[Detection of K-ras and p-53 oncogene mutations in a patient with acute lymphoblastic leukemia before and after bone...

We present a case of 22 years old male patient, who was submitted to singenic transplantation of hematopoietic cells originating from the bone marrow in the remission phase of the diagnosed acute lymphoblastic leukemia (ALL). The bone marrow sample was donated by his healthy twin brother. The pretransplantation and transplantation phases were regular. We analyzed the presence of K-ras and p-53 point mutations in our patient with ALL and for the first time we had the opportunity to analyze the samples from two monozygotic twins. DNA was isolated from the peripheral blood mononuclear cells (PBMNC) by the standard procedure, of the patient with ALL before and after bone marrow (BM) transplantation and of his clinically healthy twin brother. Samples were subjected to PCR amplification of K-ras exons 1 and 2 and p-53 exons 5, 6, 7 and 8. In PBMNC of the patient with ALL before BM transplantation, mutations were observed in exon 1 of K-ras and exon 8 of p-53 gene. These mutations were found neither in PBMNC sample of his twin brother, nor in PBMNC of the patient with ALL after BM transplantation. In the p-53 exons 5, 6 and 7 and exon 2 of K-ras, there were no mutations in any analyzed samples. Detected mutations in K-ras and p-53 genes could be a part of larger genetic abnormalities and the obtained results had shown the possibility of using DNA mutational changes in the follow-up of the success of BM transplantation. The molecular disease marker that was found by this method was also significant for the detection of minimal residual disease at the molecular level.