The ABO system consists of A, B, AB, and O blood types. People with type A have antibodies in the blood against type B. People with type B have antibodies in the blood against type A. People with AB have no anti-A or anti-B antibodies.
Developmental dyslexia, or specific reading disability, is a disorder in which children with normal intelligence and sensory abilities show learning deficits for reading.
Among children in U.S. public schools, three in 20 receive special education for reading problems; 3 to 5 percent of those kids most likely have dyslexia. Boys are diagnosed with dyslexia more often than girls, though some research indicates that this may be at least partially due to bias on the part of some medical professionals. Some experts believe that dyslexia is the most common learning disability, affecting 5 percent or more of all elementary age children. What causes dyslexia?