Behavioral Genetics: The Quest for an Ethical Genome
John D. Loike,
Ph.D., Moshe Tendler, Ph.D.
Case Vignette #1
In his last days of life, Reuven’s father confessed to his son the
difficulty he had controlling his violent outbursts that resulted in physical
abuse of Reuven’s mother and older brothers. He advised Reuven to do whatever
possible to overcome what he feared was a genetic tendency. This confession
frightened Reuven because he also had difficulty controlling his temper. Reuven has read the recent studies from the
National Institutes of Health that a gene, called the L version of MAO-A,
affects neural circuitry in specific regions of the brain and influences the
tendency for violent behavior.[1]
Reuven and his wife of two months, Sarah, want to have “normal” children and
are planning to engage in preimplantation genetic screening (PGSc) to select an embryo that does not carry those genes
reported to predispose violent behavior.
Case Vignette #2
Leah and Ethan are committed to Orthodox Judaism but have parents who are
atheists and do not observe the religious tenets of Judaism. Leah and Ethan
have been married for 4 years and unlike Reuven and Sarah, they have had
fertility problems. After their physician suggested that they undergo In Vitro
Fertilization (IVF), Leah and Ethan want to use PGSc
to select an embryo that possesses genetic elements that are reportedly
associated with high spirituality. They have read the numerous reports on the
web[2]
and the cover issue of October 17th 2004 Time Magazine[3]
that the “God gene”, VMAT2, reportedly plays an important role in expressing
human spirituality. Leah and Ethan want to select children with a greater
tendency to accept an Orthodox way of life as opposed to the atheistic life
style of their grandparents.
How should halachic authorities respond to the plans and needs of these
two families? Specifically, would halachic authorities permit genetic
intervention to alter normal psychological, educational, and environmental
forces that control behavior? The innate role of genetics in human behavior is
recognized by the Torah. For example, the physical characteristics of Esau at
birth were an omen of his murderous tendencies.[4]
Moreover, the Talmud[5]
discusses how inborn behavioral determinants influence moral behaviors of
individuals.
This paper first outlines the general scientific principles of PGSc and the rabbinic response that focuses on the use of
PGSs to prevent the transmission of genetic diseases. The paper will then
discuss halachic considerations in the potential use of PGSc
to select embryos that contain genes or gene variants associated with
behavioral enhancement.[6]
Finally, this paper address new biotechnologies that are in development that
may offer couples halachic options to better ensure that their children do not
have severe or lethal genetic diseases.
The Science of PGSc
PGSc is a multistep process involving ovarian
stimulation, egg extraction, In Vitro Fertilization (IVF), cell biopsy, genetic
analysis, and embryo transfer (see a short video of this in reference[7]). It
is a powerful technology that can be used to screen preimplanted
embryos for the genes responsible for severe illnesses and lethal diseases.
The first step in this process involves hormonally stimulating a woman
to obtain 10-20 mature human eggs. The infertility physician then uses various
methods (e.g., intracytoplasmic sperm injection)[8] to
fertilize each egg with the husband’s sperm. In this way all the human eggs
from the woman are fertilized and allowed to divide in the laboratory into an
eight-stage embryo. The eight-cell embryo is then placed under a microscope,
immobilized, and one or two cells are gently detached from each embryo without
harming the other cells and without affecting potential future fetal
development of the embryos.[9] The
DNA from the cells obtained from each embryo are genetically screened within
24-48 hours, to assess which embryos express the specific inherited and
diseased genotypes and which do not. Once the genetic profile of each embryo is
established, one or two of the screened embryos that do not express the
“defective genes” are transplanted back into the woman’s uterus[10] to
allow for normal fetal development. PGSc is being
used by more married couples with a family history of genetic diseases in part
because this technology is extremely effective and because these procedures are
relatively simple to implement. In 2007 alone, over a thousand healthy babies
were born using PGSc.[11]
PGSc is not only used by families with a history
of a severe genetic illness. Parents with genetic-based disabilities, such as
deafness and dwarfism, have used PGSc to select for
children that have similar disabilities or conditions because they feel
they are better able to bring up children with disabilities like
themselves. One study reports that three
percent of infertility clinics surveyed have enabled couples to use PGSc to select for those kinds of disabilities.[12]
Some families use PGSc to have a baby who is an
immunological match for an existing seriously ill child in order to use the new
baby's cord blood for stem cell transplantation. PGSc
also can be used to select the sex of an embryo — either to avoid a genetic
disease caused by a mutation on the X chromosome (X-linked disease) or simply
to satisfy the gender preferences of the future parents. In 2005, PGSc clinics reported that 9% of their cases were done for
nonmedical sex selection.11 Recent advances in the genetic screening
of pre-implanted fetal cells and post-implanted fetal cells have enabled
geneticists to interrogate the human genome in ways never imagined fifty years
ago. Specifically, these genetic technologies have been used to identify three
broad categories of gene alterations.
