We have studied 21 families with Wilson disease (WND), using restriction fragment length polymorphisms (RFLPs) in the 13q14.3 region, to measure linkage of these markers to the disease locus. In addition to previously described markers, we include linkage data for a newly isolated marker (D13S86) and an established marker (D13S56), which were previously not placed on the genetic map in the region of the WND locus. Our data, including those from two recombinant families, support the location of WND between the markers D13S31 and D13S59. We have examined the distribution of marker alleles at the loci studied and have found that D13S31 and D13S228, and associated microsatellite marker, show a non-random distribution on chromosomes carrying the WND mutation. The significant linkage disequilibrium indicates that these two markers must be close to the WND locus.