Scientists learn to identify genetic markers for specific diseases by comparing the genetic structure of people who the disorder with people who do not. Today, consumers can order genetic testing to discover whether they are at increased risk of certain diseases. Companies like those founded by entrepreneur Jim Plante focus on genetics for improved health and disease prevention.
A gene is a segment of DNA. DNA is organized into structures known as chromosomes. Chromosomes are found in every cell of the body. A normal structure would include 23 pairs of chromosomes in each cell. The average human body contains around 37 trillion cells.
The number of human genes is still unclear, as scientists have been reducing their estimates over the years. It looks as though 20,000 to 24,000 genes are contained in a human body.
Genetic disorders are caused partly or entirely by an abnormality in the person’s DNA that can be identified through testing by a company such as Pathway Genomics. This might be a gene mutation or more than one mutation, or chromosome damage. There may be an additional chromosome or a missing one, or damage to the structure. Environmental factors and actions by the people can be a factor too. For example, some birth defects are caused by a pregnant woman taking a certain drug. A person may be born with a genetic mutation or may develop one later.
Reasons for Testing
People may want this information simply for their own knowledge, to learn whether they should start taking preventive measures, or to make plans in the event that the disease does develop. There are almost innumerable reasons why men and women decide to have genetic testing done.
Sometimes the testing is controversial to a certain extent, such as a pregnant woman wanting to have screening performed to test the fetus for Down syndrome, a chromosomal abnormality. Some individuals worry that news confirming this possibility will lead to the woman deciding to have an abortion. However, this woman may plan to have the baby and wants to be able to thoroughly prepare for a disabled child’s arrival.