The first category includes gene alterations inherited
in a Mendelian fashion that cause severe, and even lethal diseases, such as Tay
Sachs, cystic fibrosis, muscular dystrophy, or Fragile X syndrome that occur
early in life.[13] PGSc may also be used to screen for genes that cause
diseases that are expressed late in life such as Huntington’s disease and
certain types of Alzheimer’s disease. The second category includes gene
alterations that may not directly cause a disorder, but increase the
probability that an illness will occur at some point in the life cycle.
Examples in this category are genes associated with autism, diabetes,
atherosclerosis, heart disease, and various cancers.[14] The
third category includes gene alterations that influence behavioral and/or
physical traits of a person such as violence, spirituality, intelligence, body
stature, hair color, eye color, sexual orientation, promiscuity, or
athleticism. We refer to this third category as behavioral/physical trait
enhancement genes.
Screening the genes of preimplanted embryos
via PGSc is not 100% accurate.[15]
There are several reasons to explain how an embryo identified as healthy, by PGSc, can produce a child with an affected genetic disease.
Sometimes, this can occur by a biological process called genetic mosaicism,[16]
which denotes the presence of two populations of cells with different genotypes
in one embryo that developed from a single fertilized egg. Mosaicism may result
from a mutation during development that is propagated to only one subset of the
adult cells. Therefore, assessing one cell of an embryo may not reveal, with
100% accuracy, the genetics of the other cells of the preimplanted
embryo. To overcome these errors in screening, many infertility centers will
also test the DNA of the polar bodies of the mature egg. [17] The
polar bodies contain genes and chromosomes that the egg expels (the underlying
technology used to assess the genetics of a polar body in PGSc
is beyond the scope of this paper[18]). In addition, most infertility centers recommend
that a woman undergoing IVF and PGSc employ fetal
monitoring during pregnancy, including amniocentesis and chorionic villus
sampling (see a short video of this procedure in reference #[19])
to ensure that the implanted fetus does not express the defective gene.
However, for religious families, amniocentesis and chorionic villus sampling
are generally not done because aborting a diseased fetus is not an halachic
option. Most halachic authorities do not permit the termination of pregnancy
after the embryo has gestated for longer than 40 days (approximately 6-7 weeks
using the conventional classification of gestation).[20]
There are medical risks associated with PGSc
that need to be evaluated. In general, these risks are related to the hormonal
ovarian stimulation that the woman must undergo in order to obtain mature eggs.
Hormonal hyperstimulation of the ovaries is necessary to generate eggs that are
ripe for fertilization. This process involves a seven to ten day regimen of
medications[21]
that are similar to hormones that a woman produces during her menstrual cycle
and pregnancy, but given in much larger doses. These prescribed hormones are
self-injected to stimulate the woman to simultaneously produce 10-20 mature
eggs from her ovaries.[22]
Without these medications, most women will only produce one mature egg per
month during a menstruation cycle. Women undergoing hormonal hyperstimulation
have their blood hormone levels regularly monitored, their temperature
monitored daily, and undergo periodic ultrasound assessment of their ovaries.
These tests indicate when the eggs in the ovaries are ripe for egg retrieval.
When mature eggs are detected, the woman is given a light anesthesia, and the
eggs are collected using a thin needle that is guided through the vaginal wall
by ultrasound.
While only a few percent (3-10%) of the women experience some sort of
medical problems with hormonal hyperstimulation, it is still important to
delineate all the known medical risks. For example, this procedure can produce
ovarian hyperstimulation syndrome (OHSS) in the woman, which can cause
life-threatening complications including blood clots, kidney failure, shock,
and fluid buildup in the lungs. In a small number of cases, women experiencing
OHSS might need to have their ovaries removed.[23]
Clinical experience of infertility experts indicates that women, who undergo
hormonal hyperstimulation for the first time without complications, will rarely
experience complications in future hormonal hyperstimulation treatments.
However, women engaging in multiple cycles of hormonal hyperstimulation
of the ovaries may be at increased risk of breast or ovarian cancer.[24] The
link to an increased cancer risk has not been firmly established but it is
important for reproductive specialists to study the long-term effects of
fertility drugs now that their use is so commonplace in IVF practice. Even
though over 3.5 million babies have been born via IVF as of 2008, there are
only a few studies in the literature that report the incidence of cancer in
women who have had repeated cycles of hyperstimulation of the ovaries.[25] It
is important to recognize that researchers have had only about a decade to
study the potential risk of cancer in a significant numbers of women who have
had hormonal hyperstimulation, since these cancers often do not appear until
ages 50 or 60. However, the unknown
potential cancer risks and the chance that IVF – generated siblings will marry
each other, has led many infertility centers to limit hyperstimulation of a
woman to 5-6 times in her lifetime.
There are also short-term, but even less common, medical risks associated
with the surgical procedures and anesthetics involved in IVF and egg retrieval.
