Significance of DNA study in childhood acute lymphocytic leukemia

ABSTRACT

Acute lymphoblastic leukemia [ALL] is the most common malignant disease affecting children, accounting for approximately 30% of childhood cancers. The potential for clinical cure is correlated with a number of prognostic variables. These variables include clinical parameters at the time of diagnosis [e.g. age and white blood cell count], and biologic features of leukemic cells [cytogenetics and DNA content]. This prospective study was conducted on 22 Egyptian leukemic patients. All patients were subjected to complete history and physical examination, chest X-ray, abdominal sonography, complete blood count, bone marrow examination and karyotypic study. Cases were classified into group I [group of good prognosis] and group II [group of bad prognosis] according to their follow up for one year after initiation of treatment. Group I consisted of 11 cases, 10 of them were of normal karyotype and one case showed hyperdiploid >/= 50 chromosomes. Group II consisted of 11 cases, where 2 of them were hyperdiploid [from 46 - 49 chromosome], 2 cases were hypodiploid, 6 cases showed translocations and one case showed deletion of the short arm of chromosome No. 9. One year survival rate was 100% to 10 patients with normal karyotype and 100% to 5 patients with numerical chromosomal abnormalities. Five cases with structural chromosomal abnormalities died [71.4%] out of the 7 detected cases. There is a strong association between certain chromosomal abnormalities and bad prognosis which can be of much benefit in dealing with leukemic children