A deoxyribonucleic acid (DNA) sequence that is associated with the presence of or vulnerability to a disease. More often than not, the abnormality is not the gene actually responsible for the disorder but a DNA segment that remains physically close to the responsible gene and thus signals the presence of that gene.
An observable trait or physical property that identifies or is associated with a specific region of the genetic material (DNA); a molecular signpost.
Specific gene that produces a recognizable trait and can be used in family or population studies, e.g., to determine susceptibility to a certain disease.
An identifiable physical location on a chromosome (e.g., a gene or segment of DNA with no known coding function) whose inheritance can be monitored.