These risks include an increase rate of infections, hemorrhage, and
psychological effects. While the incidence of these short-term and long-term
medical risks vary from clinic to clinic, infertility clinics claim that most
women undergoing these procedures do not experience these medical risks and the
babies produced by either IVF or PGSc are almost
always healthy.[26]
Future technologies are emerging that might eliminate the need for women
to undergo ovarian hyperstimulation and further reduce many of the medical
risks associated with PGSc. For example, scientists
are becoming more proficient in retrieving immature eggs from hormonally
unstimulated women and subsequently, maturing the eggs in the laboratory.[27]
Currently, the success rate of producing a child using immature eggs is
significantly lower than using mature eggs. Hopefully this rate will improve in
the future. Overall, the success rate of producing a child using current IVF
technologies is higher with younger women and in clinics that have a high
volume of patients.[28]
Most of the major clinics in the United States and Israel report a clinical
pregnancy rate per IVF procedure of about 30-40%. The medical risks to the IVF/PGSc generated child appear to be minimal but more studies
are being done to examine this aspect in greater detail.
Halachic permissibility of engaging in PGSc in
couples with a history of hereditary diseases.
Most halachic authorities in the United States and in Israel allow PGSc when a family’s genetic history indicates a risk of
having a baby with a genetic disorder (screening of gene variations that
directly causes disease – see page 16). There is no difference whether the
embryo is screened for a genetic disease that will affect the child in his or
her early years, such as Tay Sachs or late-onset diseases such as Huntington’s
disease, Alzheimer’s disease, or diabetes. In all such cases, halacha will
allow married couples to use PGSc to select an embryo
that does not contain the heredity determinants that causes these diseases.
There are few halachic responses discussing the use of PGSc
to select embryos that do not express gene variations in category two, (i.e.,
gene alterations that are associated with an increased risk of disease). It
seems appropriate that when there is a family history of such category-two gene
variants, PGSc may be an acceptable medical procedure
when the relative risks and benefits are properly evaluated.
In Judaism, the use of PGSc in preventing or
reducing the likelihood of genetic diseases is a moral imperative as is the
treatment of an illness.[29] An
important philosophical concept related to the obligation to heal is found in
Bava Batra 10a. Rabbi Akiva states that human beings do not prevent Divine
intent when they help the poor or to heal the sick. In Judaism, human beings
are directed to partner with God to improve the world.[30]
Genesis Rabba 11:6 states that a philosopher asked Rabbi Hoshaya
for the reason for circumcision. Rabbi Hoshaya
responded saying that God did not create either the world or human beings in a
perfect state and as a result, human beings can partner with God in the
creation process.[31] Ramban further
states that the God-human partnership is reflected in the Bible’s use of the
phrase “and have dominion” that charges the human race to use scientific
knowledge and technologies to improve the world.[32]
Finally, this theme is incorporated by several mussar
authorities—the Zohar and Peskei Rabbati—who
suggest an alternate translation of the Kiddush blessing (Genesis 2:1-3) said
every Friday night.[33] The
classical translation of Genesis 2:3 states, “And God blessed the seventh day,
and hallowed it”; because that in it He rested from all His work “asher bara elokhim la’asot (which God had created – to do).” The alternate translation of the word la’asot is that it is the responsibility of human
beings, not God, “to do”—to complete the doings of his creation (tikkun olam). The use of science and medicine in the service
of humankind is a fulfillment of this Divine mandate.
There are also many halachic sources that support a mandate to practice
proper health measures and prevent illness. Rambam,[34] and
Tur,[35]
both cite the verse in Deuteronomy (4:9): “Duly take heed to yourself and keep
your soul diligently” as the biblical directive to preserve health.[36]
Protecting a child from illness can be classified under the rubric of the moral
obligation to preserve health and to prevent illness.[37] Netziv[38]
applies this halachic principle to the infertile couple in his analysis of the
descriptions in the Torah about the infertility of Sarah, Rebecca, Rachel and
Hannah. For example, Rachel declared to Jacob: "Give me children,
otherwise I would rather die."[39] Netziv explains that this statement signifies that
infertility can be viewed as a critical disease.[40]
Halacha also recognizes that there is a predisposition to genetic
disease and warns the individual not to marry someone from a family with a
history of genetic disease. Yevamot 64b and several
halachic works[41]
states that one should not marry into a family of lepers or epileptics. Rashi
expands this category to include any hereditary disease.[42] This warning certainly means that individuals
should also not create families with genetic diseases. In the past, some
halachic authorities advised couples who are both carriers of genetic diseases
such as Tay Sachs to divorce.[43]
However, this response was written before PGSc was fully developed in the 1990s. Today, married
couples who are carriers of genetic diseases can have healthy children and
should consider PGSc as a mandatory procedure to
preserve health and avoid producing a child or family with a severe genetic
illness.
