Unfortunately, many disorders and diseases are caused due to the abnormalities of the genes or chromosomes. Many diseases tend to run in family because they are inheritable due to the certain genes.
In order to discover the possible alternations in genes and chromosomes, the genetic testing is necessary. It is one of the essential techniques in the medical science, which helps in establishing genetic disorders. Furthermore, a genetic test can predict the risk factors of a disease's appearance. The carries of genetic disorders can also be identified by the genetic testing. It is estimated that there are about 20000 to 25000 genes in a human genome and only one abnormal gene is enough to cause certain disorder or disease.
Genetic testing includes the study of genes, chromosomes, and biochemical tests that identify the proteins that indicate anomalous genes. When a genetic test is performed, the genes from cells are studied in order to find any alternation. When certain alterations occur, they may be either deletion or addition of bases in the DNA strand. As a consequence of that, the genes appear suppressed or over expressed.
Different genetic tests
Genetics is a very advanced branch of medicine and due to that, there are even about 900 genetic tests.
- Prenatal genetic tests are done in order to discover certain genetic disorders in a fetus when a woman is pregnant. The most common genetic disorders that can be detected before the birth with this kind of test are Down syndrome, neural tube defects, and many other chromosomal abnormalities. The sex of the fetus can also be determined with this test.
- Preimplantation genetic diagnosis serves as an alternative test to prenatal genetic test. With this test, the embryo before the implantation and oocytes before fertilization are tested. Since this test is done before the implantation of the embryo in the uterus, many parents usually decide to do this test instead of prenatal test.
- Newborn genetic screening is a type of test used to discover certain genetic disorders in newborn babies. DNA sample of the baby is studied. With this test, the deficiency of the essential proteins may be detected.
- Predictive tests are a kind of genetic tests that are used in order to discover the diseases that are inheritable and that tend to run in family. In this type of the genetic tests, DNA samples of the family members are taken and studied and then compared in order to discover some common genetic disorder.