2003
Many men, women, and children of today's world suffers from a birth defect called Down's Syndrome. While the cause it not yet known, scientists have pin pointed the problem. While an average healthy human has a normal set of chromosomes (shown in the picture below.)
A person with Down's Syndrome as three chromosomes of the chromosome 21. Seen here:
Researchers are busy in their attempts to map out the full structure of the chromosome, including the Human Genome Database. Because of the small size of the 21st chromosome and its association with Down Syndrome, it is the second-most heavily mapped human chromosome. Research is focusing on trying to identify genes and their effects when overexpressed.
However, many feel it would be a mistake to assume that the clinical features of Down Syndrome are only due to a handful of genes being overexpressed. You can think of the overexpressed gene products interacting with a number of normal gene products, each product individualized by the person's unique genetic makeup, and thus being thrown "out of genetic balance." This would then make the person more susceptible to other genetic and environmental insults, leading to the features, diseases and conditions associated with Down syndrome. It is this complex arrangement that scientists will be addressing in the second century of Down syndrome research.