This means that Hairy cell leukemia, or a subtype of Hairy cell leukemia, affects less than 200,000 people in the US population. Ophanet, a consortium of European partners, currently defines a condition rare when it affects 1 person per 2,000. They list Hairy cell leukemia as a rare disease.
In fact, some of the oldest alphabetic symbols have been found in Central America (2,500 years ago), China (more than 3,000 years ago), and the Middle East (more than 5,000 years ago). One of the earliest forms of the alphabet was hieroglyphics. Hieroglyphics were single symbols that stood for entire words.
The earliest writing systems evolved independently and at roughly the same time in Egypt and Mesopotamia, but current scholarship suggests that Mesopotamiaâs writing appeared first. That writing system, invented by the Sumerians, emerged in Mesopotamia around 3500 BCE. At first, this writing was representational: a bull might be represented by a picture of a bull, and a pictograph of barley signified the word barley.