Genetics Essay, Research Paper
Genetics: Issues of IVF, screening, pre-selection, genetic testing, cloning and the social implications.
James Watson once said, ?We used to think that our fate was in our stars. Now we know that, in large measure, our fate is in our Genes? (Jaroff 1998).
On June 26th 2000, The Human Genome Project will unveil its rough draft mapping of the deoxyribonucleic acid (DNA) sequences within the human chromosomes (genetic code), to the public. The project has been ongoing since the late eighties, and is a huge international exercise, which has so far cost approximately 3 billion dollars. The final draft is expected to be complete by the year 2003 and the assumption is that it will have a massive impact on the path of human evolution! (Hamilton, 1998).
Although we like to think that we are much more than the sum of our genes, our genes in large measure determine our abilities, our preferences, and our emotions (Berkowitz, 1996). This essay will look at the contemporary issue of genetics; it will examine its role in Assisted Reproductive Technology (ART) and how it is utilised for screening purposes in both in vitro fertilisation (IVF) and the diagnosis of disease. This essay will also discuss the ethical issues of sex/gender pre-selection, cloning, and the use of genetic testing for social purposes. These issues may have an enormous impact on whole families and the future of our children. Appleyard (1999) suggests that any forecast of the future must make one of two assumptions, either we manage this deeper genetic knowledge wisely or we do not. In the first case, we can be reasonably optimistic. In the second case, there need be no limit to our pessimism.
Genetics is a science, and the scientists are both influencing and influenced by contemporary culture. Therefore, the issues of genetics are framed in a response to current medical, social and political concerns. Nature has provided humankind with a way of reproduction since humans walked the earth. It has only been in the last thirty years, that scientists have learned to understand the complex processes involved in conception, and more recently, to manipulate them. Science has the techniques that can overcome natural infertility, and attempt changes in the genetic make-up of the babies that are desired. (Challoner, 1999)
In vitro fertilisation (IVF), where sperm and egg are brought together in a glass dish in the laboratory, is a term society has grown to use over the years. However, in recent years, this technology has exploded in all directions; into areas that were once consigned to the mind of the science fiction writer. On the 25 July 1978, the first ever human was born, having been conceived outside of the mother?s body. Her name is Louise Brown and her very existence heralds the pioneering techniques of Professor Robert Edwards and his colleagues. (Challoner, 1999). However, no other subject in medical science receives more critical attention from both government and the media than reproductive biology and genetics. The research on human embryos created by IVF is considered by some critics to be the most disturbing of all, and although science believes it is never undertaken lightly, and even helps researchers to understand why most embryos fail to thrive or are prone to abnormalities, many countries have forbidden such research. (Gosden, 1999).
For example, Wilkie (1998) noted that in 1998, a moratorium was called in Switzerland, concerning the creation of genetically modified organisms, but in this instance the country voted against a total ban. In Britain, the Human Fertilisation and Embryology Act (1990) permits embryo research under licence, but only for up to fourteen days after fertilisation. In Britain alone, more than 30,000 babies have been born as the result of IVF, (Challoner, 1999) and for couples who are desperate for children of their own but are otherwise unable to have them, successful IVF brings a course of profound satisfaction.
Whether a child is conceived via natural or IVF methods, the issue of screening is always at the forefront of any parent or health practitioner?s mind. The last two decades have seen a massive increase in the use of prenatal diagnosis. Some form of screening or testing is now offered routinely to every pregnant woman in the UK.
Prenatal diagnosis and screening is often presented as a routine part of antenatal care, but in fact it raises significant ethical dilemmas that need to be addressed. Prenatal testing and screening allows foetuses with varying degrees of disability or lethal conditions to be identified, (BMA 1998).
According to the BMA (1998), this prenatal genetic screening has been offered by health authorities in the UK for over twenty years. It is frequently used as a means of identifying those at a higher than average risk of having a child with a disability so that the parents may be offered genetic testing to give more specific information about the health of the foetus and define the risk for future pregnancies. Prenatal screening might be by family history, serum screening, molecular tests, or ultrasound. Ultrasound scanning is currently offered routinely to all pregnant women in the UK and, although it is undertaken to monitor the development of the foetus, it can detect both major and minor defects.
Often genetic screening is offered as ?routine? with an assumption that all women will accept it. There is a fear that some women may accept screening unquestioningly, without considering the implications of the information that will be made available. Any decision about whether to opt for prenatal screening or genetic testing must be based on good quality, objective information. Marteau (1995) emphasises both the ethical and the psychological necessity of such information being provided. Medical ethics generally assumes that encouraging informed decision-making helps protect the individual sense of self-determination. Psychologically it helps to prepare women for different outcomes and thereby protects their overall psychological wellbeing. For example Smith et al (1994) found that only one third of the women offered serum screening for Down Syndrome understood that a negative test did not necessarily mean that their child would be healthy. This problem of obtaining ?informed consent? is likely to become more complicated for patients and health professionals alike, as it becomes possible to test for many different disorders with a single procedure.
