genetic marker

(jeh-NEH-tik MAR-ker)
Alteration in DNA that may indicate an increased risk of developing a specific disease or disorder.
An identifiable segment of DNA (e.g., Single Nucleotide Polymorphism [SNP], Restriction Fragment Length Polymorphism [RFLP], Variable Number of Tandem Repeats [VNTR], microsatellite) with enough variation between individuals that its inheritance and co-inheritance with alleles of a given gene can be traced; used in linkage analysis.