I. Introduction. 1  The petroleum industry began with the successful drilling of the first commercial oil well in 1859, and the opening of the first refinery two years later to process the crude into kerosene.
The cause of Down syndrome is one of three types of abnormal cell division involving chromosome 21. All three abnormalities result in extra genetic material from chromosome 21, which is responsible for the characteristic features and developmental problems of Down syndrome.
Scientists have successfully turned off the chromosome defect that causes Down syndrome. Down syndrome, also called Trisomy 21, is a genetic condition in which a person has three copies of chromosome 21, resulting in 47 chromosomes instead of 46. It is one of the most common causes of human birth defects. According to the Centers for Disease Control and Prevention, Down syndrome had an incidence rate of 11.8 babies per 10,000 live births from 1999 to 2003.