Halacha does not demand that an infertile couple engage in ART (artificial
reproductive technologies) and expose themselves unnecessarily to known and
unknown health risks.[44]
However, a modicum of medical risk may be assumed by a couple to fulfill the
biblical commandment to procreate (pirya v’rivyah).[45]
Since PGSc has been demonstrated to be so successful
in generating healthy children from couples who are both carriers of genetic
diseases, there is an obligation for families with a genetic history of disease
to utilize PGSc to produce healthy children and not
to create a family with genetic diseases. In addition, if a strong emotional
bond exists between two individuals who are both carriers for a genetic disease
such as Tay Sachs or cystic fibrosis, they may still marry because they have
the option to use PGSc to produce healthy children.
However, such a couple should consult a rabbinical authority before they marry
to discuss the halachic and medical consequences of a long life that requires
the use of contraception.
There are other potential halachic considerations associated with PGSc related to moral status of the unused and
non-implanted embryos. Normally, non-implanted embryos that carry defective
genes are discarded by most fertility clinics. Is this halachically acceptable?
An artificially produced microscopic embryo comprised of 8 cells created
outside a woman’s body does not have the equivalent moral status of an
implanted human embryo or fetus. However, even an embryo that has developed for
less than forty days is not halachically insignificant. Ramban,
states that one may engage in melachot on
Shabbat to save a fetus that is even one day old.[46]
However, many halachic authorities state that an embryo that has gestated less
than 40 days can be terminated if there are compelling maternal medical
concerns. Most halachic authorities permit discarding non-implanted embryos
carrying genes that either cause disease or are highly associated with
increasing the likelihood of a disease.
Another halachic consideration in PGSc is the
Biblical injunction against masturbation or “wasting of male seed”. Men who are
being tested for infertility must provide semen
for fertility analysis. The halachic issue associated with procuring semen has
led religious professionals to establish a hierarchy of preferred methods of
diagnosing infertility. Today, since 50% of all infertility is caused by male
infertility, the first medical test that should be done is a post-coital
examination where a fertility physician removes cervical fluid from the woman
the morning after the couple had marital relations to assess sperm density and
motility. If the man’s sperm appears normal, it may still be necessary to
assess his seminal fluid by use of a specially designed condom that does not
injure the sperm or affect the seminal fluid composition. Only as a last resort
would halachic authorities allow the physician to mechanically or electrically
stimulate the man to obtain semen or allow him to self-masturbate into a
receptacle for semen collection. In addition, semen may be procured during
relations and cryopreserved under conditions when artificial insemination has
to be done at a time when intercourse is prohibited by Jewish law (when the
woman is in a state of ritual impurity). Consultation between the infertility
specialist, the couple, and their rabbi is essential
in determining which method of sperm procurement would best apply to the needs
of the specific couple undergoing IVF and PGSc.
Since timing is a critical element in the whole process of IVF and PGSc (especially procuring mature eggs from the woman),
careful planning should be employed to avoid scheduling medical procedures on
Shabbat or religious holidays (Yom Tov).
However, if such appropriate scheduling cannot be accomplished, then it is
permissible to engage in these medical procedures on Shabbat and Yom Tov using a gentile physician who is
not governed by the laws of Shabbat and Yom Tov.
PGSc for non-medical reasons
There are situations in which halachic authorities have deliberated the
use of PGSc for non-medical conditions.[47]
Some rabbis[48] have
allowed couples to engage in PGSc in the non-medical
situation where an infertile husband is a kohen (of the priestly tribe), and
donor sperm is used to produce a child. The husband and wife may choose IVF to
select a female embryo to avoid the social consequences of a kohen whose son is
not a kohen.[49] If
sex selection were not employed, this scenario might cause embarrassment to the
couple and would violate the family’s right to privacy since the couple’s
friends and community would recognize that the baby boy born from the woman is
a product of IVF using donor sperm. This example is one in which some Halachic
authorities rely on specific humanitarian reasons in allowing PGSc for sex selection.[50]
There is virtual unanimity of rabbinical authorities in prohibiting the use of PGSc just for sex selection.[51]
However, in couples where PGSc is necessary to select
an embryo that does not carry a genetic disease it is permissible at the same
time to select the gender from the pool of “healthy” embryos.
Another important halachic consideration with respect to sex selection
is summarized by the Rambam[52]
where he states that the Biblical duty to procreate and give birth to at least
one son and one daughter is fulfilled when one engages in marital relations
until children are produced. There is no obligation for a couple to engage in
heroic medical interventions to produce a child,[53]
much less to select the gender of a child to fulfill the biblical mitzvah of
procreation. Engaging in marital relations is within the power of human beings
but the gender of the child rest in the hands of God. The birth of both a son
and daughter only signifies a point in time when the mitzvah of procreation has
been fulfilled.
