Before advances in genetic applications, gene therapy was unheard of and genetic defects were always inherited, plaguing generations. Today genetic testing is widely available, such as prenatal karyotyping of chromosomes to check for genetic abnormalities. Genetic testing is also useful for families in which autosomal recessive disorders are known to exist, when these are planning to have children. In addition, genetic testing is available for people who might have inherited a genetic disorder which only becomes apparent later in life (for example Huntington's Disease). Individual choice decides whether a person would rather know if they are particularly vulnerable to certain diseases or more likely to die young. Knowing that your life may be short could inspire you to make the most of it while it could equally well cause severe depression.
Today`s advances in gene therapy make it possible to even remove a faulty gene and replace it with a functioning gene in cells lacking this function. Though these techniques are available, they are still in the experimental stages. Somatic cell therapy, for example, uses faulty genes to target the affected areas for genetic treatment. This technique is beneficial in the treatment of cancers and lung, blood and liver disorders. Since the treatment is localised, any unwanted effects of this are not passed on to the next generation.
A more controversial technique is the genetic alteration of gametes which causes a permanent change for the organism as well as for subsequent generations. Of course if the gene is corrected without further negative effects, the genetic disorder has been
successfully eliminated; but if a problem arises it could pass on.
These advances in genetic engineering make the possibility of "designer babies" a reality. When the choice to change every aspect of every characteristic of a child is available, who would refuse? Why have an average child, when it is possible to have one with perfect health, good looking, intelligent and matching every other desirable characteristic which parents could want? The benefits seem endless: the potential for a perfect society without physical imperfections, low intelligence nor undesirable personality traits. How far this could go, is unpredictable; theoretically humans could for example be made more efficient - requiring less food but able to work harder.
However, one of the problems with changing the structure of human DNA, is the subsequent loss of natural variation. As well as the unattractive possibility of very little variation in personalities and looks, the loss of natural variation would stop the formation of new genes, thereby severely decreasing the available gene pool. On the larger scale of life, natural variation is vital for subtle adaptions that help species accommodate to changing environments. If genetic alterations become widespread, genes required for particular circumstances or different environments that may be encountered by the organism, could conceivably be bred out. If then the organism encounters a change without the gene which would have made adaptation possible, it could suffer or even perish.
Another large problem with all types of genetic engineering is the interdependence of genes: while on the one hand one gene may code for several features, on the other hand many genes are frequently required to code for one characteristic. While chromosome mapping is useful, without test crossing with every possible variable characteristic of an organism, it cannot be known what the functions of each gene are. Hence when a gene is removed, what is known about the function of that gene may not be all it codes for. The removed gene may also have a...