these generally well-intentioned programs. Most often the scientist proceeds in research with the best of intentions, but (...) that does not make all scientific investigation worth pursuing. (shrink)

Gene therapy and gene editing are revolutionising the treatment of genetic diseases, most notably haematological disorders. This paper evaluates the use of both techniques in hereditary blood disorders. Many studies have been conducted in this field, especially with gene therapy, with very promising results in diseases such as haemophilia, certain haemoglobinopathies and Fanconi anaemia. The application of these techniques in clinical practice and the foreseeable development of these approaches in the coming years suggest that it (...) might be useful to evaluate the results achieved thus far. It is also essential to reflect on the possible bioethical concerns raised by the use of both techniques, especially in terms of safety issues for patients, potential side effects, treatment duration, accessibility and cost of treatment, and the heritability of genetic changes produced if germline cells are used. (shrink)

Gene therapy approaches have great promise in the treatment of neurodegenerative disorders and malignant brain tumors. Neuwelt et al. review available viral-mediated gene therapy methods and their blood-brain-barrier (BBB) disruption delivery technique, briefly mentioning nonviral mediated gene therapy methods. This commentary discussed the BBB disruption delivery technique, viral and nonviral mediated gene therapy approaches to Parkinson's disease, and the potential use of antisense oligo to suppress malignant brain tumors.

In lieu of an abstract, here is a brief excerpt of the content:Human Gene TherapyMary Carrington Coutts (bio)On September 14, 1990, researchers at the U.S. National Institutes of Health (NIH) performed the first approved gene therapy procedure on a four-year-old girl named Ashanti DeSilva. Born with a rare genetic disease, severe combined immune deficiency (SCID), Ashanti lacked a healthy immune system and was extremely vulnerable to infection. Children with SCID usually develop overwhelming infections and rarely survive to (...) adulthood; even a common childhood illness like chicken pox is life-threatening. Ashanti led a cloistered existence, avoiding contact with people outside her family, remaining in the sterile environment of her home, and battling frequent illnesses with massive amounts of antibiotics.In Ashanti's gene therapy procedure, her own white blood cells were genetically modified and then infused back into her bloodstream. Laboratory tests show that the therapy has strengthened Ashanti's immune system. She no longer has recurrent colds, has been allowed to attend school, and has been immunized against whooping cough. This gene therapy procedure is not a cure, however. The genetically-treated white blood cells only survive for a few months and must then be replaced, but Ashanti's future is much brighter because of the new therapy (VI, Thompson [The First] 1993).Although this simplified description of Ashanti's gene therapy procedure sounds like a happy ending, it is little more than an optimistic chapter in a long story. The road to the first approved gene therapy procedure was rocky and fraught with controversy. The biology of human gene therapy is very complex, and there are still many techniques that need to be developed and diseases that need to be understood more fully before gene therapy is well established. The public policy debate surrounding the possible use of genetically engineered material in human subjects is equally complex. Major participants in the debate come from the fields of biology, government, law, medicine, philosophy, politics, and religion, each bringing different views to the discussion.In studying the ethics of gene therapy, one should draw a distinction between [End Page 63] therapy on somatic (non-reproductive) cells and germ (reproductive) cells. Only the germ cells carry the genes that will be passed on to the next generation. Reactions to gene therapy have varied widely. Some commentators on gene therapy object to any form of genetic manipulation, no matter how well-intentioned (VI, Rifkin 1983). Another reaction is to allow the use of somatic-cell therapy, but not to approve the use of germ-line therapy, which could have unforeseeable effects on future generations. A different stance is that, with proper regulation and safeguards, germ-line gene therapy is a logical extension of the progress made to date and that it is an ethically acceptable procedure.TechniquesTo date, 43 research protocols have been approved for somatic-cell gene therapy in the United States. The techniques employed in each protocol vary, but in general a virus is used as a "vector" to insert the desired gene into the DNA of the patient's cells, in order to compensate for a defective gene. For Ashanti's gene therapy, this technique involved obtaining white blood cells and introducing properly functioning genes into as many of the cells as possible. The normal genes were delivered through the use of a specially-engineered virus.Although similar techniques are used in germ-line gene therapy, the procedure is more difficult. There are two basic ways to perform germ-line gene therapy: (1) to treat a preimplantation embryo that carries a serious genetic defect before its implantation in the mother, which necessitates the use of in vitro fertilization techniques; or (2) to treat the germ cells (sperm or egg cells) of afflicted adults so that the genetic defects would not be passed on to their offspring, which requires the technical expertise to delete the defective gene and insert a properly functioning replacement. Because of the complexity of the procedures involved and the attendant ethical controversy, germ-line therapy is not currently performed.Candidate Diseases for Gene TherapyAt present, gene therapy is likely to be most successful in treating diseases that are caused by single-gene defects and has been approved for treating diseases such... (shrink)

Hereditary retinal degeneration due to mutations in visual genes may be amenable to therapeutic interventions that modulate, either positively or negatively, the amount of protein product. Some of the proteins involved in phototransduction are rapidly moved by a lightdependent mechanism between the inner segment and the outer segment in rod photoreceptor cells, and this phenomenon is important in phototransduction.