In countries where the government limits the number of children, there
is an increased tendency to utilize various means to produce more boys than
girls. For example, the boy to girl ratio in some countries is approaching 120
boys to every 100 girls born. This creates an unnatural biological environment
where there are not enough girls for marriage. Such a situation must not be
allowed to develop within the Jewish community.
PGSc for genes that affect behavior
There are many reasons why it may be halachically and medically
inappropriate or illogical to use PGSc to select
embryos with specific behavioral traits:
A panoply of genes influences behavioral traits. Screening for one or two gene alterations
undermines the complexity of this whole process and fails to take into account
the scientific evidence that environment is a critical component in shaping
behavior. Judaism believes that all individuals have behavioral tendencies that
may cause them to sin. Moreover, God created all individuals with the ability
to overcome inappropriate behavioral urges. Thus, for most Jews there is no
medically compelling reason to utilize PGSc to select
embryos with enhanced behavior traits. Nonetheless, it is critical for halachic
authorities to consider those rare instances where one or both parents express
an abnormal behavioral trait such as violence (documented by psychological
testing) and a family history of violent behaviors. Under those conditions, PGSc would be an appropriate procedure when empirical
medical data confirms that selecting those embryos lacking those specific genes
would in fact dramatically reduce the violent tendencies in the offspring. At this time, there is no reported evidence
that PGSc would in fact select for embryos that will
grow up being less violent or would develop into more religiously committed
Jews. Therefore, as of 2009, it is inappropriate and halachically improper to
engage in IVF/PGSc to select for behavior enhancement
traits. Equally important, halachic authorities would prohibit the use of a “full service” fertility clinic, such as
fertility institutes, that encourages couples to sign up for embryo screening
to choose the gender, eye color, hair color, and complexion.[54]
Historical and scientific evidence highlight the effectiveness of
environment in overcoming many of the unwanted behavioral traits. Judaism
places a high value on the impact of education and environment (family life,
school, and community) in helping to mold the moral character of a child.
Therefore, the first line of defense to combat undesired behavior is to
properly educate the child in the ways of the Torah and to create an
environment to help the child learn to control normal biological urges.
Resorting to PGSc will not exempt the parents from
the obligations to educate their children about proper moral conduct.
While the moral status of preimplanted embryos
are not equal to that of a 40 day old implanted fetus or a child at birth,
nonetheless, such embryos should be treated respectfully and not wasted
unnecessarily because they do have the potential to create human life.
Therefore, unused non-implanted embryos should not be discarded but rather
cryopreserved, or donated to other couples. If this is not feasible then they
should be donated for medical research.
Finally, there is an important societal, biological, and medical concern
that wide scale embryo screening for behavioral enhancement traits could affect
genetic diversity, a critical evolutionary element of human development. Such
genetic manipulations, even if restricted to local communities, could render a
population more susceptible to unknown or emerging catastrophic infections and
other disorders that may be enhanced by the very DNA sequences associated with
the behavioral genes being selected.
Analysis of the Two Case Vignettes
In analyzing the two cases presented in the beginning of this article,
halachic authorities might only allow Reuven and Sarah to utilized PGSc only under specific conditions. If genetic analysis of
Reuven establishes a clear and significant correlation with psychological
testing that confirms his violent tendencies and documentation that he has
already engaged in as abusive acts then Reuven and Sarah would be allowed to
use PGSc.
With respect to Leah and Ethan, if they were using PGSc
to select an embryo that did not have the gene for a medical disease such as
Tay Sachs, then they would be permitted to select from a pool of “healthy”
embryo for one that also expressed gene variations associated with high
spirituality and they could also select the gender of the baby from this pool.
However, halachic authorities would not permit the use of PGSc
solely for behavioral trait enhancements in situations where there is no family
history or genetic predisposition to disease, even if the association between
genetics and spirituality could be proven scientifically.
Future Technologies
DNA, science, and some elements of halacha are all liable to change in
response to internal and external events.
Scientific principles change as more research is generated to understand
the biology of life, disease and death. In contrast, the halachic process
provides established guidelines how and when halacha should respond to internal
religious demands or to external events such as emerging technologies. Halacha
recognizes that science and religion often collide, philosophically and
practically. Yet, the halachic process possesses intrinsic mechanisms by which
such collisions are transformed into practical applications.
