Teratology: Causes, Principles, and Prenatal Diagnosis

Introduction to Teratology

Teratology is the study of physical abnormalities. Such abnormalities occur naturally through physiological means, although the environment and environmental factors — which can impact an organism's biology and physiology — play a part in this study as well. Typically, teratology is concerned with physical deformities in organisms. Initially, such deformities pertained to people, although this discipline has evolved to include virtually any sort of living organism. Moreover, teratology is concerned with the manifestation and development of physical abnormalities throughout the various stages of life.

Typically, these deformities begin during the process that occurs immediately after conception, when organisms are developing. However, they can also extend through periods of puberty and can encompass virtually any stage of life prior to death. It is critical to note that when discussing the natural origin of the deformities that are a part of this science, the environment can play a considerable role in the creation of these abnormalities. For instance, waste, toxicities, and radiation can drastically alter an organism's environment, causing creatures within that environment to procreate with a number of differences distinct from those procreating in a different environment. Teratology is concerned with all of these different aspects of deformities.

The Six Core Principles of Teratology

Although there are a variety of different principles associated with teratology, there are six fundamental ones that operate at the core of this discipline. The most important of these principles is the tenet that the likelihood of abnormality depends on the type of conception and the way in which that conception interacts with the environment (Aston, 2014). The second principle relates to the developmental stage of an organism being conceived and its relationship to any transformative agents within the environment — some points in the developmental stage are simply more vulnerable to agents than others.

The third principle is that agents of teratology produce specific effects on developing organisms and on certain tissues in order to initiate the physical abnormality process. The fourth principle is that a number of different factors associated with the exposure of an organism to teratogenic agents account for the degree of deformation. These include the point of contact between the two, the nature of that contact, and the length of time of exposure. Once an agent has interacted with an organism such that deformation occurs, there are only four possible outcomes: the end of life, physical deformity, retarded growth, or functional problems (Aston, 2014). Lastly, the greater the influence — in degree, quantity, and frequency of occurrence — of agents that produce physical deformity, the more likely and severe the manifestations of abnormality will become.

Hereditary Causes of Congenital Malformations

There are several hereditary causes for congenital malformations associated with teratology. The first is simple genetics. If a mother or father has some sort of congenital deformity, there is a greater likelihood that his or her offspring will have a similar, or perhaps different, deformity. The same concept applies to having a family history of congenital deformity — it leaves offspring produced by members of that family more susceptible to such conditions.

Another prominent cause of congenital malformations based on heredity is attributed to genetic diseases. There are a number of different genetic diseases that can result in such deformity, including those pertaining to defects in single genes, multiple genes, and chromosomes. As with most genetic factors, some traits — and the likelihood for their physical manifestation — are dominant, whereas others are recessive. Chromosomal abnormalities carry a significant likelihood of manifesting in some form of physical abnormality.

References

Aston, S. (2014). James G. Wilson's six principles of teratology. The Embryo Project Encyclopedia.

Marino, T., & Ramus, R. M. (2015). Prenatal diagnosis for congenital malformations and genetic disorders. Medscape.

Morris, R. S. (2015). Embryoscopy: a superior method for the evaluation of miscarriage. www.ivf1.com.

Chung, W. (2015). Teratogens and their effects. www.columbia.edu.