The Etiology and Prediction in Segregated Populations

**39**

**Chapter 3**

**Abstract**

**1. Introduction**

Preeclampsia

*Sarah I.Y. Ahmed*

Placental Adaptation to Hypoxia

The ability of the placenta to interact with surrounding microenvironment of hypoxia can serve as a predictive marker for the development of preeclampsia. Lessons can be studied from highlands inhabitants and their ability to survive extreme conditions of hypobaric hypoxia. Many candidate genes loci that are associated with adaptation to high altitude hypoxia and healthy exercise are also associated with adaptation to hypoxia in normal pregnancy. This can pave the way to a new approach based on the concept of evolution and adaptation stating that "genes can undergo a process of natural selection for the fittest adaptive variants, so as to reach a state of adaptation to the scarce microenvironments." Accordingly, the degree of adaptation in candidate genes and their polymorphisms can serve as predictive markers for the development of preeclampsia. This can be seen in the high degree of concordance between gene expression and the lesions seen in the placenta and other remote organs in the different subtypes of preeclampsia. To conclude, "adaptive or less adaptive" can be the genetic result that answers the question of

Throughout the lives of individuals, their genes interact with their environments to cause variations in phenotype traits. Because individuals with certain traits tend to survive and reproduce more than others with less successful traits, the population evolves. In 1859, Charles Darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. He defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved" [1]. Although the Darwinian theory was ages before the genome era, it can also explain the process of natural selection at molecular levels; cells with successful traits are best adapted to their microenvironments, and more likely to survive and proliferate. The selection between cells favors those with the most advantageous genetic polymorphisms. The genetic variability is usually enhanced by the scarce microenvironments like low oxygen, low temperature, and high radiation that act as competitive milieus for cells. The useful genetic variants are preserved and can be heritable. Some 2.4 billion years ago, photosynthesis leads to the accumulation of oxygen

to levels that were likely toxic to many microorganisms. Organisms that could

as a Predictive Marker for

disease prediction, recurrence, and possible complications.

**Keywords:** placenta, adaptation, hypoxia, predictive marker
