Jewish Medical Ethics:
Genetic Screening & Genetic Therapy

by Fred Rosner, M.D.

Medical Ethics: Table of Contents | Organ Donation | Stem Cell Research

Introduction
Specific Examples

1. Huntington's Disease
2. Alzheimer's Disease
3. Breast Cancer
4. Tay Sachs Disease

Genetics and Eugenics in Classic Jewish Sources
The Genome Project and Judaism
Genetic Screening and Judaism
Gene Therapy and Genetic Engineering
Conclusion
References

Introduction

Genetic information about a person's health and health prospects can be inferred from the family history or by direct genetic testing. Such testing can involve sophisticated molecular analysis for the mutant gene (e.g., cystic fibrosis) or simple biochemical (e.g., hypercholesterolemia), enzymatic (e.g., Tay Sachs disease), hematological (e.g., Sickle cell diseases), or chromosomal (e.g., Down's syndrome) analysis of blood or body fluids or tissues.

The Human Genome Project, launched in 1988, is an international effort to map all human chromosomes and to sequence the three billion base pairs of nucleotides that make up the 100,000 genes on the unique chromosomes of every human being. The isolation and characterization of genes offers opportunities for disease and carrier state detection, diagnosis, screening, counseling, prevention, treatment and perhaps even cure by gene replacement or correction techniques yet to be developed. The ethical, legal, and social implications of the Human Genome Project are discussed at length in thousands of publication (1). The Project is under an international ethical microscope due to concerns about autonomy, privacy and confidentiality, justice, equity (2), uses and misuses of genetic information, commercialization (3), and conceptual and philosophical implications (4). The Project has been characterized as a Dr. Jekyll and Mr. Hyde monster because of the variety of legal and ethical issues concerning the individual, family and society (5).

Genetic testing and genetic screening can be performed at different stages of human development and life. Preimplantation diagnosis of a variety of genetic diseases is now possible whereby individual cells of a fertilized egg in vitro which has undergone several divisions (i.e., zygote) is tested for a mutant gene or gene product. Thus, two married carriers of the Tay Sachs gene can chose to discard an affected zygote and only implant an embryo free of the genetic disease into the mother's womb to assure the birth of an unaffected baby if the implantation and pregnancy are successful. Prenatal diagnosis by many techniques discerns whether a fetus is likely to have a serious defect (e.g., spine bifida) or a lethal disease (e.g., Tay Sachs disease). Many metabolic and genetic defects and disorders can be diagnosed prenatally. The consequence of detecting an affected fetus is to consider the possibility of terminating the pregnancy, an option that many people find objectionable for religious or other reasons.

Newborn screening of blood or tissue at or shortly after birth can detect genetic diseases such as phenylketonuria for which early intervention can prevent serious illness or death. Carrier screening identifies individuals who are clinically healthy but who have a gene or chromosomal abnormality which might result in an offspring with a serious or lethal disease (e.g., cystic fibrosis or Tay Sachs disease). Predictive testing of individuals for certain genes can be helpful in clarifying the risk for the development in later life of untreatable and incurable diseases (e.g., Huntington's disease) or conditions for which early intervention may prevent morbidity and even death (e.g., prophylactic hormone treatment or mastectomy for women at high risk for breast cancer -development). Susceptibility or workplace testing or screening is used to identify workers who may be susceptible to toxic substances in their workplace (e.g., glucose6-phosphate dehydrogenase deficient workers being exposed to oxidant drugs or chemicals). Finally, forensic genetic testing seeks to discover a genetic linkage between suspects and evidence found in criminal investigations (6).

The secular ethical issues raised by genetic testing and screening fall into three major categories: issues concerning education and counseling; problems involving confidentiality, and issues of justice (7). Some writers assert that genetic ethical issues are no different than those in other bioethical situations and that the new genetic technologies raise no new ethical questions for physicians or patients (8). Even if that is so, there are a number of factors, inherent in genetics which should heighten our sensitivity to the human values involved" (7). These factors include our ability to predict diseases which cannot be treated or cured (e.g., Huntington's disease); ambiguities in the concept of genetic disease (Does a gene carrier for a recessive disease have a genetic disorder? Is a person who will later develop Huntington's disease ill?); poorly understood concepts of genetics and risk by the public; the potential for injustice because of racial and ethnic differences in genetic diseases; the intimate relationship between genetic inheritance and personal identity (genetics ties us to our ancestors and our descendants); the fact that genetic information also affects others, especially family members; and the disproportionate burden on women in screening, choice to abort or not abort, and the consequences of that choice (7).

