Mapping genetic systems by the supratype method

Summary Kinship mapping and population supratypes provide information on order and relative genetic position of loci within a system too small to map by recombination. These methods are compared for the RH, -globin, HLA, and GM systems, where recombination between loci is estimated as 0.0002–0.0069. Supratype analysis does not appreciably improve kinship mapping. Mean recombination within systems appears to be 10^-4 morgans/kb, an order of magnitude greater than the average for the whole genome. Possible implications of this discrepancy are discussed.