CLONE-CONTIG AND STS MAPS OF THE HEREDITARY HEMOCHROMATOSIS REGION ONHUMAN-CHROMOSOME 6P21.3-P22

YAC-based and bacterial-clone based STS-content maps were constructed that served as the Framework physical maps for the positional cloning of a candidate gene for hereditary hemochromatosis. The YAC-based map comprises 43 YACs and 86 STS and spans -8 Mb of DNA between the class region of the major histocompatibility complex on human chromosome 6p2 1.3 and D65276 in 6p22. Comparison with published maps revealed a hole in the MIT/Whitehead and CEPH YAC maps that includes the immediate re gion around the hemochromatosis gene itself. Approximately 3 Mb of DNA was covered by a bacterial clone contig that consists of 38 BACs, 45 PACs, 26 PI clones and one lambda phage. The bacterial clone-based STS map comprises 153 STSs. A contiguous block of 8 STSs could be amplifi ed from both human chromosome 6 and 5. Further characterization of sel ected STSs and bacterial clones by radiation hybrid mapping and fluore scence in situ hybridization, respectively, revealed the presence of a multicopy DNA segment, more than one bacterial clone length in size, which is duplicated near the chromosome-6 centromere and part of which is present in multiple copies on chromosome 5. Possible implications of the incomplete public YAC-contig map and of the multicopy segment f or physical mapping and linkage disequilibrium studies of the hemochro matosis candidate region are discussed.