HeMe #5 - Page 15

What is Down’s Syndrome ? Down syndrome is a chromosomal disorder which is caused by a delusion in cell division that results in full or partial extra copy of chromosome 21.The additional genetic material changes the course of development. This results in having the signs of Down syndrome. This condition leads to impairments in both cognitive ability and physical growth. When Was Down Syndrome Discovered? John Langdon Down, an English physician, published a description of a person with Down syndrome in 1866. Before Down, some people had recognized the signs of the syndrome. But Down was the one who explained the condition as a separate entity. What are the causes of Down’s syndrome ? The cause of the disease is unknown. There is no any research that signifies Down syndrome is caused by environmental factors ( external ) or the parents' activities before or during pregnancy. Some researchers have shown that this condition increases as a woman ages. The additional genetic structure of the 21st chromosome which causes Down syndrome can flow from either the father or the mother. Most often it is flown from the mother. Research has shown that 5% of the cases have been originated from the father. What are the physical signs of Down’s syndrome ? >Decreased muscle tone at birth >Excess skin at the nape of the neck > Flattened nose > Separated joints between the bones of the skull (sutures) > Small ears > Small mouth > Upward slanting eyes