Points to consider before embarking on carrier screening programs include the nature and frequency of the disorder and availability and effectiveness of treatment, community perception of the disorder and attitudes to screening, motivation for screening, how the test is done and what the results mean, obtaining informed consent and confidentiality of results, when to screen, education before screening, possible stigmatization and discrimination, and the organization of the screening program (9). The Council on Ethical and Judicial Affairs of the American Medical Association has addressed ethical issues related to prenatal genetic testing (10), genetic testing by employers (11), and insurers (12) and carrier screening for cystic fibrosis and other disorders (13).

In screening for genetic diseases, society has not yet adequately addressed the important issues of the clinical limitations of DNA-based screening tests (inconclusive linkage studies, insensitivity of the test, variable expressivity of the gene, laboratory quality control, misinterpretation of test results); the pressures for genetic testing from individual patients, insurers, employers, biotechnology companies); the threat of genetic discrimination; informed consent for genetic screening, and confidentiality of test results (including disclosure or non-disclosure of incidental findings such as nonpaternity and data banks) (14).

How does society control the obtaining and use of genetic information? How does society monitor and review genetic screening programs? What criteria should be set to make maximum use of the potential good that the Human Genome Project offers without infringing on the ethical and legal principles of privacy, autonomy, beneficence, confidentiality and non-discrimination? Who owns genetic information? How should genetic information be used? Who decides who should be screened? Are there or should there be limits to preimplantation, prenatal and neonatal screening? How should employers and insurers receive and use (and not abuse) genetic information? Do we have sufficient data to judge the pros and cons of genetic testing and screening? Can or should genetic abortion be divorced from the national debate on abortion? How can access to testing be provided for all who seek it?

As the range of conditions for which pre- and postnatal testing expands, society and the medical profession need to develop guidelines about which tests ought to be offered. Notions of fetal privacy and confidentiality may help to define limits to the application of screening and testing technology (15). The psychosocial effects of screening for disease prevention and detection need to be seriously considered.

Information about disease susceptibility may lead to anxiety and strain family relations. Individual physicians and society as a whole should take steps to maximize the benefits of genetic testing and minimize the harms. Such steps include pretesting education and counseling; the urging of disclosure of positive results to spouses, partners and relatives; the protection of confidentiality; and the forbidding of unwarranted disclosure of test results, discrimination in employment, housing or insurance, and denial of access to medical care and health insurance (14).

The genetic testing and counseling of children and adolescents is associated with special ethical, legal and psychological implications (17). Risks and benefits of testing have to be assessed to determine whether it is in the child's best interests to be tested (18).

Specific Examples

Huntington's disease

Presymptomatic genetic testing for Huntington's disease is now available in a number of centers throughout the United States and elsewhere. The number of individuals tested, however, is relatively small, perhaps due to limited accessibility of test centers as well as fear of a positive or high risk result, the lack of a cure, and the threat of losing one's health insurance (19). Should a person with a family history of Huntington's disease be tested? When should such presymptomatic testing be done? The psychological relief of those whose test is negative is obvious. But what do people with a positive test do with that information? Planning for one's future life may be difficult because of the psychological trauma that such people may suffer following testing (20). Prenatal screening for late onset Huntington's disease involves numerous ethical issues including the selective abortion of affected fetuses to avoid the birth of a "healthy" person who will eventually die from this debilitating disease (21).

Alzheimer Disease

There is general consensus that apolipoprotein E genotype is strongly associated with Alzheimer disease. However, the test does not provide sufficient sensitivity or specificity. Therefore, at the present time, it is not recommended for use in routine clinical diagnosis nor for predictive testing (22-23). However, genetic screening for Alzheimer disease will become more common in the future. Hence, ethical concerns of presymptomatic screening and disclosure; prenatal screening and selective abortion; justice, access and allocation of resources for testing, counseling and treatment (if and when they become available) need to be considered (24).

