CONSTRUCTION OF A 3.7-MB PHYSICAL MAP WITHIN HUMAN-CHROMOSOME 20P12 ORDERING 18 MARKERS IN THE ALAGILLE SYNDROME LOCUS

Alagille syndrome (AGS, MIM 118450) is associated with human chromosom e band 20p12. To study this region, we constructed a 3.7-Mb physical m ap using 36 YACs isolated from the CEPH YAC library with three sequenc e-tagged sites (STS): D20S503, D20S41, and D20S188. New STSs were obta ined from 6 isolated YAC end-fragments. Eighteen markers were ordered on the contig as follows: 20ptel-D20S177-D20S175-D20S509 D20S5/D20S503 -D20S506-D20S162-D20S504- 0S6-D20S27-D20S189)-D20S186-D20S41-D20S61-D2 0S492- D20S508-20pcen. A restriction map with the enzymes Asci, MluI, NotI, SacII, and SfiI was generated, revealing seven putative CpG isla nds. We established a YAC contig that spans the AGS region and thus wi ll be valuable for cloning candidate genes and searching for DNA polym orphisms segregating with this syndrome. (C) 1995 Academic Press, Inc.