Characterization of 6q deletions in mature B cell lymphomas and childhood acute lymphoblastic leukemia

The study was undertaken with the aim to outline deletion patterns involving the long arm of chromosome 6, a common abnormality in lymphoproliferative disorders. Using a chromosome 6 specific tile path array, 60 samples from in total 49 cases with mantle cell lymphoma (MCL), de novo diffuse large B-cell lymphoma (DLBCL), transformed DLBCL as well as preceding follicular lymphoma (FL), and childhood acute lymphoblastic leukemia (ALL), were characterized. Twenty-six of the studied cases, representing all diagnoses, showed a 6q deletion among which 85% involved a 3 Mb region in 6q21. The minimal deleted interval in 6q21 encompasses the FOXO3A, PRDM1 and HACE1 candidate genes. The PRDM1 gene was found homozygously deleted in a case of DLBCL. Moreover, in two DLBCL cases, an overlapping homozygous deletion was identified in 6q23.3 - 24.1, encompassing the TNFAIP3 gene among others. Taken together, we refined the deletion pattern within the long arm of chromosome 6 in four different types of hematological malignances, suggesting the location of tumor suppressor genes involved in the tumor progression.