Despite the advances in diagnosis of leukemia, still we need a rapid and cost-benefi t screening method in patients with acute lymphoblastic leukemia (ALL). The aim of the present study is to evaluate the ability of Multiplex Ligationdependent Probe Amplifi cation (MLPA) method in screening patients with ALL. 45 patients with ALL were selected. DNA were extracted, then PAX5 gene copy number abnormalities (CNAs) were studied by adopting MLPA and QPCR methods. To prove the results of two methods, PCR product from three samples were sent for sequencing. From 45 patients with BALL , 11 (24%) patients, showed CNAs after applying MLPA method. From among all mutations, 22 samples (29%) were seen in PAX5 gene. We used Sanger sequencing as a gold standard method to compare the two methods. After sequencing, we were submitted 2 genes in Gene Bank by accession numbers (ID) KX608846 and KX707789 in exon 10 of PAX5. MLPA is a rapid and valid method for screening of genes mutation and can be used in these laboratories as routine method especially in low-income countries.