Teratology
It is a sub-discipline in medical genetics which focuses on the classification of congenital abnormalities in dysmorphology caused by teratogens and also in pharmacology and toxicology.
[3] The related term developmental toxicity includes all manifestations of abnormal development that are caused by environmental insult.
[6] The term was borrowed in 1842 from the French tératologie, where it was formed in 1830 from the Greek τέρας teras (word stem τέρατ- terat-), meaning "sign sent by the gods, portent, marvel, monster", and -ologie (-ology), used to designate a discourse, treaty, science, theory, or study of some topic.
In the 1960s, David W. Smith of the University of Washington Medical School (one of the researchers who became known in 1973 for the discovery of fetal alcohol syndrome),[8] popularized the term teratology.
[9] In 1959 and in his 1973 monograph Environment and Birth Defects, embryologist James Wilson put forth six principles of teratogenesis to guide the study and understanding of teratogenic agents and their effects on developing organisms.
[10] These principles were derived from and expanded on by those laid forth by zoologist Camille Dareste in the late 1800s:[10][11] Common causes of teratogenesis include:[12][13] In humans, congenital disorders resulted in about 510,000 deaths globally in 2010.
[29][30][31] Etretinate (trade name Tegison) is a medication developed by Hoffmann–La Roche that was approved by the FDA in 1986 to treat severe psoriasis.
This can cause a multitude of congenital abnormalities and deformities, many of which can ultimately affect the fetus and even the mother's reproductive system in the long term.
[39][40][41] When hormones such as estrogen and testosterone are replaced, this can cause the fetus to become stunted in growth, born prematurely with a lower birth weight, develop mental retardation, while in turn causing the mother's ovarian reserve to be depleted while increasing ovarian follicular recruitment.
[42] Thalidomide was once prescribed therapeutically from the 1950s to early 1960s in Europe as an anti-nausea medication to alleviate morning sickness among pregnant women.
[citation needed] There are a wide range of affects that Prenatal Alcohol Exposure (PAE) can have on a developing fetus.
Some of the most prominent possible outcomes include the development of Fetal Alcohol Syndrome, a reduction in brain volume, still births, spontaneous abortions, impairments of the nervous system, and much more.
[47] Consuming tobacco products while pregnant or breastfeeding can have significant negative impacts on the health and development of the unborn child and newborn infant.
The Greek physician Pedanius Dioscorides described the effects of lead exposure as something that "makes the mind give way."
[50] Specifically, fetal exposure to lead can cause cognitive impairment, premature births, unplanned abortions, ADHD, and much more.
[53] Evidence for congenital deformities found in the fossil record is studied by paleopathologists, specialists in ancient disease and injury.
Fossils bearing evidence of congenital deformity are scientifically significant because they can help scientists infer the evolutionary history of life's developmental processes.
Other notable fossil deformities include a hatchling specimen of the bird-like dinosaur, Troodon, the tip of whose jaw was twisted.
[56] It has been observed in chick embryos that exposure to thalidomide can induce limb outgrowth deformities, due to increased oxidative stress interfering with the Wnt signaling pathway, increasing apoptosis, and damaging immature blood vessels in developing limb buds.
Many detrimental effects, and signs of teratogenesis were found, such as negative impacts on the formation of the cerebellum, fetal mortality, and developmental issues for various parts of the body.
[61] Plants can have mutations that leads to different types of deformations such as:[citation needed] Studies designed to test the teratogenic potential of environmental agents use animal model systems (e.g., rat, mouse, rabbit, dog, and monkey).
Early teratologists exposed pregnant animals to environmental agents and observed the fetuses for gross visceral and skeletal abnormalities.
[66] Understanding how a teratogen causes its effect is not only important in preventing congenital abnormalities but also has the potential for developing new therapeutic drugs safe for use with pregnant women.
