Genetic Aspects of Diseases: Categories of Genetic Disorders

Abstract

Genetics is the study of heredity, the process by which various characters are transferred from parents to offspring so that human beings, and more generally all living organisms, resemble their ancestors. After the end of the Second World War and the discovery of antibiotics, with the sustained reduction in nutritional and infectious diseases (at least in developed countries) there has been an increasing awareness of the role of genetic factors in human diseases, including neoplasms. At variance with a common belief, genetic disorders are not rare; there are studies indicating that their contribution to total pediatric mortality is in the order of 30% –40% [1, 2], whereas in adults approximately 10% of all hospital admissions are due to genetic diseases. These, however, should be considered as minimum estimates, since the genetic nature of many diseases (in particular neoplasms) is becoming more and more apparent [3].

From the results of a series of straightforward though painstaking experiments, Mendel was able to deduce two fundamental Laws of Genetics. The rediscovery of Mendel’s work, and the acceptance of his results, led to the gene mapping techniques that still provide new information about gene structure and organization.T. A. Brown (1989)