Breast cancer

About five or ten percent of all breast cancer is hereditary. The breast cancer genes known as BRCA 1 and BRCA 2 are responsible for most inherited breast cancer, especially in women who develop the disease before the age of 40 years. The BRCA 1 mutation known as 185delAG is found in approximately 1% of the Ashkenazi Jewish population (25) and in 20% of Ashkenazi Jewish women who have breast cancer before 40 (26) or 42 (27) years of age. This gene is also associated with an increased risk of ovarian cancer. These findings and observations are cause for both gladness and serious worry and concern (28). On the one hand, early interventions may be possible in high risk women who test positive (e.g., surveillance, prophylactic mastectomy, hormone prophylaxis) and anxiety reduction may occur in those who test negative. On the other hand, confidentiality, access, autonomy, informed consent including the implications of a positive or negative test, technical accuracy of the test, costs involved in testing, possible job, insurance and housing discrimination, options for risk estimation without testing, risk for psychological harm to both carrier and relatives, education and counseling, are all serious issues of concern.

The availability of a test does not require that it be universally offered. The American Society of Clinical Oncology recommends that cancer predisposition testing be offered only when the person has a strong family history of cancer or very early age of onset of disease; when the test can be adequately interpreted; and when the results will influence the medical management of the patient or family member (29). Many other prestigious organizations emphasize the need for BRCA 1 testing to remain a research activity for the time being (30). The pitfalls of genetic testing (31) and the psychological issues in testing for breast cancer susceptibility (32) should not be mimicked. People at risk must fully understand the risks, benefits, and limitations of genetic testing, the risk of psychological harm, and the possibility of insurance discrimination and subsequent loss of health care coverage, before they undergo testing (33).

Tay Sachs Disease

Debates continue about the screening of large populations of Jewish people for the carrier state of Tay Sachs disease to prevent "inappropriate" marriage of two carriers. Also controversial is the performance of amniocentesis for the prenatal detection of the fatal disease with possible abortion of an affected fetus. Selected termination of affected fetuses may not be, acceptable in Judaism although some Rabbis might sanction such a procedure. Mass screening programs may produce a psychological burden on those young people who screen positive. Should a carrier of the Tay Sachs gene refuse to marry a mate who has not been tested? Should two carriers break up an engagement if they learn that both are carriers as a result of a screening program? Should a young person inquire about the Tay Sachs status of a member of the opposite sex prior to meeting that individual on a social level? Must a person who knows he or she is a carrier divulge this fact to an intended spouse? Is primary prevention of Tay Sachs disease by mate selection the proper Jewish approach?

The stigma of being a carrier of the Tay Sachs gene may not be fully appreciated. Misinformed or uninformed people may shun and ostracize such carriers. Job and insurance discrimination is also possible if confidentiality of testing results is not assured. If the purpose of Tay Sachs screening is to provide eligible clients with information and genetic counseling about mating and reproductive options, few will oppose screening. If the purpose, however, is to suggest prenatal diagnosis with the specific intent of recommending abortion of affected fetuses, religious and moral objections might be raised. Preimplantation diagnosis of in vitro fertilized eggs with the discarding of affected zygotes, if any, avoids the issue of pregnancy termination since pregnancy in Judaism does not begin until zygote implantation into the wall of the uterus.

Genetics and Eugenics in Classic Jewish Sources

Ancient Jewish writings, including the Bible and Talmud, are not devoid of material relating to genetics. One writer describes in some detail how the laws of Mendelian genetics were applied by Jacob in the biblical narrative (Genesis 30:32 ff) of the speckled and spotted sheep (34). Hemophilia and its precise genetic transmission is described in the Talmud (Yebamot 64b). The Sages in the Talmud and subsequent rabbinic authorities had a remarkable knowledge of the genetics of this sex-linked disorder (38). All Rabbis recognized that females transmit the disease but do not suffer from it. A few Rabbis also considered the possibility of its transmission through males.

Elsewhere (Ketubot 10b), the Talmud portrays a family whose women had hereditary absence of menstruation and no blood of virginity and were obviously childless. The exact nature of the anatomical or physiological abnormality is not described.

