There is no perfect human genome. Mutations (which are analogous to “spelling mistakes” in the DNA) are an essential property of everyone’s genome. If our DNA did not have the capacity to mutate, we would all be dead. When an organism gets a bacterial infection, it engages specific immune cells to start mutating their own DNA. Each of these cells tries to randomly generate an antibody that would have the capacity to stimulate the immune system and eradicate the bacteria. The immune cell that actually generates “therapeutic antibodies” for that specific bacterium is then preserved. It divides to create millions of cells to make the right amounts of antibody to cure the individual. Every individual has many genetic mutations. We are all defective, and we should be humbled by that knowledge.
Applications of DNA Technology
There are many implications in the application of DNA technology. For instance, what are the halakhic implications of DNA technologies in forensic medicine? Are Jews allowed to use genetic or DNA technology to identify a dead body? Since each person has a unique DNA alphabet or pattern, this information can be used to identify parenthood. Are we allowed to use this technology to identify the biological father or mother of a child?
Studies have shown that in a significant percent of cases of couples who underwent genetic analysis to find out if a child will be affected by a disease, the husband was not the biological father. (Mahowald 1998) From the halakhic point of view, what should be done with such information? Can a husband tell his wife that he wants to take a DNA test to prove whether their child is his son or daughter? What are the halakhic implications if the test shows that the husband is not the father? Would this information be halakhic grounds for a divorce?
DNA testing is used in criminal investigations. We do not yet know how to apply genetic analysis to identify ethnicity and race, but it is likely that the technology will be developed to do this in the near future.
Scientists have discovered common genetic markers (DNA sequences) in all Kohanim. What would be the halakhic implications of testing someone who thinks he is a Kohen and finds out that his genetic profile is not that of a Kohen? Do we rely on the tradition of his father and forefathers or on genetics?
Genetic analysis has a highly accurate prediction outcome for most Mendelian-based diseases, but it is not 100 percent accurate. There are rare cases of babies who have both gene mutations for Tay-Sachs but are perfectly healthy. There are many other diseases in which genetic profiling is associated with an increased risk of getting certain diseases, such as cancer, Parkinson’s, Alzheimer’s, obesity, heart disease, or behavioral problems. What are the halakhic consequences in testing for these diseases or behavior characteristics? Does such testing violate genetic privacy?
We know that halakhah recognizes the importance of enhancing fertility and producing healthy children. Pre-implantation genetic diagnosis (PGD), amniocentesis, and chorionic villus sampling (CVS) are all methods for assessing the genetic status of a fetus. Currently most of these procedures, except for amniocentesis, are performed after ten to fourteen weeks of gestation. At that point is it halakhically permissible to terminate the pregnancy? Rabbi Eliezer Waldenberg ruled in his responsa Tseits Eliezer under what circumstance this may be permissible, but other authorities say that this is not allowed after forty days of gestation.
What about future technologies? We may one day be able to implant a nano-chip in a newly pregnant woman to capture fetal cells that escape from the fetus and circulate in the mother’s blood. The chip could be removed before the fortieth day of gestation. The fetal cells that are collected in this nano-chip could then be analyzed to determine if the fetus is carrying a genetic defect that causes Tay-Sachs or cystic fibrosis. Since this would be done before the fortieth day of gestation, rabbinical authorities might then allow the pregnancy to be terminated when a fetus carries such severe genetic defects.
There are already a few physicians in the United States conducting chorionic villus sampling (CVS) early in the pregnancy. New technologies allow the removal of a small sample of tissue from the chorion (the outermost membrane of the placenta) with a needle without harming the fetus. Because one or two fetal cells are enough for the genetic analysis of potential genetic defects, this can be done before the thirtieth day of pregnancy.
There also is a new technology being developed at Columbia University and other places for collecting the vaginal fluid of a newly pregnant woman during the first two weeks. Fetal cells contained in this fluid can be isolated and tested for genetic traits.
