The family history or pedigree method is a method used by some experts in order to shed some light into possible clues and explanation regarding the present outcome of an individual. According to the Genetic Alliance (2009) family history holds an important link about the person’s past and future life and family history can be used as a diagnostic tool in the health profession. Medical professionals have noted that both common and rare diseases can run in the family (Bennet, 1991). The method can be performed in several methods using charts, forms, checklists, forms and pedigrees. The concept of a pedigree is collecting family history and allows the distinction of patterns in the genetic predisposition of individuals. The main limitation of the family history or pedigree method is that it can not distinguish or separate whether the disease or situation is a product of genetics or environment. The main reason is that families tend to live together, therefore, are exposed to same environment, making it hard to distinguish if genetics or environment played a more significant role.
The Twin Method
The classic Twin Method uses genetically identical twins to determine and investigate the effects of genetics and environmental factors on the development of individual traits. The method can use the comparison between the identical twins that are brought up in two different environmental contexts. The procedure hypothesized that the difference between the twins is the result of the environmental factor. Another method under the twin study involves subjecting one of the twins to test while the other is put into control (Kent, 2007). The more classical method of this approach is using the comparison between monozygotic (identical) and dizygotic (fraternal) twins. Through the use of the approach research formulated the probable effect of genetic inheritance and environmental factors (shared and unique) in understanding trait formulation. The main limitation of the method is that it does not hold a universal truth about it, due to the results of the twin studies can not be used to generalize beyond the samples used in the researchers.
References:
Bennett RL. The Practical Guide to the Genetic Family History. New York: Wiley-Liss, Inc. Centers for Disease Control and Prevention. Office of Genomics and Disease Prevention. Using Family History to Promote Health. 1991 www.cdc.gov/genomics/public/famhist.htm.
Genetic Alliance; The New York-Mid-Atlantic Consortium for Genetic and Newborn Screening Services. Washington (DC): Genetic Alliance; 2009 Jul 8.
Kent M. Oxford Dictionary of Sports Science & Medicine The Oxford Dictionary of Sports Science & Medicine. 2007