It is prohibited in Jewish law to marry a woman from a family of epileptics or lepers (Yebamot 64b; Maimonides' Mishneh Torah, Issurei Biyah 21:30; Karo's Shulchan Aruch, Even Haezer 2:7) lest the illness be genetically transmitted to future generations. According to Rashi (Yebamot 64b), any hereditary disease is included in this category. This talmudic ruling may well represent the first eugenic enactment, and the only legislative bar to the procreation of a diseased progeny, in ancient and even medieval times" (36). On the basis of the higher frequency of defective births resulting from unions among blood relatives, Rabbi Judah the Pious, in his Ethical will, prohibited marriages between first cousins and between uncles and nieces. Yet such marriages are sanctioned in the Bible and expressly encouraged in the Talmud (Yebamot 62b and Sanhedrin 76b), perhaps to propagate good genes. Since consanguineous marriages do not cause birth defects but merely increase their risk, most Rabbis do not ban such marriages (37-38). Some Rabbis, however, strongly caution against it (39-41).

Genetic disease was recognized by Maimonides who prescribes a regimen of health for all Jews to remain healthy, since one cannot serve the Lord when one is ill (Mishneh Torah, Deot 4:1). He guarantees anyone who follows his regimen that he will be healthy all his life unless he was born with a hereditary or genetic defect (Ibid. 4:20).

In a moral teaching of the Talmud, (Niddah 31a), it is stated that there are three partners in the creation of a human being: God, the father and the mother. The father provides the white (sperm) from which are derived the child's bones and sinews, his nails, the marrow in the head (brain) and the white of the eye. The mother provides the red (menstrual blood) from which are derived skin and flesh and blood and hair and the black of the eye. God gives the spirit and the soul, beauty of features, sight of the eyes, hearing of the ears, speech of the mouth, the ability to move the hands and walk with the feet, understanding and discernment.

The definition and importance of the precise determination of paternity in relation to numerous Judaic laws is exhaustively discussed in a recent article (42) and includes genetic testing for blood groups, tissue typing, blood enzyme testing, anthropological examinations and molecular genetics.

The Genome Project and Judaism

Is the genome project an encroachment on the Divine plan for this world by interfering with nature as God created it? Is genetic engineering changing the Divine arrangement of Creation? Although one Rabbi answers in the affirmative (43), most Rabbis consider the acquisition of knowledge for the sake of finding cures for human illnesses to be divinely sanctioned, if not in fact mandated. God blessed mankind with the phrase: replenish the earth and subdue it (Genesis 1:28). This phrase is interpreted by Nachmanides (Ramban) to mean that God gave man dominion over the world to use animals and insects and all creeping things for the benefit of mankind. To subdue the earth, according to Samson Raphael Hirsch, is to master, appropriate, and transform the earth and its products for human purposes. To have dominion over the fish and over the birds and over every living thing on earth (Genesis 1:28) means to use them for the benefit of mankind. The pursuit of scientific knowledge is not considered to constitute prohibited eating from the tree of knowledge (Genesis 2:17). Whatever is good for mankind must be permissible and praiseworthy. However, good is often not pure good but mixed with some potential danger. The genome project is certainly good in terms of its potential to lead to cure of diseases but the project also raises many concerns.

In the general introduction to his Commentary on the Mishnah (44), Moses Maimonides writes a protracted dissertation on knowledge and wisdom and the existence and purpose of all living and inanimate things in the world. He clearly enunciates the thesis that everything that, God put on this earth is to serve mankind. Thus, scientific experiments on laboratory animals during the course of medical research that might find cures for human illnesses are sanctioned in Jewish law as legitimate utilization of animals for the benefit of mankind (45). However, whenever possible, pain or discomfort should be avoided or minimized in order not to transgress the prohibition in Jewish law against cruelty to animals.

King David said that, The heavens are the Lord's heavens but the earth He has given to mankind (Psalms 115:16) further supporting the concept that knowledge and its pursuit are legitimate activities for human beings and not considered an encroachment upon Divine prerogatives. Thus, therapeutic genetic engineering and gene therapy that may result from the knowledge derived from the genome project is not a Torah violation of undermining God's creation of the world by manipulating nature (Ramban, Leviticus 19:19). On the contrary, it is a confirmation of the creation of the world. The use of scientific knowledge to benefit mankind is biblically mandated (Ramban, Genesis 1:28). The use of such knowledge to heal illness and cure disease is also biblically allowed based on the talmudic interpretation (Babe Kamma 85a) of the phrase and heal he shall heal (Exodus 21: 19), or even biblically mandated based on Maimonides' interpretation (Mishnah Commentary, Nedarim 4:4) of the biblical obligation to restore a lost object (Deuteronomy 22:2) to include the restoration of one's lost health. The healing of illness includes the use of genetically engineered medications such as insulin and various antibiotics. The cure of disease by gene therapy, if possible, is also sanctioned in Jewish law.

