IKZF1 Alteration in Pediatric B-Cell Acute Lymphoblastic Leukemia: A Single-Center Report on the Frequency of IKZF1 Deletions and Its Subtypes

The most prevalent malignancy during childhood is B-cell acute lymphoblastic leukemia (B-ALL). Many genetic variations are the causes of B-ALL. IKZF1 alterations are prevalent in childhood B-ALL cases, which are associated with a poor prognosis. This studyexamined seventy-two pediatric B-ALL patients for the frequency of IKZF1 alteration and types of IKZF1 deletions.

In this study, bone marrow aspirate specimens at the stage of diagnosis in pediatric B–ALL patients were used. The diagnosis of B-ALL was performed following cytomorphology, cytochemistry, and immunophenotyping based on the 2016 World Health Organization (WHO) guidelines. ALL translocations, including TCF3-PBX1 fusion, ETV6-RUNX1 fusion, BCR-ABL1 fusion, and KMT2A-AFF1 fusion, were performed on DNA specimens of all patients. IKZF1 status was checked with the SALSA MLPA P335 ALL-IKZF1 probemix Kit.

The common-B ALL subtype was detected in 64/72 patients (88.9%). CD2 and CD13 aberrant expressions were found in 5/72 (6.9%) and 7/72 patients (9.7%), respectively. Molecular analysis for translocation revealed the frequency of ETV6-RUNX1 in 12/72 patients (16.7%) and BCR-ABL1 in 3/72 (4.2%). IKZF1 alterations were found in 13/72 patients (18%), of whom 10 (13.9%) had IKZF1 deletions. Three common types of IKZF1 deletions were found.

The frequency of IKZF1 deletion in this study is similar to the results already obtained in larger studies. The type of IKZF1 deletion related to poor outcomes has a higher frequency in this study. Because of the relatively high prevalence of IKZF1 deletion, its determination is important for better risk stratification and prognosis in pediatric B-ALL patients.