Locus (pl. loci): A specific physical position on a chromosome at which a gene or gene pair resides. As scientists map genes to specific chromosomal locations they are registered with the Human Gene Mapping Workshop, assigned a name, and entered onto the genetic map of that chromosome.

Long Arm Statute: A law which permits one State to claim jurisdiction over nonresident parties. There must be some meaningful connection between the person and the State in which the jurisdiction is exercised in order for it to be constitutional to reach beyond the court's normal jurisdictional border.

Linkage Disequilibrium: A specific allele of one locus being found with a specific allele of another locus more often than would be expected by chance. Occurs when the two loci are close together on the same chromosome. They are then said to be linked because they will tend to be inherited together.