Any discussion on genetic screening of pre embryos or embryos must
present emerging technologies that would require a re-evaluation of their
halachic ramifications. Currently several US medical centers, including
Columbia University College of Physicians and Surgeons are exploring a new
technology in which normal vaginal secretions can be collected into a modified
tampon from a woman who is less than 4 weeks pregnant. These vaginal secretions
contain cells that are shed from both the woman and the developing embryo. If
the embryonic cells can be separated from the maternal cells, they can be
accurately analyzed to genetically determine whether the embryo is affected
with a genetic disease such as Tay Sachs or cystic fibrosis. These tests can be
done within 24 hours after obtaining the sample and will provide the couple
with an affected embryo (less than 40 days old) the choice whether or not to
terminate the pregnancy. When this technology becomes more established it would
allow a pregnant woman, from a couple where both partners are carriers for a
genetic disease such as Tay Sachs, to genetically test the cells obtained from
the fetus. If the fetus has gestated less than 40 days and was found to have
either Tay Sachs or cystic fibrosis, then the couple should choose termination
to prevent the creation of genetically diseased children.[55]
Conclusions
In summary, our understanding of the genetic predisposition for
behavioral traits is in its early stages. The relative importance of genes that
are associated with behavioral traits such as spirituality, intelligence,
sexual orientation, or excessive violent behavior will require much more
research. This is especially important since environmental factors can play a
critical role in behavior. However, if this knowledge and technology does
develop credibility in the future, Halachic authorities would revisit the
issues presented above.
PGSc is continuing to improve as a means to
accurately assess whether a pre-implanted embryo carries common and less common
gene mutations or variants that would confer diseases such as Tay Sachs, cystic
fibrosis, Canavan disease, Gaucher disease, Familial dysautonomia, Niemann-Pick
disease, Fanconi anemia, Bloom syndrome, and Mucolipidosis
Type IV, and late onset diseases such as Huntington’s disease and Alzheimer’s
disease. The principle of chamira sakanta me'isura (a situation
of possible danger demands more stringency than in the case of a halachic
prohibition[56])
provides the appropriate incentive to engage in medical procedures, such as PGSc, in order to produce a healthy child, even though the
procedure may involves some potential halachic concerns. Since IVF and PGSc are relatively safe procedures, we would encourage
those rabbis who discourage an emotionally committed couple from getting
married if both are carriers for a genetic disease to re-evaluate their
halachic positions. These rabbis were concerned about the high probability of
two carriers to produce children with the affected disease. However, the
emerging success of IVF and PGSc in producing healthy
children affords a couple that carries the defective gene the option to marry and
produce healthy children.
[1] Frazzetto G, Di Lorenzo G, Carola V, Proietti L, Sokolowska E, Siracusano A, Gross C, Troisi A.
Early trauma and increased risk for physical aggression during adulthood: the moderating role of MAOA genotype. PLoS ONE. 2007;2(5):e486l; Beaver KM, Wright JP, DeLisi M, Walsh A, Vaughn MG, Boisvert D, Vaske J.A gene x gene interaction between DRD2 and DRD4 is associated with conduct disorder and antisocial behavior in males. Behav Brain Funct. 2007; 3:30; Viding E, Frith U. Genes for susceptibility to violence lurk in the brain. Proc Natl Acad Sci U S A. 2006;103(16):6269-74.
[2] http://www.uncommondescent.com/biology/the-god-gene/
[3] http://www.time.com/time/covers/1101041025/.
[4] Rashi Genesis 25:25.
[5] Babylonian Talmud Shabbat 156a.
[6] In order to simplify this discussion, we focus on couples in which sperm is obtained from the husband and the egg from the wife, thereby avoiding the halachic issues of maternity, paternity, and surrogate motherhood.
[7] Pre-implantation Genetic Screening (PGSc) is often referred to as Pre-implantation genetic diagnosis (PGD). The term preimplantation genetic screening is used to denote procedures that do not look for a specific disease but use PGD techniques to identify embryos at risk. Pre-implantation genetic diagnosis is a poorly chosen phrase because, in medicine, to "diagnose" means to identify an illness or determine its cause. An oocyte or early-stage embryo has no symptoms of disease. They are not ill. Rather, they may have a genetic condition that could lead to disease. To "screen" means to test for anatomical, physiological, or genetic conditions in the absence of symptoms of disease. Therefore, this paper uses the term Pre-Implantation Genetic Screening for what is commonly referred to as PGD.
[8] Intracytoplasmic sperm injection (ICSI) is often used in cases for PGD for single gene disorders, regardless of whether or not there is any evidence of male factor infertility. Using ICSI will avoid DNA contamination due to the presence of surplus sperm (and their DNA) in the embryo cultures.
[9]
For a short video showing this
process see:
http://www.youtube.com/watch?v=pocZGO8wJ38&feature=PlayList&p=1201525DBF541A14&playnext=1&index=2.
[10] In some cases the women are given progesterone or other drugs to facilitate their uterus to receive and retain the implanted embryo.
[11] Bruce Goldman, Reproductive medicine: The first cut, Nature 445:479-480, 2007.
[12] Baruch S, Kaufman D, Hudson KL. Genetic testing of embryos: practices and perspectives of US in vitro fertilization clinics. Fertil Steril. 2008;89(5):1053-8.
[13] Down’s syndrome can also be screened using PGSc but there is no evidence that there is a genetic predisposition (i.e. family history) for this condition.
