what is a genetic marker

A genetic marker is a DNA sequence with a known location on a chromosome that helps scientists track inherited traits, disease risk, or nearby genes. It can be a gene itself or a nearby DNA variation that acts like a signpost.

Quick Scoop

Genetic markers are useful because DNA segments close together on a chromosome tend to be inherited together. That makes markers valuable for mapping genes, studying family inheritance, identifying individuals or species, and researching inherited diseases.

Simple example

If researchers know a marker is always near a disease-causing gene, they can use that marker to help locate the gene even before the exact mutation is found. This is why genetic markers are common in genetics research, medicine, and forensic identification.

Main point

In plain language, a genetic marker is a recognizable DNA “landmark” that tells scientists where they are in the genome and what nearby genetic information may matter.