Construction of an Integrated Physical and Gene Map of Human Chromosome 20p12 Providing Candidate Genes for Alagille Syndrome

Physical mapping and localization of eSTS markers were used to generate an integrated physical and gene map covering a ∼10-Mb region of human chromosome 20p12 containing the Alagille syndrome (AGS) locus. Seventy-four STSs, 28 of which were derived from cDNA sequences, mapped with an average resolution of 135 kb. The 28 eSTS markers define 20 genes. Six known genes, namely CHGB, BMP2, PLCB1, PLCB4, SNAP, and HJ1, were precisely mapped. Among the genes identified, one maps in the smallest region of overlap of the deletions associated with AGS and could therefore be regarded as a candidate gene for Alagille syndrome.