Monday, June 6, 2011

Genetic Testing And Screening Ethical Issues

Genetics, a discipline of biology is the science of heredity and variation in living organisms. The fact that living things inherit traits from their parents has been used since prehistoric times to improve crops and animals through selective breeding. However, the modern science of genetics, which seeks to understand the process of inheritance, only began with the work of Gregor Mendel in the mid-nineteenth century.

Genetic testing is one of the important techniques of medical science to detect alterations in genes and chromosomes of an individual. It helps in the diagnosis of genetic diseases, risk prediction of occurrence of the disease and also to identify carriers of genetic disorders.

Genetic testing or screening ethical issues is a procedure to determine changes in the genes, proteins and chromosomes. There are about 20,000 - 25,000 genes in the human genome. Genetic tests are performed to diagnose abnormalities in the content of the genome of an individual who is responsible for causing genetic disorders. Besides the study of genes and chromosomes, genetic testing involving biochemical tests to identify proteins that indicate the anomalous genes.

In genetic testing, the genes of an individual from cells (blood or other bodily fluid samples) were examined for any changes. The possible results are: there can be no removal or addition of bases in the DNA chain. Sometimes a piece of a chromosome or an entire chromosome may be added, deleted or moved. In such situations, the genes can be suppressed or expressed again. An individual can lead to abnormal genes without expressing them or can express genes that lead to genetic disease.

Let's look at the details of some of the common genetic tests,

Prenatal genetic testing:

As the name suggests, prenatal genetic tests are performed to identify genetic disorders in the fetus during pregnancy. Genetic disorders such as Down syndrome, neural tube defects and other chromosomal abnormalities can be detected with this test before birth. If a positive result for either disorder, parents can opt for abortion. Can also be used to determine the sex of the fetus. However, it is illegal, if the abortion is performed after determining the sex of the fetus.

Preimplantation Genetic Diagnosis (PGD):

preimplantation genetic diagnosis or screening the embryo is an alternative to prenatal testing. Here, genetic testing is performed on embryos before implantation and, sometimes, in the oocytes before fertilization. Generally, an embryo from in vitro fertilization (IVF) is tested before implanting in the uterus. DGP aid in the identification of embryos, which represent a risk for certain genetic disorders. Many couples opt for PGD in place of prenatal diagnosis, to diagnose genetic disorders in advance to avoid the dilemma of abortion.

Newborn genetic screening:

Newborn screening is done to identify genetic genetic disorders in newborns. In this procedure, the baby's DNA sample is studied for defects. Studies were also conducted to confirm the absence of key proteins that are essential for the proper functioning of the body. The early diagnosis of any genetic disorder will be useful in reducing the symptoms that can lead to disability and other chronic diseases.

Predictive Genetic Testing:

predictive testing is done to look for problems that have been inherited from the family. In many cases of genetic disorders, family members with the same disease. In other words, the defective gene in the family. In predictive genetic tests, DNA samples of family members studied to make any common genetic disorder. In general, a comparison between the content of the genome of an individual suffering from the disease and a person who is free of the disease. Thus, the defective gene is marked for further processing and study. It has been found that when a family history of cancer, cancer-causing genes are present among the majority members of the family.

No comments:

Post a Comment