An Overview of Molecular Genetics

  • Gregory J. Tsongalis
Part of the Pathology and Laboratory Medicine book series (PLM)


Sir Archibald Garrod concluded in the early 1900s that predisposition to disease is dependent on each individual’s chemical composition (1). Beadle later described the one gene—one enzyme concept, which emphasized the genetic control of biochemical processes and theorized that mutations in any given gene would result in a defective biochemical reaction (2). In 1953, Watson and Crick described for the first time the structure of the DNA molecule, which is now recognized as the “blueprint” of all living things (3). As part of their report, they described in detail the nature of complementary base pairing as part of the stoichiometry necessary for this structure to maintain its integrity. The current concepts of molecular mechanisms of disease have evolved from these early observations. Our ability to detect various alterations, both intra- and extrachromosomal, at the molecular level has led to a revolution in laboratory medicine giving way to our understanding of molecular mechanisms of disease processes or molecular pathology. The fact that these alterations play significant roles in disease inheritance and that many human diseases can now be associated with defects at the gene level has expanded our knowledge of the mechanism of inheritance based on the acquisition of half of our genetic makeup from each parent. Thus, molecular genetics provides an avenue for examining inheritance patterns at the level of nucleic acids and provides a vehicle for dissecting complex pathophysiological processes into gene defects.


Inheritance Pattern Myotonic Dystrophy Normal Allele Uniparental Disomy Family Pedigree 
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Copyright information

© Springer Science+Business Media New York 1997

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  • Gregory J. Tsongalis

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