Five patients, cured from acute lymphoblastic leukaemia (ALL), four women and one man, have seven healthy children: four girls and three boys. The children were born in the period from 13 to 25 years since the beginning of the disease and 5 to 16 years after cessation of monotherapy. Age of the children varied from 2 to 13 years. In two patients and in their children an inversion or a partial inversion of the heterochromatic region of chromosome 9 was observed.