Genetic Screening and Judaism

Many years ago, Rabbi Moshe Feinstein was asked whether or not it is advisable for a boy or girl to be screened for Tay Sachs disease, and if it is proper, at what age the test should be performed. His answer was:

... it is advisable for one preparing to be married, to have himself tested. It is also proper to publicize the fact, via newspapers and other media, that such a test is available. It is clear and certain that absolute secrecy must be maintained to prevent anyone from learning the result of such a test performed on another. The physician must not reveal these to anyone... these tests must be performed in private, and, consequently, it is not proper to schedule these test in large groups as, for example, in Yeshivas, schools, or other similar situations (46).

Rabbi Feinstein also points out that most young people are quite sensitive to nervous tension or psychological stress and, therefore, young men (below age twenty) or women (below age eighteen) not yet contemplating marriage should not be screened for Tay Sachs disease. Finally, Rabbi Feinstein strongly condemns abortion for Tay Sachs disease and even questions the permissibility of the amniocentesis which proves the presence of a Tay Sachs fetus, since amniocentesis is not without risk, albeit small (47).

Rabbi Eliezer Yehudah Waldenberg allows abortion following amniocentesis during the first trimester if the fetus is determined to have Tay Sachs disease. "If there is a strong suspicion that the fetus will be born physically deformed and suffer greatly, one can allow abortion prior to forty days of conception and perhaps even up to three months of the pregnancy before the fetus, begins to move" (48). Waldenberg also allows termination of pregnancy far Tay Sachs disease up to the seventh month of pregnancy because the defect, the anguish, the shame, the physical and mental pain and suffering of the parents are inestimable. (49).

Rabbi J. David Bleich indicates that the elimination of Tay Sachs disease is, of course, a goal to which all concerned individuals subscribe. He points out, however, that the obligation with regard to procreation is not suspended simply because of the statistical probability that some children of the union may be deformed or abnormal. While the couple may quite properly be counseled with regard to the risks of having a Tay Sachs child, failure to bear natural children is not a halachically [Jewish legal] viable alternative. He further voices concern that if the fetus is found to have Tay Sachs disease by prenatal testing, abortion may not be sanctioned in Jewish law (50). Rabbi Bleich concludes that screening programs for the detection of carriers of Tay Sachs disease are certainly to be encouraged." He suggests that the most propitious time for such screening is childhood or early adolescence, since early awareness of a carrier state, particularly as part of a mass screening program, is advantageous. He is critical of Rabbi Waldenberg and points out that the latter's permissive ruling on abortion for Tay Sachs disease is contrary to the decisions of other contemporary rabbinic scholars including Rabbi Feinstein.

Two methods now exist for totally eliminating the need for prenatal screening for Tay Sachs disease and the serious halachic objections to abortion if the fetus is found to be affected. The first method is to perform confidential premarital screening and to strongly discourage the marriage of two carriers. This approach is widely utilized in many orthodox Jewish communities and is under the sponsorship of the Dor Yeshorim organization [160 Wilson Street, Brooklyn, NY 11211, (718) 384-6060] which claims to have tested over 70,000 people and identified over 100 at risk couples who were advised to avoid such at risk marriages. In Israel, such a program to screen for carriers of Tay Sachs disease since 1986 has resulted in no Tay Sachs children being born to newlywed couples in the ultra orthodox Ashkenazi Jewish community (51).

