Angelman syndrome (AS) is caused by the loss of function of undefined gene(s) on human chromosome 15. The majority of subjects have deletions involving maternally-derived chromosome 15q11-q13, and the shortest region of deletion overlap (SRO) has been localized to the region between D15S10 and D15S113. In this study, yeast artificial chromosomes (YACs), 6G-D4, 9H-D2 and 37D-F9, mapping within the AS SRO, were isolated from the ICI YAC library. Alu-vector PCR products were amplified from the YACs and from YACs A229A2 and A33F10 which had been obtained from the St. Louis YAC library. The PCR products were cloned and sequenced, and three new sequence-tagged sites were generated within the AS SRO, facilitating the characterization of gene(s) involved in the Angelman syndrome.