Genetics Overview

How do Scientists Search for Genes?

Looking for a gene is a difficult task and often takes years to accomplish. Scientists use maps of the chromosomes (similar to a road map) to look for genes. Searching for genes that cause a specific disorder is somewhat like trying to find a street on a map of the world. Using certain landmarks the location can be narrowed down.

Just as gas stations, restaurants, and sites like the Eifel tower can be used as landmarks when locating a friend’s house, scientists use markers to find a gene. Markers are areas of DNA along the chromosomes where the letters A, T, G, and C differ from one individual to the next. These differences (called polymorphisms) do not usually affect a person’s health. They act as flags that can be tested in individuals.

Scientists have maps of the markers on each chromosome, just like people have maps that tell them where streets are. The Genome Project developed a detailed map of the entire human genome. It provides researchers with lots of markers to test when looking for genes that contribute to disorders.

Analyzing these markers in research has just got a lot easier thanks to improvements in technology. We can find and record these markers in research subjects faster than ever before. What used to take months or years can now be done in days or weeks. This should speed the process for finding genetic differences that contribute to disorders.