From the halakhic point of view, the advantage of these new technologies is that they can be performed before the fortieth day of gestation, when it may be permissible to terminate the pregnancy. This would enable couples who are carriers of genetic diseases to marry and have healthy children. This is psychologically easier than the Dor Yeshorim method of premarital screening, which is not conducted until the couple has been going out for several months. If both partners are carriers of a genetic disease but want to marry, these new technologies would enable them to marry and have healthy children. If they accept the possibility of terminating pregnancy before forty days, they have the options of early diagnosis, PGD, or early testing of the fetus.
There are complicated halakhic issues involved in these options, though. If a couple wants to use PGD, they have to use contraception during all their fertile years. This is not a trivial situation, and it requires a lot of education. Moreover, not all rabbinic authorities agree that pregnancy can be terminated during the first forty days. Every couple has to consult an appropriate rabbi before making such a crucial decision.
Can the new DNA technologies be used to predict cancer? This is a multifactorial disease involving many genes. Until we know the entire human genome, we cannot make accurate predictions. Moreover, the majority of cancers do not have genetic family history. Environment plays an important role here. In January 2009 in London a woman underwent PGD in order to select a child free of the BRCA1 cancer-causing mutation. The halakhic position on this has yet to be clarified.
Preventing Disease by Proper Habits and Diet
There are many less technological ways to help prevent diseases. For instance, restricting sugar in the diet enhances the health of lung cells and reduces the chances of the development of lung cancer. We all know that smoking causes cancer, but we are just beginning to understand that smoking cigarettes can cause mutations. The more mutations a person has, the greater the probability of contracting lung cancer. The Internet site HealthMad http://healthmad.com/health/smoking-change-the-entire-dna claims that on the average, one genetic mutation occurs for every fifteen cigarettes smoked. Finally, tumors hate company. Research shows that people who communicate well socially, especially women, have a lower incidence of cancer than those who live in isolation. (Fox 1995) This data supports the mitsvah of bikur holim, visiting the sick. Social interaction is a powerful protection against various diseases.
Good nutrition is also helpful in preventing disease. For instance, the seven species of the Land of Israel listed in Deuteronomy 8:8 all have evidence-based health benefits. Wheat contains vitamin B and helps prevent sterility and balances body weight. Barley has cholesterol-lowering properties. Red grapes lower cholesterol and contain resveratrol, an effective agent for cancer chemoprevention and an anti-aging compound. Figs lower cholesterol, control the onset of diabetes, and lower blood pressure. Pomegranates help control osteoarthritis, blood pressure, and lower the risk of Alzheimer’s disease. Olive oil has anti-aging properties, protects the heart, and fights cancer. Dates help develop muscles, prevent abdominal cancers, and control weight. (See also Maimonides on Exodus 15:26.)
Genetic Prediction of Behavior
Can genetic analysis predict behavior? Should a fetus be tested for aggression, sexual preference, and other traits? Although not all genetic predispositions lead to a certain behavior if a person makes the effort to overcome them, it is argued that some predispositions are so powerful that the majority of people carrying them cannot control them.
Can athletic skills be genetically determined? For a fee of ninety-nine dollars, Atlas Sports Genetics, a direct-to-consumer genetic screening company, tests a fetus to determine whether the child will be a sprinter or a marathon runner. They are probably making a lot of money.
Can we genetically design a child’s intelligence? There are thirty-three genes that can be altered to improve the intelligence of a mouse. Each one of these genes governs a different aspect of intelligence. Researchers at the University of Texas reported that cyclin-dependent kinase 5 governs learning and synaptic plasticity via control of NMDAR degradation. (Hawasli 2007)
There are genes that regulate the difference between the self and foreign organisms. Can they be used to predict whether a person is likely to accept an organ donation?
There are genes that enhance spirituality. Swedish researchers reported that genes encoding for AP-2 beta and the Serotonin Transporter are associated with “personality character spiritual acceptance.” (Nilsson 2007) When performing PGD, can we make certain that our child will be frum?
