High-throughput genomic analysis in Waldenström's macroglobulinemia

Single-nucleotide polymorphism array (SNPa) and array-based comparative genomic hybridization (aCGH) are among the most sensitive genomic high-throughput screening techniques used in the exploration of genetic abnormalities in Waldenström's macroglobulinemia (WM). SNP and aCGH allow the identification of copy number abnormalities (CNA) at the kilobase level thus identifying cryptic genetic abnormalities unseen by lower-resolution approaches such as conventional cytogenetic or fluorescence in situ hybridization (FISH). CNA were identified in nearly 80% of cases by aCGH that delineated in addition minimal altered regions. At gene level, remarkable findings affecting genes involved in the regulation of the NF-kB signaling pathways were identified, such as biallelic inactivation of TNFAIP3 and TRAF3. SNPa also allowed characterization of copy neutral losses such as uniparental disomies (UPD), which is an important and frequent mechanism of gene alteration in cancer cells. Herein, we summarize the current knowledge of WM genomic basis using these high-throughput techniques.