Absence of mutations in the NBS1 gene in B-cell malignant lymphoma patients

Background: Nijmegen breakage syndrome (NBS), also known as ataxia-telangie ctasia (AT) variant, is an autosomal recessive disorder characterized by mi crocephaly, growth retardation severe combined immunodeficiency and a high incidence of lymphoid carcinoma, the majority of which are B-cell lymphomas . To determine whether the NBS1 gene is a tumor suppressor gene in B-cell l ymphoma we screened B-cell malignant lymphoma (ML) for any evidence of NBS1 mutation. Materials and methods: Sequence analysis of the NBS1 gene was pe rformed from PCR products amplified from the DNA of 12 extracranial ML or R T=PCR products amplified from cDNA of 8 primary central nervous system lymp homa. Results: Direct sequence analysis revealed that no NBS1 mutations wer e present in any of these patients. Conclusion: The present results suggest ed that the contribution of NBS1 mutations to B-cell ML was minimal, despit e the fact that the NBS1 gene was causative factor in these cases.