The second method to prevent the birth of a Tay Sachs baby is to perform preimplantation screening of the in vitro fertilized zygotes if both husband and wife are known carriers and to only use the healthy ones for implantation. The discarding of the affected zygotes is not considered as abortion since the status of a fetus or a potential life in Judaism applies only to a fetus implanted and growing in the mother's womb. This artificial method of conception is sanctioned by many Rabbis for couples who cannot have a child in the normal way in order to enable them to have a child, albeit by assisted reproduction (52). The Jewish legal question of using artificial means of conception to screen potential fetuses for genetic diseases has yet to be ruled on decisively by modern rabbinic authorities. This seems to be an ethically acceptable option for couples where both husband and wife are carriers of a recessive genetic disease such as Tay Sachs or if one partner is a carrier of a dominant gene such as Huntington's disease or of a sex-linked genetic disease such as hemophilia.

It is not clear whether Judaism sanctions genetic screening for diseases for which no effective treatment yet exists. Judaism is greatly concerned about the emotional burden (tiruf hadeaf) that such knowledge may place upon a person found to have the gene for Huntington's disease in the presymptomatic stage. Judaism would also not sanction the prenatal testing for Huntington's disease if the only purpose is to abort the fetus if it is found to be affected. Preimplantation screening of Huntington's disease and the choosing of only unaffected zygotes for implantation may be permissible to prevent the birth of an affected child as described above for the prevention of Tay Sachs disease. The same permissive view might apply to the prevention of hemophilia births by preimplantation screening.

Newborn screening for treatable diseases such as phenylketonuria and congenital hypothyroidism should certainly be done. Judaism subsumes such testing under the biblical and rabbinic mandates to patients to seek healing from the medical profession.

Judaism requires that confidentiality of test results for all types of genetic screening be maintained. The prohibitions in Judaism against talebearing (Leviticus 19:16) and evil gossip (Psalms 34:14) are discussed at length in the Talmud (Yoma 4b, Sanhedrin 31 a) and in the Codes of Jewish law such as Maimonides' Mishneh Torah (Deot 7:2). An entire book was written on this subject by Rabbi Israel Meir Hakohen of Radin, popularly known as Chafetz Chayim (53). These prohibitions require that professional confidences between patient and physician be maintained. Whether the physician obtains such confidential information, genetic or otherwise, from the patient or from others, he is forbidden to disclose that information or share it with anyone including the patient's family and even professional colleagues, if no benefit to the patient would result therefrom. However, K the maintenance of confidence might cause serious physical, financial, or emotional harm to another person, the latter may be informed. Thus, a person who is the carrier of a serious and potentially lethal genetic disorder is obligated to divulge that information to a prospective spouse.

More difficult to resolve is the question as to whether or not an Ashkenazi Jewish woman with the gene for breast cancer BRCA 1 or BRCA 2 is obligated to tell that to a prospective spouse or to her husband K she is already married. Modern rabbinic authorities have not yet ruled on whether it is even appropriate to test for that gene in all Jewish women. It may be reasonable to do so in women with very strong family histories of breast cancer. But to what end? If they are found not to have the gene, then risk of developing breast cancer is still high. But women found to be positive for the gene may wish to take action such as more frequent mammography, prophylactic hormonal treatment, or even prophylactic mastectomies. Current rabbinic authorities need to address these urgent questions to provide guidance on the Jewish religious views on these genetic issues. Should genetic screening include diseases where the clinical outcome is uncertain. For example, in cystic fibrosis, Gaucher's disease, hemophilia and other diseases, early death is rare and the disease expression may be mild, moderate, severe, or life threatening even through adolescence and early adulthood.

Gene Therapy and Genetic Engineering

The literature on gene therapy and genetic engineering in Jewish law is very sparse indeed. Two rabbinic articles with genetic engineering in their titles deal primarily with artificial insemination, in vitro fertilization and surrogate motherhood, and only briefly mention cloning (54-55). The production of hormones such as insulin and erythropoietin, and antibiotics and other therapeutic substances, by genetic - engineering through recombinant DNA technology is certainly permissible in Jewish law because nature is being properly used by man for his benefit for the treatment and cure of illnesses. Gene therapy, such as the replacement of the missing enzyme in Tay Sachs disease or the missing hormone in diabetes, or the repair of the defective gene in hemophilia or Huntington's disease, if and when these become scientifically feasible, is also probably sanctioned in Jewish law because it is meant to restore health and preserve and prolong life.