This chapter contains sections titled: Promise and Disappointment Ethical Issues Resource Allocation References.

It may be possible, one day, to use gene therapy to treat diseases whose genetic defects have been discerned. Because many genes responsible for inherited eye disorders within the retina have been identified, diseases of the eye are prime candidates for this form of therapy. The eye also has the advantage of being highly accessible with altered immunological properties, important considerations for easy delivery of virus and avoidance of systemic immune responses. Currently, adenovirus, adeno‐associated virus and lentivirus (...) have been used to successfully transfer genetic material to retinal pigment epithelium and photoreceptor cells. By harnessing therapeutic genes to these viruses, researchers have been able to demonstrate rescue in rodent models of retinitis pigmentosa, providing evidence that this form of therapy can be effective in delaying photoreceptor cell death. Future challenges include confirming therapeutic effects in animal models with eyes more anatomically similar to those of humans and demonstrating long‐term rescue with minimal toxicity. BioEssays 23:662–668, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

The prelims comprise: Introduction A (re)Defmition of what Human Gene Therapy is About Neurological Gene Therapy Ethics and Gene Therapy Acknowledgments Notes.

A major problem in developing an effective gene therapy for the nervous system lies in understanding the principles that maintain or turn off the expression of genes following their transfer into the CNS.

CRISPR is currently viewed as the central tool for future gene therapy. Yet, many prominent scientists and bioethicists have expressed ethical concerns around CRISPR gene therapy. This paper provides a critical review of concerns about CRISPR gene therapy as expressed in the mainstream academic literature, paired with replies also generally found in that literature. The expressed concerns can be categorised into three types depending on whether they stress risk/benefit ratio, autonomy and informed consent, or (...) concerns related to various aspects of justice. In the reviewed literature, we found no intrinsic objections to CRISPR gene therapy, even though many such objections were present in discussions of gene editing in the 1990s. The paper then proposes a brief outline for a practically applicable moral framework for public decision-making about CRISPR gene therapy and suggests how such a framework might be supported. We also suggest that this framework should govern public engagement about CRISPR gene therapy in order to reduce the risk that we make decisions about CRISPR gene therapy based on misperceptions, inflated views of risk, or unreasonable moral or religious views. (shrink)

The Japanese government took significant steps in making decisions about a newly developing clinical application of gene therapy when, on April 15, 1993, the Government officially accepted the Guidelines for Clinical Research on Gene Therapy submitted by the Health Science Council of the Ministry of Health and Welfare of Japan to the Minister.

In this paper, we apply the perspective of intra-organismal ecology by investigating a family of ecological models suitable to describe a gene therapy to a particular metabolic disorder, the adenosine deaminase deficiency (ADA-SCID). The gene therapy is modeled as the prospective ecological invasion of an organ (here, bone marrow) by genetically modified stem cells, which then operate niche construction in the cellular environment by releasing an enzyme they synthesize. We show that depending on the chosen order (...) (a choice that cannot be made on \textit{a priori} assumptions), different kinds of dynamics are expected, possibly leading to different therapeutic strategies. This drives us to discuss several features of the extension of ecology to intra-organismal ecology. (shrink)

Gene therapies to treat sickle cell disease are in development and are expected to have high costs. The large eligible population size — by far, the largest for a gene therapy — poses daunting budget challenges and threatens to exacerbate health disparities for Black patients, who make up the vast majority of American sickle cell patients.

Somatic cell gene therapy has yielded promising results. If germ cell gene therapy can be developed, the promise is even greater: hundreds of genetic diseases might be virtually eliminated. But some claim the procedure is morally unacceptable. We thoroughly and sympathetically examine several possible reasons for this claim but find them inadequate. There is no moral reason, then, not to develop and employ germ-line gene therapy. Taking the offensive, we argue next that medicine has (...) a prima facie moral obligation to do so. (shrink)

The prelims comprise: Germline Gene Therapy Genetic Enhancements The Genome and the Normative Status of Human Nature Conclusion Notes.

