Detection of N-RAS gene mutations in codons 12,13 and 61 in patients with pediatric acute lymphoblastic leukemia

Acute leukemia is the prevalent malignancy in pediatrics. One of the most important causing factors of acute lymphoblastic leukemia is mutations of proto oncogenes and their chang in to oncogenes. Activation of N-RAS proto-oncogene due to point mutations plays a major role in ALL malignancy. Since there was no report on the frequency of N-RAS gene mutation in Iranian pediatric ALL patients, therefore we decided to determine its frequency and compare the results with age, sex and type of ALL. In this study, 60 pediatric ALL patients from Tehran Mahak hospital were screened for the mutations of N-RAS gene at codons 12, 13 1nd 61.DNA was extracted from peripheral blood samples before the start of chemotherapy. The above mentioned codons were amplified by PCR and analyzed by restriction endonuclease enzymes. We could detect mutations in 7 cases of 60(11.7%) patients. Most of the mutations were detected in males with an age less than 5 years old. The frequency of mutations for codons 12, 13 and 61 were 8.3%,3.3% and 1.7% respectively. Most of the mutations (71.4%) were found in c-ALL subtype. We detected mutations in 11.7% of our ALL patients. In general, frequency of the mutations that we found was in agreement with the results of other studies. However, to do study with more patients and wider range of age using a combination of PCR-RFLP and direct gene sequencing is highly recommended.