Identifying chromosomal fragile sites from a hierarchical-clustering pointof view

Identification of fragile sites is a way to investigate the genetic abnorma lities that are the hallmark of cancer and play an important role in carcin ogenesis. Manifestation of nonrandom breakage at a chromosome band is an es sential criterion for determination of the fragility of the band. In this a rticle. a new detection procedure is proposed. This new procedure takes the relationship of one site with the others into consideration and can be app lied to tests of the randomness of breakpoints under either the proportiona l probability model (PPM) or the equiprobability model (EPM). The procedure can form a grouping structure that classifies all sites into several clust ers. It is applied to identification of fragile sites for a real data set f or Chinese patients with colorectal carcinoma for illustration of the propo sed method.