Essay: Abnormal development in embryos with Down syndrome
In the field of teratology and its many studies in the structural abnormalities which arise during embryonic development, congenital abnormalities are common. Teratology is moving to more molecular analysis of the development abnormalities in the today’s contemporary medical world that is engulfed by dynamics and ever changes in molecular characteristics. The major causes of abnormal development as revealed in the teratology studies are: malformations which are abnormalities development resulting from errors in genetic programming like mutation in genes, aneuploidies and structural changes in chromosomes. And second major identified sources to cause abnormal development in embryo are factors from unknown causes that interfere with development of an embryo or the environmental agents.
As Michelson (2000) puts it, there are no sensitive periods of teratogens, but depends on when and the dose when an embryo encounters the teratogens. However, he further cautions that human organs are sensitive between the periods of day 15 to day 60 of gestation, whereby and dosage encounter by the embryo during this period might result to abnormal development of the fetus. Despite lack of clarity to the sensitive periods of teratogens, teratogen agents have been successfully identified since exposure of developing fetus to teratogens definitely leads to congenital abnormalities.
Teratogen agents are: Metabolic conditions in the mother like Auto immune disease, Phenylketonuria and Diabetes. Secondly, Natural Teratogens like Ionizing radiations and some poisonous plants like Skunk cabbage veratrum. Thirdly, Industrial Teratogens like Lead, Arsenic and Cadmium. Fourthly, Recreational Teratogens like Heroin, Cocaine and Alcohol. Fifth, Microbial Teratogens like toxoplasmosis Herpes simplex and syphilis. And lastly, Pharmaceutical Teratogens like Thalidoamide, Retionic acid, and Penicillin Tetracycline. Therefore, this paper shall examine congenital abnormalities (chromosomal abnormalities) resulting from genetic errors in patients with Down syndrome.