[14] Geneticists also divide the first two categories into three subgroups. For example, in category one (gene alterations that cause severe or lethal illnesses), some of the conditions, such as phenylketonuria (PKU), are treatable that allow the individual to live a relatively healthy life. The second subgroup include disorders, such as cystic fibrosis, where treatments help maintain the health of the affected individual for decades but in the end these individuals will not have a normal life span. A final subgroup in this category includes disorders that are currently not treatable such as Tay Sachs, Fragile X, and Huntington’s disease. These three types of sub-grouping can also been applied to genes alterations of the second category –those genes that impact the probability of developing a disease sometime in one’s lifetime.
[15] As of 2008 there are only a few reports assessing human error in performing these genetic analysis but most laboratories engage in procedures to minimize inaccuracies due to human error. One study claimed that the risk for misdiagnosis due to allele drop-out or partial amplification relates directly to the type of genetic disorder for which testing is performed. The estimated risk of transferring an affected embryo mistakenly identified as normal by PGD is approximately 2% for recessive disorders and 11% for dominant disorders. Such errors can be reduced significantly if linked markers also are analyzed [see C.M. Lewis, T. Pinel, J.C. Whittaker and A.H. Handyside, Controlling misdiagnosis errors in preimplantation genetic diagnosis: a comprehensive model encompassing extrinsic and intrinsic sources of error, Hum Reprod 16 (2001), pp. 43–50]. The true risk for obtaining a clinically relevant false negative result can be determined only by further genetic testing of all conceptions after PGD, but no such studies have been reported as of 2009.
[16] Huang A, Adusumalli J, Patel S, Liem J, Williams J 3rd, Pisarska MD. Prevalence of chromosomal mosaicism in pregnancies from couples with infertility.Fertil Steril. 2008.
[17] Some infertility and PGSc clinics will remove two cells from the embryo to decrease the risk or error.
[18] Renbaum P, Brooks B, Kaplan Y, Eldar-Geva T, Margalioth EJ, Levy-Lahad E, Altarescu G.
Advantages of multiple markers and polar body analysis in preimplantation genetic diagnosis for Alagille disease. Prenat Diagn. 2007 Apr;27(4):317-21. See http://www.pgd-baby.com/pgd-process.html, http://www.care-life.com/embryo_screening.htm
[19] See http://www.youtube.com/watch?v=0XUZsvTkEnw for a short video showing this technique.
[20] Steinberg, Avraham, Enclyclopedia of Jewish Medical Ethics, (Feldheim Publishers, Jerusalem, Israel, 2005) pgs, 422,571-586.
[21] Medications include one or more of the following hormones: gonadotropin-releasing hormone, follicle-stimulating hormone, human menopausal gonadotropin, and human chorionic gonadotropin.
[22] Tarlatzis BC, Bili H. Safety of GnRH agonists and antagonists. Expert Opin Drug Saf. 2004 Jan;3(1):39-46.
[23] http://www.health.state.ny.us/community/reproductive_ ealth/infertiliy/eggdonor.htm
[24] Some scientists believe this link is associated with infertility and not ovarian hyperstimulation.
[25] atz D, Paltiel O, Peretz T, Revel A, Sharon N, Maly B, Michan N, Sklair-Levy M, Allweis T.
Beginning IVF treatments after age 30 increases the risk of breast cancer: results of a case-control study. Breast J. 2008 Nov-Dec;14(6):517-22.
[26] ttp://www.medicalnewstoday.com/articles/139400.php
[27] Rao GD, Tan SL. In vitro maturation of oocytes. Semin Reprod Med. 2005, (3):242-7; Suikkari AM, Söderström-Anttila V. In vitro maturation of eggs: Is it really useful? Best Pract Res Clin Obstet Gynaecol 2007; 21: 145–155.
[28] As women age, fewer mature eggs can be produced via ovarian hyperstimulation and the rate of embryo implantation also decreases.
[29] Maimonides, M., Mishnah Commentary on Nedarim 4:4 and Nedarim 38b. The Biblical verse "and heal he shall heal" [Exodus 21:19.] is interpreted by halachic authorities from Talmudic times to mean that authorization is granted by God to the physician to heal. In fact, the Rambam following the discussion in the Talmud, states that the law of restoring lost property includes also the restoration of health. If a person has "lost his health" and the physician is able to restore it, he or she is Biblically mandated to do so.
[30] Sa'adiah Gaon, in his Arabic translation of the Torah, explains the term "God's image" as meaning the ability to conquer and rule. Just like G-d rules over all of creation, man rules over the animal world.
[31] Sefer Hachinuch on circumcision.
[32] See Ramban on Genesis 1:28
[33] Pesikta Rabbati 94.
[34] Mishna Torah Rotzeach 11:4.
[35] Shulchan Aruch Chosen Mishpat 427:8.
