SLHS 1150 Lecture Notes - Lecture 23: Down Syndrome, Intellectual Disability, Bone
Document Summary
Down syndrome is a genetic condition that occurs in 1 of every 700 live births. It affects people of all ages, races and economic levels and is the most frequently occurring chromosomal abnormality. More than 400,000 people have down syndrome in the united states. The most common form of down syndrome, trisomy 21, occurs when there are three instead of two number 21 chromosomes in every cell of the body. Instead of 46 chromosomes, a person with trisomy 21 has 47. This extra genetic material alters the course of development and causes the characteristics associated with down syndrome. Is it downs, down"s, or down? capital s in syndrome. There is no apostrophe and there is no. The syndrome is named after the physician, dr. john langdon down, who identified the common characteristics as a syndrome in 1866. A child with this condition is a child with down syndrome, not a down"s child of the.