Exclusion mapping illustrated by the MNSs blood group

Summary An exclusion mapping method is described which attempts to combine in a compact form negative information from deletion studies and studies on families segregating for existing reference markers, centromere markers and familial translocations. A meiotic map is provided for exclusion mapping. Chromosome 22 is used as a worked example of the exclusion mapping of the MNSs blood group. A particular assignment for MNSs to the q28 or q31 region of chromosome 4 is suggested by this method.