Genome-wide detection of recurring sites of uniparental disomy in folicular and transformed follicular lymphoma

Follicular lymphoma (FL) is the second most common B-cell malignancy representing one quarter of Non-Hodgkin's Lymphomas. Although the disease has a relatively long median survival, the illness follows a fluctuating course of progression punctuated by remissions of variable duration. For as many as half of patients, transformation to a more aggressive lymphoma (t-FL) may occur; this event is often associated with a particularly poor response to treatment. SNP analysis has revealed the presence of large regions of homozygosity in the absence of copy number change. These events can result in the selection of of daughter cells made homozygous for a pre-existing mutation. We have used SNPs array technology to investigate regions of loss of hetrozygosity in the absence of copy number change in order to establish the contribution of these abnormalities to the evolution of FL and t-FL. Keywords: DNA copy number, Loss of heterozygosity DNA from 26 pairs of follicular and transformed follicular lymphoma samples and 3 cell lines were analysed using Affymetrix 10K SNP arrays. The genotype data of transformed follicular lymphoma samples were compared with the data from the corresponding follicular lymphoma sample.