Genetics Overview

How do Markers Help Find Genes that Cause Disorders?

Scientists test many different markers on all the chromosomes, trying to find markers that are consistently found in people who have a particular disorder more frequently than those without the disorder. These markers are landmarks that identify which chromosome a disorder gene is located on (like which country your friend’s house is in). Certain statistical methods can tell a scientist how close these landmarks are to a gene. Testing more markers will narrow the search area of the gene (like which city a friend’s house is in).