[36] Steinberg, Avraham, Enclyclopedia of Jewish Medical Ethics, (Feldheim Publishers, Jerusalem, Israel, 2005) pg 830-834
[37] Tendler MD. Responsa of Rav Moshe Feinstein. New York: Ktav, 1996, p. 57.
[38] Natziv Shiltos, Parsha Naso.
[39] Genesis 30:1.
[40] Rashi on Genesis 30:1.
[41] Mishneh Torah, Hil. Issurei Biah 21:30; Shulchan Arukh, Even Ha-Ezer 2:7;Chatam Sofer 137; Peri Hasadeh part 2 #26; Chazon Ish Yorah De’ah 152;2.
[42] Rashi on Yebamot 64b
[43] Rabi Y Zilberstein, Halacha U’ Refuah Vol 2, 5741 (1981) pg 111.
[44] Does the principle that under certain circumstances God will “protect the simple” (Shomer petayim Hashem -Psalms 116:6) discharge Jews from taking a proactive medical stance? In fact, the underlying philosophy of shomer petayim Hashem is often misunderstood. Avodah Zarah (30b) states that "R. Eliezer claims that one may eat grapes or figs at night and need not fear [that a poisonous snake had bitten into them], for it is written, Shomer petayim Hashem." A similar concept is found Niddah (31a): "We have learned [that] if one has relations with his pregnant wife on the 90th day after conception, it is as if he were killing [the fetus]... Abbaye says: 'He may act normally (e.g. engage in marital relations), because of the dictum shomer petayim Hashem.'" The Tosefot Rid (Avoda Zarah 30b) derives an important insight from these Talmudic statements suggesting that the principle of Shomer petayim hashem applies only when the dangers are rare occurrences or unusual. Given that the permissibility of eating grapes and figs at night is based upon the principle of shomer petayim Hashem, the Tosefot Rid reveals that it was implemented only because the risk is rare. Rashi on Ketubot (39a) states that only if there is a minimal risk of danger then one may rely on shomer petayim Hashem, but if a safe alternative exists, one should not rely on shomer petayim Hashem. Ramban (Exodus 22:15) states that the term petayim refers to individuals whose intelligence is insufficient to understand various matters or understand concepts very superficially and whose hearts are easily misled. The Terumat HaDeshen (Chapter 211) goes so far as to claim that the principle of Shomer petayim Hashem does not apply to educated individual (i.e., talmidei chachamim). Therefore, when a situation is known to be hazardous and yet people regularly disregard it, shomer petayim Hashem might not apply. In the case of a couple where both members are carriers for a genetic disease such as Tay Sachs, there is a probability that 25% of their children will develop Tay Sachs and die within 6 years. This does not constitute a rare occurrence or a minimal risk and the principle of shomer petayim Hashem should not apply. Furthermore, there is a relatively safe and effective alternative available to eliminate that risk, namely PGSc that is recognized by fertility experts around the world. In addition, the principle of dashu bei rabim (the multitude are accustomed to it) presented in Shabbat 129b may allow individuals to assume known medical risks in order to achieve medical benefit. In contrast, smoking that was assumed to be of minimal medical risk in the 1960’s is now prohibited by Jewish law in view of all the established medical dangers of smoking.
See p. 45-47 of this JME issue -editor
[45] Steinberg, Avraham, Enclyclopedia of Jewish Medical Ethics, (Feldheim Publishers, Jerusalem, Israel, 2005).
[46] The Ramban (Torat ha-Adam, sha’ar ha-meihush, inyan sakkana) based this ruling on the premise that it is better to violate one Shabbat in order for the fetus to be saved to celebrate many shabbatot in the future.
[47] Rabbi Broyde also permits parents to utilize PGSc to have a child that genetically matches another family member who requires a bone marrow transplant. Broyde MJ. Pre-implantation genetic diagnosis, stem cells and Jewish law. Tradition. 2004.
[48] Ibid 20.
[49] If the couple did not utilize sex selection via PGSc, and had a boy, halachically the child would not be the son of a Kohen and would not be allowed to recite the Priestly Blessing, would not receive the Kohen aliyah and the parents would not be obligated to perform the mitzvah of redemption of the first born [Pideyon Haben- if the sperm donor were Jewish].
[50] There is also some controversy whether one is permitted to use PGSc to select an embryo whose cells obtained from the cord blood will be compatible to treating a sick sibling. See Nishmat Avraham (publisher: Schlesinger Institute, Jerusalem, new edition - 2007) vol. 4, Choshen Mishpat, 243:1.
[51] See Grazi, Richard V. Be Fruitful and Multiply; Fertility Therapy and the Jewish Tradition (Jerusalem:Genesis Jerusalem Press, 1994), pg 186.
[52] Moreh Nevuchim 15:1.
[53] Shabbat 31a.
[54] http://www.fertility-docs.com/index.phtml.
[55] Whether termination should be done via a dilatation & curettage or use of oral drugs requires the consultation with the couple’s rabbi and physician.
[56] Hulin 10a.