Intrachromosomal amplification of RUNX1 gene (iAMP21) on chromosome 21 in pediatric acute lymphoblastic leukemia

Abstract

The spectrum of acute lymphoblastic leukemia genetic abnormalities is rapidly expanding. Therefore, newly detected chromosomal aberrations are likely to have an impact on clinical care in the near future. Recently, iAMP21 started to be considered a high-risk chromosomal abnormality. It occurs in approximately 2-5% of pediatric BCP-ALL. This abnormality is associated with a poor prognosis and increasing risk of relapse. Hence, an accurate detection of this aberration is expected to become very important in the choice of appropriate therapy. In this work the clinical and molecular cytogenetic evaluation by FISH technique were done for thirty patients with B-ALL. They were attending Hematology Oncology unit of pediatric Ain Shams University Hospital. Their ages ranged from 1.33 to 16 years with a mean value age of 7.76 years ±5.11. They were 23 males and 7 females with a male to female ratio of 3.2:1. iAMP21 was detected in 11/30 (36.7%) of cases: 9/30 (30%) revealed amplification without t(12; 21), and 2/30 (6.7%) revealed the amplification together with t(12; 21). In our study, cases with positive iAMP21are associated with older age with a mean value 10.7 years.we also observed a significant association between Runx1