The technical medical problems of modifying the defective gene or genes in an individual sperm or ovum or zygote by gene surgery and implanting the replaced or repaired genes into the mother thereby producing a healthy child have not yet been surmounted. However, assuming such surgery can be successfully performed, gene surgery will probably be sanctioned by rabbinic authorities as a legitimate implementation of the mandate on physicians to heal the sick. Further, argues Rabbi Azriel Rosenfeld (56), genes are submicroscopic particles and no process invisible to the naked eye is forbidden in Jewish law. For example, laws of forbidden foods do not apply to microorganisms. In addition, a priest only declares ritually unclean that which his eyes can see.

Another argument favoring the permissibility of gene surgery or genetic manipulation is the fact that the sperm or ovum or even the fertilized zygote is not a person. Thus, gene manipulation is not considered as tampering with an existing or even potential human being since that status in Jewish law is only bestowed upon a fetus implanted in the mother's womb. One can also argue that any surgery performed on a live human being must certainly be permitted on a sperm or ovum or fertilized zygote. For example, if a surgical cure for hemophilia, Tay Sachs disease or Huntington's disease were possible, it would surely be permissible. Hence, it should certainly be permissible to cure or prevent these diseases by gene surgery.

If it were possible to perform gene transplants by transplantation of genes from one person into the ovum or sperm of another, the following Jewish legal questions would arise: Are gene transplants considered to be a type of perverted sex act between the gene donor and the recipient? Would such transplants be forbidden, in particular, if donor and recipient are close relatives? Would a child conceived from such a manipulated ovum or sperm be regarded as related to the gene donor? Can one draw parallels from rabbinic response dealing with ovarian transplants and conclude that since no sex act is involved in a gene transplant, the recipient is not forbidden to marry the donor's relative, and the child conceived and born following a gene transplant is not related to the gene donor? In most organ transplants (kidney, cornea, heart, ovary, genes) the organ becomes an integral part of the recipient.

Rabbi Moshe Hershler warns against blinding ourselves to the potential of genetic engineering and gene therapy, which is no longer a dream or a fantasy but becoming a medical and scientific reality (43). Hershler raises the question of the permissibility (or lack thereof) of experimenting with gene therapy to try to save the life of a child with thalassemia or Tay Sachs disease if the unsuccessful outcome of the experimentation would be a shortening of the child's life. Hershler is of the opinion that gene therapy and genetic engineering may be prohibited because he who changes the [Divine] arrangement of creation is lacking faith [in the Creator], and he cites as support for his view the prohibition against mating diverse kinds of animals, sowing together diverse kinds of seeds, and wearing garments made of wool and linen (Leviticus 19:19). This line of reasoning is rejected by Rabbis Shlomo Zalman Auerbach and Yehoshua J. Neuwirth (57) since genetic engineering does not seem to be comparable to the grafting of diverse types of animals or seed. The main purposes of gene therapy are to cure disease, restore health, and prolong life, all goals within the physician's Divine license to heal. Gene grafting is no different than an "organ graft," such as a kidney or corneal transplant, which nearly all rabbis consider permissible.

Ethical and halachic problems associated with genetic engineering include speciation. Does a certain species lose its identity if other genes are introduced into it? Would the citron or ethrog (Citrus medica Linn) used on the Tabernacles holiday for religious purposes lose its identity if lemon genes were introduced into it? How many transplanted lemon genes are needed to consider the ethrog to be a lemon? Can the rabbinic concept of nullification (bitul) be applied to this situation? Another example is the need for fins and scales for fish to be kosher for consumption. If genes introduced in a scaleless caffish induce scalation, does the catfish then become a kosher fish? Yet another example is the conversion by genetic engineering of annual plants into perennials. The latter are not subject to some of the laws of the Sabbatical year. Thus perennial wheat, corn or tomatoes would be permitted in Jewish law even if grown during the Sabbatical year. These problems and issues have not yet been decisively discussed and resolved by current halachic authorities.

