The pressure decreases because there is less density meaning there are less atoms or molecules in a space. Gravity determines the density by pulling in more molecules towards â¦ the center of the Earth.
Therefore, about 85-90 percent of children with hereditary retinoblastoma develop multiple tumors that affect both eyes (bilateral disease). The remaining 10-15 percent of patients with hereditary retinoblastoma develop only a single eye tumor (unilateral disease).
The alpha and beta thalassaemias are the most common inherited single-gene disorders in the world with the highest prevalence in areas where malaria was or still is endemic. The burden of this disorder in many regions is of such a magnitude that it represents a major public health concern. For example in Iran, it is estimated that about 8,000 pregnancies are at risk each year.