[Current data on familial occurrence of malignant hematologic diseases in the County of Szabolcs-Szatmár-Bereg in Hungary].

So far the authors have observed 27 cases of accumulation of malignant haematologic diseases within a family in their county. They published the first ten cases in Orvosi Hetilap in 1992. Most often the co-existence of the diseases with the highest incidence (non-Hodgkin's lymphoma, chronic lymphocytic leukaemia, acute leukaemia) was observed, in terms of relationship mostly the parent--child combination was observed. Analyzing the data of parent--child combinations (17 cases) they can notice two remarkable trends: 1. The "malignity degree" of the disease appearing in the second generation is either the same or greater than that of the disease of the first generation (the opposite of this was not experienced in any of the cases!). 2. The disease of the second generation appears mostly at a much younger age than that of the parent. Consequently, they can observe a "double acceleration": the disease tends to be more malignant nearly in the half of the second generation patients, and the disease appears in the children at a much younger age.