Hyper IgE syndrome is rare with less than 850 cases reported worldwide. It affects both boys and girls equally. It is due to genetic mutation in the gene on chromosome 4. In some cases, the genetic mutation has not been identified.
Report Abuse. The tropical zone is characterised by strongly monsoonal weather patterns, distinct wet and dry periods which are highly reliable, large quantities of rain and high intensity rainfall, high temperatures, and high rates of energy transformation.
While those parts of the tropics such as coastal West Africa, west-central Africa, and southern India get abundant rainfall, there is also an arid zone extending across northern Africa (the Sahara) and northwest India, and another arid zone in southwestern Africa.. The tropical zone falls between the Tropic of Cancer in the north and the Tropic of Capricorn in the south. The Afro-Asian tropics have a cycle of rainy and dry seasons dictated by the alternating winds known as monsoons.