Aldehyde dehydrogenase 2 (ALDH2) deficiency constitutes one of the most common hereditary enzyme deficiencies, affecting 35% to 40% of East Asians and 8% of the world population. It causes the well-known Asian Alcohol Flush Syndrome, characterized by facial flushing, palpitation, tachycardia, nausea, and other unpleasant feelings when alcohol is consumed. It is also associated with a marked increase in the risk of a variety of serious disorders, including esophageal cancer and osteoporosis. Our recent studies with murine models have demonstrated that (...) a one-time administration of an adeno-associated virus (AAV) gene transfer vector expressing the human ALDH2 coding sequence (AAVrh.10hALDH2) will correct the deficiency state and prevent alcohol-induced abnormalities of the esophagus and bone. If successful in humans, such strategy would reduce the increased risk-associated disorders such as esophageal cancer and osteoporosis, but also prevent the Asian Alcohol Flush Syndrome. This treatment thus raises ethical concerns: although it would potentially prevent fatal disease, it could also allow affected individuals to drink alcohol without suffering the Asian Alcohol Flush Syndrome and, hence, potentially enable personal destructive behavior. Here we explore the ethical arguments against the development of a gene therapy for ALDH2 deficiency and we find them wanting. We contend that development of such treatments is ethically appropriate and should be part and parcel of the solutions offered against the condition. (shrink)

The article combines a criticism of public understanding of science with the sociology of expectations to examine how particular expectations toward scientific progress have performative effects for the construction of publics as citizens of science. By analyzing a particular controversy about gene therapy in Denmark, the article demonstrates how different sets of expectations can be used to discriminate among three different assemblages: the assemblage of consumption, the assemblage of comportment, and the assemblage of heroic action. Each of these (...) assemblages makes medical science, scientific citizenship, politics, patients, doctors, and expectations toward the future emerge in particular ways. By their radically different expectations toward science and their different constructions of what it means to be a scientific citizen, the assemblages construct the objectives of the governance of science in three very different ways. (shrink)

In this paper, we discuss the perspective of intra-organismal ecology by investigating a family of ecological models. We consider two types of models. First order models describe the population dynamics as being directly affected by ecological factors (here understood as nutrients, space, etc). They might be thought of as analogous to Aristotelian physics. Second order models describe the population dynamics as being indirectly affected, the ecological factors now affecting the derivative of the growth rate (that is, the population acceleration), possibly (...) through an impact on non-genetically inherited factors. Second order models might be thought of as analogous to Galilean physics. In the joint paper, we apply these ideas to a situation of gene therapy. (shrink)

Germ-line gene therapy, like many other medical technologies, raises questions of special concern to Christians. It not only raises questions about medical effects, actual or possible, of genetic interventions that would be inherited from one generation to another but also, more importantly, raises anthropological questions and so questions about parental attitudes. These are questions about the dignity and value of human life, about inter-human relations and about the God-human relationship.1 For this reason the paper starts with an exploration (...) of the implications of Christian anthropology, viewed from a Roman Catholic perspective. A set of conditions will be specified in the light of which germ-line gene therapy’s compatibility with Christian attitudes, a Christian understanding of the human being, and the meaning of human life can be assessed. (shrink)

Although the ability to perform gene therapy in human germ-line cells is still hypothetical, the rate of progress in molecular and cell biology suggests that it will only be a matter of time before reliable clinical techniques will be within reach. Three sets of arguments are commonly advanced against developing those techniques, respectively pointing to the clinical risks, social dangers and better alternatives. In this paper we analyze those arguments from the perspective of the client-centered ethos that traditionally (...) governs practice in medical genetics. This perspective clarifies the merits of these arguments for geneticists, and suggests useful new directions for the professional discussion of germ-line gene therapy. It suggests, for example, that the much discussed prospect of germ-line therapy in human pre-embryos may always be more problematic for medical genetics than adult germ-line interventions, even though the latter faces greater technical difficulties. (shrink)

Gene therapy is the modification of the human genetic code to prevent disease or cure illness. This technology is in its infancy and remains confined to experimental clinical trials. Once the present barriers are overcome, gene therapy will confront humanity with a host of ethical challenges. Therapies targeted to the genes of germ-line cells will introduce permanent changes to the human gene pool. Furthermore, nonmedical gene modifications have the potential to introduce a new form (...) of eugenics into our society by which some members attempt to become inherently superior to others and humanity is re-engineered to man-made specifications. National Catholic Bioethics Quarterly 10.1 (Spring 2010): 45–50. (shrink)

Neuwelt et al. have proposed gene-transfer experiments utilizing an animal model that offers many important advantages for investigating the feasibility of gene therapy in the human brain. A variety of tissues concerning the viral vector and mode of delivery of the corrective genes need to be resolved, however, before such therapy is scientifically supportable.

The prelude to successful human somatic gene therapy, i.e. the efficient transfer and expression of a variety of human genes into target cells, has already been accomplished in several systems. Safe methods have been devised to do this using non‐viral and viral vectors. Potentially therapeutic genes have been transferred into many accessible cell types, including hematopoietic cells, hepatocytes and cancer cells, in several different approaches to ex vivo gene therapy. Successful in vivo gene therapy (...) requires improvements in tissuetargeting and new vector design, which are already being sought. Gene‐transfer protocols have been approved for human use in inherited diseases, cancer and acquired disorders. Althouth the results of these trials to date have been somewhat disappointing, human somatic cell gene therapy promises to be an effective addition to the arsenal of approaches to the therapy of many human diseases in the 21st century if not sooner. (shrink)