Cluster analysis of BAC array clones from the 71 regional aberrations in 106 cases. The K-medoids algorithm (where K = 5) was applied to cluster both 106 cases (x axis) and 4912 BAC clones derived from 71 regions of aberrations. Four distinct clusters, +1q, +6p and 6q−, +7, and +18, were identified. The rest exhibited no obvious pattern of aberrations.