“cellular DNA may be fragmented, tagged with a fluorescent marker, and checked for its binding pattern with microarrays of DNA sequences on glass chips. In addition, the genetic abnormalities associated with various leukemias and lymphomas can be rapidly detected with the aid of the so- called B/T gene rearrangement test. The test is based on the recognition that most leukemias and lymphomas are characterized by genetic rearrangements in the B and T cells of the bloodstream. A study conducted at the University of Ulm in Germany revealed a correlation between various chromosomal abnormalities and the length of survival of leukemia patients. Analysis of the rearrangements has permitted patients to benefit from more expeditious and accurate diagnoses that, in turn, have led to more appropriate treatments” (Bhandari et. al., 1999).
The technology to pre-determining the gender of a developing fetus is a recent development in medical science. The two most prevalent techniques used are sperm sorting and genetic testing. The techniques work on the principle that a random sample of sperm will contain an equal mix of male and female chromosomes, “although girl-making sperm are heavier and slower, due to carrying more DNA, than their male counterparts” (Bhandari et. al., 1999). Nevertheless, they can be separated and marked with a fluorescent marker in the flow cytometer machine. Presently, this molecular genetic technique is only offered in the United States. The other technique employs a centrifuge to segregate X and Y chromosomes. After this, the sperm can be used for In-Vitro-Fertilization or intrauterine insemination procedures. The government is yet to draft comprehensive regulations to monitor their use. Moreover, the success rates so far have not been outstanding. A technique that has found greater success is called pre-implantation genetic diagnostics (PGD) (Silverman, 2005). After an egg is fertilized through IVF or Intracytoplasmic Sperm Injection (ICSI), a cell is sampled from the embryo to test for diseases as well as to determine the sex of the developing embryo. Conditions such as cystic fibrosis, Huntington’s disease, Haemophilia and Down’s syndrome could all be detected at this early stage, so that the parents can choose between continuing the pregnancy and aborting it. Although this technology was intended to prevent the birth of defective children, it has been used by some clinics as a sex-selection offer, which raises many unaddressed questions of ethics and morality (Silverman, 2005).
In the United States, due to the improvements in genetic diagnostic devices and the assurance from the Food and Drug Administration, doctors are starting to gain insights into how certain diseases pass from one generation to the next. The Tag-It Cystic Fibrosis Kit is one such device. Cleared for marketing in May 2005, “Tag-It finds genetic variations in what scientists now know is the gene that causes cystic fibrosis–the most common fatal genetic disease in the United States. Made by Tm Bioscience Corp. of Toronto, Tag-It will help diagnose cystic fibrosis in children and identify adults who are carriers of the gene” (Silverstein, 2001).
Moreover, with the human genome project having been completed, it provides physicians with a comprehensive source of information about the “structure, organization, and function of the entire set of human genes–all 30,000 to 40,000 of them–and an idea which ones affect health and disease” (Silverstein, 2001). This genetic database, alongside another research tool called a microarray, gives a brief overview of genes that are active in both normal and diseased cells. A microarray, also referred to as a gene chip,
“is a tiny glass or plastic platform containing thousands of genes. It is similar to a computer microchip, but instead of tiny circuits, the chip contains “probes” or genes with a known identity, such as DNA or small pieces of DNA, which are arranged in a grid pattern on the chip. Whenever genetic material from a patient’s blood or other tissue is placed on the chip, the probes react. Those reactions can be detected and used to screen for the presence of particular genetic sequences, such as those related to diseases, and how people will respond to certain medications. Microarrays also can enable researchers to see which genes are being switched on and off under different medical conditions” (Breheny, 2007).