On the contrary, adultery genes have been discovered. A fascinating experiment was performed on two types of prairie dogs. One species is monogamous; its males mate with only one partner for their whole lifetime. The other species is polygamous. An “adultery gene” was found and isolated by Genesis Biolab’s “Ruthlessness/Bonding” Gene Test. This gene was removed from a polygamous prairie dog and transplanted into a monogamous one. The converse was done, too. The gene controlling monogamy was removed from a monogamous prairie dog and inserted into a polygamous prairie dog, influencing it to become a faithful mate. (Turner 2010)
The closest human counterpart to this gene is the MHC gene. There is a company now that sells infidelity DNA test kits, but there is no clinical evidence to assess its accuracy.
Legitimate studies, though, have analyzed truly faithful couples and found that the two partners have opposite MHC genes. Couples with the most similar MHC genes were more likely to have adulterous affairs. (Garver-Apgar 2006)
Should prospective marriage partners demand this type of genetic testing from one another before making their decision to become engaged?
We have seen that genetics are acknowledged in the Torah. The Talmud recognizes the importance of genetics. For example, Yevamot 64b advises against marrying into a family of lepers or epileptics.
More importantly, Torah education influences behavior. We learn this from Nahmanides’ commentary on Genesis 8:21:
…the inclination of man’s heart is evil from his youth.
A baby, Nahmanides points out, is egocentric and selfish. The child’s good inclination comes into play only after thirteen years of learning Torah and hesed (loving-kindness) from his parents. This moral education mitigates the child’s egocentricity and affects the balance of the evil and good inclinations. At the age of thirteen, the child is ready to observe the commandments of Torah, if he has received the right type of upbringing. For girls, this age is twelve.
The halakhic imperative is clear from this. Research in genetics should be based not on what we can do but on what we should do. Albert Einstein said:
Concern for man himself and his fate must always form the chief interest of all technological endeavors…in order that the creations of our minds shall be a blessing and not a curse to mankind.
Using the Torah and our halakhic authorities to guide us, we have the capacity to answer challenges and overcome genetic obstacles for the good of humanity.
Fox, B.H. 1995. “The role of psychological factors in cancer incidence and prognosis.” Oncology-Huntington 9:3, pp. 245-252.
Garver-Apgar, C.E., S.W. Gangestad, R. Thornhill, R.D. Miller, and J.J. Olp. 2006. “Major histocompatibility complex alleles, sexual responsivity, and unfaithfulness in romantic couples.” Psychol. Sci. Oct., 17:10, pp. 830-835.
Hawasli, A.H., D.R. Benavides, C. Nguyen, J.W. Kansy, K. Hayashi, P. Chambon, P. Greengard, C.M. Powell, D.C. Cooper, and J.A. Bibb. 2007. “Cyclin-dependent kinase 5 governs learning and synaptic plasticity via control of NMDAR degradation.” Mat. Meurpsci. Jul., 10:7, pp. 880-886.
Mahowald, M.B., M.S. Verp, and Anderson, R.R. 1998. “Genetic counseling: clinical and ethical challenges. Annual Review of Genetics 32:1, pp. 547-559.
Nilsson, K.W., M. Damberg, J. Ohrvik, J. Leppert, L. Lindström, H. Anckarsäter, and L. Oreland. 2007. “Genes encoding for AP-2beta and the serotonin transporter are associated with the Personality Character Spiritual Acceptance.” Neurosci. Lett. 16 Jan., 411:3, pp. 233-237. Epub 22 Nov. 2006.
Turner L.M., A.R. Young, H. Römpler, T. Schöneberg, S.M. Phelps, and H.E. Hoekstra. 2010. “Monogamy evolves through multiple mechanisms: evidence from V1aR in deer mice.” Mol. Biol. Evol. 27 Jun., 6, pp. 1269-1278. Epub 22 Jan. 2010.