The present invention provides a method for the diagnosis or prognosis of pediatric high hyperdiploid acute lymphoblastic leukemia (HeH-ALL) in a patient, comprising providing a sample from a patient； carrying out simultaneous iFISH with chromosome specific probes labeled with fluorophores of different colors； determining the gain of the labeled chromosomes in every cells； and diagnosing the patient for the presence of HeH-ALL if the incidence of the possible chromosome gain combinations has the predetermined ratio.