Not all people having genetic tests are those identified as at increased risk by genetic screening. Some people will already know that they are at increased risk of passing on a genetic disorder from a previous affected pregnancy, from other family history, or from a genetic test undertaken on one or both of the parents. If both parents are known carriers of a recessive disorder, or if the woman carries the gene for an X-linked disorder or if either partner carries the gene for a dominant disorder, any future child will be at risk. Some of these people will opt for pre-natal genetic testing (Harris 1998).
It has been suggested that discussion of prenatal testing by expert health professionals may imply to the patients that it is necessary, desirable, and in the best interests of the future child and that, it should be accepted. Green and Statham (1996) noted that an important distinction between the views of obstetricians and patients about prenatal diagnosis is that the obstetricians saw the tests as a way of detecting abnormality, whereas parents saw them as offering reassurance. It is likely that this desire for reassurance influences many people?s decisions to undergo both screening and diagnostic tests and that they expect a favourable result, which can make it more difficult to cope with when an abnormality is detected. The British Medical Association (1998) suggest that it is important that pre-test counselling for genetic testing should include discussion of the worst case scenario, so that the patient is aware of the possible outcomes and has been able to consider them carefully before deciding whether or not to participate.
There are various types of genetic testing and during pregnancy, these diagnostic tests usually follow amniocentesis at around 16 week?s gestation. Chorionic villus sampling (CVS) can be carried out at around 10-12 week?s gestation although there are some additional risks, such as the increased risk of miscarriage, which needs to be balanced against the value of an earlier diagnosis. With the pre-implantation method, a limited amount of success has been reported with testing embryos for genetic disorders before implantation. It is technically possible to fertilise oocytes in vitro, remove one or two cells, and test them for a range of disorders. The early embryos continue to develop normally and those without the disorder maybe selected for replacement into the uterus for gestation. An even newer technique is in pre-conception diagnosis. Research is being undertaken into the removal of the polar body from the oocyte before fertilisation. It is suggested that an assessment of this material may eventually provide an effective method of determining the genetic constitution of the oocyte. Although research is continuing to develop methods of detecting genetic disorders at an earlier stage, the most feasible option for prenatal diagnosis now and for the foreseeable future, is testing during pregnancy (Russo and Cove 1995).
Amniocentesis and CVS can be used to diagnose the chromosomal sex/gender of the foetus. The phrase ?infertility treatment? has given way to ?assisted reproductive technology? (ART), the main emphasis of difference between these two phrases is that the former represents techniques for infertility and the danger of passing on genetic diseases only, whereas ART opens up new options to enable all people to ?engineer? their own reproductive lives, (Challoner, 1999).
An aspect of ART that is rapidly developing is sex/ gender selection, although in the United Kingdom choice is permitted only where a genetic disease is carried in a male line (Gosden, 1999). The desire, or in some cases pressure, to have a child of a particular sex/gender can be so great as to lead to late abortion or even infanticide. According to Gosden (1999) in humans, the ratio at birth is close to parity, about 105 boys for every 100 girls born. It was not until the turn of the last century, and the discovery of the sex chromosomes, that scientists came to understand how sex/gender is determined. The sex/gender of a baby is fixed according to whether a male or female sperm fertilises the egg. Half the sperm produced in each testis carry a Y chromosome, which is a short stretch of DNA carrying the genes needed to make the testes and produce sperm. The other half carries an X chromosome like the eggs. If sperm and egg meet by chance there should be an equal number of XY (male) and XX (female) embryos. The type of sperm therefore fixes the sex/gender of the embryo (BMA 1998).
There are various Assisted Reproductive Technologies in which to pre-select the sex/gender of a baby, pre-implantation genetic diagnosis provides a way to screen a selection of embryo?s produced by IVF, to analyse their genetic make-up. This can enable the transfer of only those embryos of a particular sex/gender, to help certain couples avoid passing on sex-linked genetic disorders (Challoner 1999).
There have been other more acceptable non-IVF methods of sex/gender selection, the most contemporary method was developed in 1998 and is named ?MicroSort? (sperm separation). It was developed by a geneticist called Edward Fugger at the Genetics and IVF Centre in Fairfax, USA. The high tech approach taken in MicroSort relies upon the fact that the X chromosome carries 2.8 per cent more DNA than the Y chromosome. Fluorescent molecules are made to attach to the DNA, and the sperms passed under ultraviolet light, which causes the molecules to emit light: the more light emitted the more DNA is present in a particular sperm. An automatic machine; a flow cytometer sorts large numbers of individual sperms quickly and with a high degree of accuracy (Fugger 1998).
