In recent years, much energy has been put into genetic research both through the individual efforts of interested scientists and through the collaboration of international teams in the Human Genome Project. Through this work, we have learned a great deal about how genes function and how they can cause certain problems. Genetic testing is possible for some conditions because we can recognize the difference between a normal gene and a disease gene. Genetic testing presents us with both opportunity and concern. There is opportunity for diagnoses and definitive information and, indeed, a hope that cures may ultimately be possible.
Genes are specific pieces of information that tell our bodies how to grow, function, and develop.
It is estimated that each person has between 50,000-100,000 genes. These genes, which are contained on our 23 pairs of chromosomes, make up our genetic blueprint. Each gene codes for a particular set of instructions, and a gene's function is determined by its unique DNA code. DNA consists of four basic building blocks called bases that are linked in a specific order. When a change occurs in the ordering or number of bases, a gene may not function properly.