Prognostic gene alterations and clonal changes in childhood B-ALL.

Area of Science:

• Genomics and Molecular Biology
• Pediatric Oncology
• Hematology

Background:

• Genomic profiling is crucial for classifying leukemia risk, predicting outcomes, and guiding therapy.
• Understanding genetic variations in pediatric B-cell acute lymphoblastic leukemia (B-ALL) is essential for improving patient management.

Purpose of the Study:

• To analyze common leukemia-associated gene variations (CRLF2, JAK2, PAX5, IL7R) and copy number alterations (CNAs) in pediatric B-ALL.
• To evaluate clonal changes from diagnosis to relapse.
• To determine the prognostic value of specific genetic alterations in B-ALL.

Main Methods:

• Deep sequencing was used to detect single nucleotide variations (SNVs) in diagnostic (n=77) and relapsed (n=31) pediatric B-ALL samples.
• Multiplex ligation proximity assay (MLPA) was employed to identify CNAs in genes including CDKN2A/2B, PAX5, and CRLF2.
• Clonal dynamics and their association with clinical outcomes were assessed.

Main Results:

• SNVs were detected in 19% of diagnostic and 15.3% of relapse samples.
• CNAs were present in 55% of diagnostic samples, with CDKN2A/2B, PAX5, and CRLF2 being most frequently affected.
• Relapse samples showed clonal dynamics rather than a significant increase in SNVs or CNAs; CDKN2A/2B alterations and/or JAK2 variations were linked to decreased relapse-free survival, while CRLF2 CNAs predicted better survival.

Conclusions:

• Specific alterations in CDKN2A/2B and CRLF2 have significant prognostic value in pediatric B-ALL.
• Clonal evolution plays a role in relapse, with specific gene variations accumulating or disappearing.
• Integrating genomic data into clinical practice can improve patient stratification and understanding of B-ALL relapse.