Sex/Gender pre-selection has raised concerns among society and national groups of ethicists. For some people, a technology that could pick out the sex of a baby raises the issue of China?s overabundance of baby boys. Many Chinese couples opt for an abortion of a female foetus, and there has been speculation of the existence of ?dying rooms? in which female babies are left to die (Challoner 1999).
The preference for one sex is still very prevalent in large tracts of the world. In addition to China, India is said to be forty million women short of the numbers that a normal sex/gender ratio would assure. The abortion of female foetuses, infanticide and the early death of girls who are neglected or abandoned cause this deficit (Gosden 1999). Most people recoil at the thought of a society so geared towards male offspring that abortion, and infanticide, is the fate of some baby girls. However Caplan (1998) notes most couples in the West have only a moderate preference for a child of a given sex. The standing argument in the Western societies is that parents who have large families want a mixture of sons and daughters, and most patients attending sex/gender selection clinics already have children of the same sex/gender and seek another of the opposite. Once a male child has been born, parents are less concerned about the sex/gender of any later siblings. Statham et al (1993) conducted a survey of British women and was asked in the early stages of pregnancy if they minded what the sex/gender of their baby would be. Fifty eight percent said no and among those who expressed a strong preference six percent wanted a boy and an equal percentage wanted a girl. There was also only a hint of male bias in the minority sample of Afro-Caribbean and Asian women. Additionally over half of the women did not even want to know the sex/gender of their child before birth (Statham 1993).
Furthermore, Caplan (1998) says that only a small subset of Western populations would try to ensure their baby?s sex/gender with an expensive and difficult procedure. He notes that a man must first produce a sperm sample, then his partner must submit to artificial insemination. For couples, whose only concern is the gender of their baby, the rigmarole might very well put them off. Caplan (1998) argues that sex selection to balance a family is ethically acceptable but that it won?t be popular enough to change Mother Nature?s gender sorting.
Murray (1991) once noted that the trend towards more parental control over a child?s characteristics will increase in the future, and that scientists working on the Human Genome Project soon will have methods of identifying disease-causing genes as well as the DNA that produces characteristics such as hair colour, height, athletic ability, and perhaps even behaviour.
Most ethicists see no problem with parents trying to avoid a genetic disease in their offspring. Rothman (1998) does however argue that parents should leave the selection of non-disease traits to fate, although sex-selection techniques may be useful to limit the size of all-girl families where the parents might otherwise continue having babies until they get a son or of all-boy families intent on having a girl. Goldson (1999) notes that technology begins slowly and tentatively but becomes more efficient with time, and attitudes will probably change too. There will be a greater acceptance of family balancing, as it is always better to have a wanted child than an unwanted child.
Cloning is another area in which genetics can benefit reproductive needs. In particular it is helpful to a couple where the father is infertile and technically it could be possible to transfer the nucleus of a somatic cell from the father, into the egg cell of the mother (Appleyard 1999).
There are distinctions to be made between the types of cloning, the main difference here is ?cloning embryos? and ?cloning cells or cell lines? Single cells may be taken from embryos, foetuses, or even from adults and may be grown in culture. These can divide many times, each cell being the identical clone to the original. These cells are useful for study but cannot be grown into an embryo. Embryos grown in vitro may be divided into two or more separate embryos. Where this happens twins will result. This process has an in-built limit and so the prospect of infinitely reproducing identical embryos is not possible by cloning embryos (Harris 1998). Dawkins (1998) points out that therapeutically, the idea of cloning is important because, cloned individuals would share the same immune characteristics as each other. Possibilities arise in issues such as cloning an individual at the embryo stage so that one clone could be used as a cell tissue and organ bank for the other (Hamilton 1998).
The BMA (1998) point out that few issues linked to genetics has caused as much public outcry and fear as cloning. Especially after the news of the breakthrough with cloning sheep in Edinburgh and both national and international media heralded the inevitable and imminent use of the technique on humans. Most of the reports focused on the nightmare scenarios and the BMA (1998) suggest that this is unfortunate since the benefits that could arise from this research into cloning, have by contrast, been given little attention.
One other area of concern is the possible control and use of genetic information for social purposes, an area that can have a massive impact on family life. Due to the Human Genome Project, many human genes have already been cloned, making it possible in some cases to determine if a person has a defective gene that will make them sick later in life. Russo and Cove (1995) point out that genetic screening, based on the accumulated basic knowledge of many scientists, has two different aspects. On the one hand, molecular techniques can be used to screen couples who may both carry a defective gene For example, for cystic fibrosis sufferers, and to council them so they can decide whether or not they wish to have children. However, on the other hand, genetic screening can be used to discriminate against those who have a defective gene. For example, if they wish to obtain life, health, or other insurance. Employment issues can also have a huge impact on the whole family (Knoppers 1998).