1、 Slide 16a:Genes are made up of DNA which is packaged on 46 chromosomes in the cell nucleus. The DNA of the human genome is estimated to contain some three billion nucleotide base pairs, made up of combinations of the four bases: adenine, cytosine, thymine and guanine. Amongst these there are over 3
2、 million (one in every thousand) single base pair changes which differ among individuals. This is known as a single nucleotide polymorphism or SNP. One of the best examples of diagnosing disease more effectively involves the most common form of childhood leukemiaacute lymphoblastic leukemia.Genetic tests are able to determine the exact chromosomal structure of the individual childs disease. That allows physicians to select the optimal drug and dosage for each child. You can see some of the results: In 1962, about 4 percent of children were cured. Now that is over 80 percent.
