Analysis of Epstein-Barr virus gene polymorphisms in normal donors and in virus-associated tumors from different geographical locations

While Epstein-Barr virus (EBV) infection is associated with the development of certain lymphoid and epithelial tumors, the role of the virus in the pathogenesis of these malignan-cies remains unknown. It has been suggested that EBV strain variation may contribute to tumor development. Two major strains of EBV, type 1 and type 2, have been identified on the basis of genetic polymorphisms and other minor ge-netic variations give rise to distinct EBV isolates. We ana-lyzed EBV strain variation in healthy individuals and com-pared them with EBV isolates present in lymphoid and epithelial neoplasms from the same geographic regions. In particular, the incidence of the 30-bp latent membrane pro-tein (LMP1) gene deletion, recently implicated in the devel-opment of more aggressive forms of virus-positive lympho-PSTEIN-BARR virus (EBV) is a ubiquitous human her- E pes virus that is found as a widespread infection in al