Beginning of Essay
The word "" refers to a group of inherited conditions. People with have little or no pigment in their eyes, skin, or hair. They have inherited genes that do not make the usual amounts of a pigment called melanin. One person in 17,000 has some type of . affects p ....

Middle of Essay
.... "ty-positive". Persons with ty-negative albinism have no melanin pigmentation, and more difficulty with vision. Those with ty-positive albinism have very slight pigmentation, and generally less severe visual difficulties. Tests were done on the hair roots of individuals with albinism, to tell these types of albinism apart. However, these hair tests cannot identify types of albinism, particularly in young children, whose pigment systems are immature. Therefore hair tests are not helpful in predicting the extent of visual disability of a child. "Ty-Neg" (also called Type 1A) albinism results from a genetic defect in an enzyme called ty ....