Gametic disequilibrium and physical distance.

The relationship between gametic disequilibrium and physical distance between RFLPs at different gene regions is of great interest due to the current research in fine gene mapping. A recent review found that gametic disequilibrium nearly always correlates significantly with physical distance in genomic regions greater than 50 to 60 kb in size, but it does not do so in smaller genomic regions. This conclusion is based on an analysis which is inappropriate as the r disequilibrium coefficient is frequency dependent, which disqualifies it from comparing disequilibrium between pairs of loci with different allelic frequencies. 11 refs., 2 tabs.