It seems clear that genetic engineering and gene therapy can and should be used to treat, cure or prevent disease. But should these techniques be allowed to alter human traits such as eye color, height, personality, intelligence and facial features? Probably not, although some Rabbis including Rabbi Moshe Feinstein allow elective surgery to improve one's beauty or physical features to help in spouse selection (58). If tall basketball players are more successful than short ones, should we only produce tall basketball players? Obviously not? Should we create piano players with three hands? Obviously not? Should we create super microorganisms for agricultural purposes? Perhaps, but they may also be used for germ warfare and should, therefore, be disallowed. The Talmud relates (Pesachim 54a) that God inspired Adam with a type of Divine knowledge, and he took two heterogeneous animals and crossed them and created a mule. Elsewhere, the Talmud asks (Chullin 7b) why they are called mules (Hebrew yemim) and answers "because they cast fear [Hebrew emah] upon men." This inappropriate use of nature by Adam is what Ramban condemns in his biblical commentary (Leviticus 19:19) as changing and denying the Divine creation of the world."

To attempt to clone a human being is certainly prohibited in Judaism although an example of the creation of an artificial human being or golem is cited in the Talmud (Sanhedrin 65b). The possible deleterious effects of genetic engineering and gene therapy are not yet fully know. Can such genetic manipulation unmask inactive cancer genes? Thus, in addition to the medical and scientific aspects of genetic engineering and DNA recombinant research, the spiritual and theological aspects also require exploration. Rabbis must examine these issues from the Jewish viewpoint and offer halachic guidance to the medical and lay communities.

Conclusion

Genetic screening, gene therapy and other applications of genetic engineering are permissible in Judaism when used for the treatment, cure, or prevention of disease. Such genetic manipulation is not considered to be a violation of God's natural law but a legitimate implementation of the biblical mandate to heal. If Tay Sachs disease, diabetes, hemophilia, cystic fibrosis, Huntington's disease or other genetic diseases can be cured or prevented by gene surgery, it is certainly halachically permitted.

Genetic premarital screening is encouraged in Judaism for the purpose of discouraging at risk marriages for a fatal illness such as Tay Sachs disease. Neonatal screening for treatable conditions such as phenylketonuria is certainly desirable and perhaps required in Jewish law. Preimplantation screening and the use of only healthy zygotes for implantation into the mother's womb to prevent the birth of an affected child is also probably sanctioned in Jewish law. Whether or not these assisted reproduction techniques can be used to choose the sex of one's offspring to prevent the birth of a child with a sex-linked disease such as hemophilia has not yet been ruled on by modern rabbinic decisors (59). Prenatal screening with the specific intent of aborting an affected fetus is not allowed according to most rabbinic authorities although a minority view permits it "for great need." Not to have children if both parents are carriers of genetic diseases such as Tay Sachs is not a Jewish option. Preimplantation screening is preferable. All screening test results must remain confidential. To improve physical traits and characteristics such as height, eye and hair color, facial features and the like, is frowned about in Judaism if it serves no useful medical or psychological purpose. The cloning of microorganisms such as bacteria and viruses for the benefit of mankind such as the synthesis of insulin, growth hormone and a wide variety of therapeutic substances to treat and cure illnesses is certainly permissible. But to unleash superbacteria into the world for non-therapeutic and perhaps even evil purposes is totally contrary to Jewish ethics. The cloning of man is prohibited as a violation of the Divine arrangement of the world and the creation of man in the image of God. Rabbi Immanuel Jakobovits expresses sentiments which we should all take to heart:

It is indefensible to initiate uncontrolled experiments with incalculable effects on the balance of nature and the preservation of man's incomparable spirituality without the most careful evaluation of the likely consequences beforehand ... Spare part" surgery and genetic engineering may open a wonderful chapter in the history of healing. But without prior agreement on restraints and the strictest limitations, such mechanization of human life may also herald irretrievable disaster resulting from man's encroachment upon nature's preserves, from assessing human beings by their potential value as tool-parts, sperm donors or living incubators, and from replacing the matchless destiny of the human personality by test-tubes, syringes and the soulless artificiality of computerized numbers. Man, as the delicately balanced fusion of body, mind and soul, can never be the mere product of laboratory conditions and scientific ingenuity. To fulfill his destiny as a creative creature in the image of his Creator, he must be generated and reared out of the intimate love joining husband and wife together, out of identifiable parents who care for the development of their offspring, and out of a home which provides affectionate warmth and compassion (36).

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Sources: The Institute for Jewish Medical Ethics

Fred Rosner is Director, Department of Medicine, Mount Sinai Services at Queens Hospital Center, Jamaica; Professor of Medicine, Mount Sinai School of Medicine, New York City