Most rare diseases are genetic, and thus are present throughout the person's entire life, even if symptoms do not immediately appear. Many rare diseases appear early in life, and about 30 percent of children with rare diseases will die before reaching their fifth birthday. With a single diagnosed patient only, ribose-5-phosphate isomerase deficiency is considered the rarest genetic disease.
When the temperature in the core reaches about 100 million degrees, the helium will begin to fuse into carbon by a reaction known as the triple-alpha process, because it converts three helium nuclei into one carbon atom.This generates a great deal of heat.n heavier stars, the oxygen can in turn fuse with the helium to make neon.) Helium fusion produces only 9% as much energy per kilogram as hydrogen fusion, so energy-wise, the Sun continues to be mainly a hydrogen reactor. 90% of its luminosity still comes from burning hydrogen.
What happens to the Helium? Most stars, after converting a significant portion of their hydrogen to helium undergo an internal change. The internal core collapses, and heats up, until it is hot enough to fuse helium into larger atoms, for instance, by combining three helium atoms into carbon. At this same time, some helium will fuse with that carbon to produce oxygen. Outside the core, in what's called the envelope, there is still enough hydrogen to fuse into more helium. But the core begins fusing into larger atoms. This, by the way, is the transition from a 'normal' star like our Sun to a Red Giant. After the red giant phase the Sun will lose its outer layers leaving behind its helium-rich core, which will gradually cool over the lifetime of the Universe.