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.
Braille is named after its creator, Frenchman Louis Braille, who lost his eyesight due to a childhood accident. In 1824, at the age of 15, Braille developed his code for the French alphabet as an improvement on night writing. He published his system, which subsequently included musical notation, in 1829. The second revision, published in 1837, was the first binary form of writing developed in the modern era.