Two cases of non-Hodgkin's lymphoma in first degree relatives.

Two cases of non-Hodgkin's lymphoma (NHL) generated within 6 months in first degree relatives, a father and a son, are presented. The NHL was a diffuse large B-cell type in the father and a small cleaved follicular type in the son. Cytogenetic and molecular studies of the lymphoma cells revealed the rearrangement of the immunoglobulin heavy chain (JH) gene in both patients, the mutation of p53 gene in the father and t(14; 18) (q32; q21) in the son. Both patients had low serum immunoglobulin levels. It is not known whether the occurrence of NHL in this family was incidental or pathogenetically related, since there was no clear common molecular abnormality between the father and the son. The pathogenetic mechanism of this familial occurrence of NHL is discussed.