Downs

            Down syndrome is a birth defect caused by a genetic disorder that affects 350,000 people in the United States. It is caused by abnormalities in the genes and is not inherited, meaning that parents do not pass this onto their children. In order to understand Down Syndrome, one must examine genetics of a "normal" person as well as a person with Down Syndrome.
             Genetics is the study of heredity, or how certain traits are passed from parents to their children. Genes are the basic unit of heredity while cells are the building blocks of your body. Each person has more than 100 trillion cells. Our genes are located in chromosomes. Each cell in your body contains 46 chromosomes or 23 pairs. In the case of a person with Down syndrome, there are 47 chromosomes. In 1956, a French researcher named Jerome Lejeune used a new powerful microscope to view human strands of DNA. DNA is what holds an individual person's genes. He studied these DNA strands and determined that there is an extra strand in chromosome 21, which is now called "Trisomy 21" tri meaning three and somy for the word chromosome - meaning three chromosomes. No one knows exactly what causes Down syndrome aside from it being genetic.
             Many years ago, this condition was known as "mongolism" or people that had it were called "mongolian idiots". But in later years, Asian people as well as parents of these children protested these terms and in the 1960's the condition became known as Down syndrome in honor of the English doctor John Langdon Down. Who, in 1866, studied people with mental retardation and noted distinct physical features in them. Some of the physical features associated with Down syndrome are low muscle tone, many newborns appear as floppy and not toned, they have flat facial features especially a small nose with a flattened nasal bridge. Their eyes are slightly slanted with small skin folds at the inner corner. The have a short neck, small abnormal shaped ears, and an enlarged tongue that often tends to protrude making speech difficult to understand.