The distribution of genotype rs7073837 in ARID5B significantly differed between ALL and controls (P=0.046), while those of IKZF1 (rs6964823, rs4132601, and rs6944602) and ARID5B (rs10740055 and rs7089424) did not.
Additionally, to verify whether the risk allele is favored by somatic tumor evolution, we examined the incidence of IKZF1 deletions in leukemic clones derived from 153 previously genotyped cases of pediatric ALL.
We report a specific gene expression signature of 735 up-regulated and 473 down-regulated genes in IKZF1 deleted primary B-ALL pediatric patient samples.
In addition, IKZF1 has been implicated in roles involved in some hematologic traits or abnormalities, such as erythrocyte measures, myelofibrosis, and acute lymphoblastic leukemia (ALL), which may be common clinical manifestations or co-occurrence hematological diseases of patients with SLE.
In contrast, risk of ALL/MLL- was increased in infants homozygous for the IKZF1 variant (OR = 5.1, 95% CI = 1.8-14.5) but the variant did not modify risk of ALL/MLL+.
Case-control comparisons revealed dose-dependent associations between ARID5B rs10821936, ARID5B rs10994982, and IKZF1rs11978267 and childhood ALL overall, and B lineage and B lineage hyperdiploid ALL examined separately (all allelic odds ratios ≥1.33, Ptrend≤0.001).
One recently identified subtype of pediatric B-precursor acute lymphoblastic leukemia (ALL) has been termed BCR-ABL1-like or Ph-like because of similarity of the gene expression profile to BCR-ABL1 positive ALL suggesting the presence of lesions activating tyrosine kinases, frequent alteration of IKZF1, and poor outcome.
We conclude that IKZF1 and TP53 represent relevant prognostic factors that should be considered in future risk assessment of children with relapsed ALL to indicate treatment intensification or intervention.
With logistic regression, we identified 6 SNPs in the ARID5B and IKZF1 genes associated with increased risk to B-cell ALL, and two SNPs in the STAT3 gene, which decreased the risk to hyperdiploid ALL.
We identified CRLF2 overexpression as an intermediate-risk marker and Ik6 variant of IKZF1 gene as a high-risk one when stratifying pediatric B-ALL cases according to cytogenetic/molecular risks.
As controversy exists regarding the prognostic significance of genomic rearrangements of CRLF2 in pediatric B-precursor acute lymphoblastic leukemia (ALL) classified as standard/intermediate-risk (SR) or high-risk (HR), we assessed the prognostic significance of CRLF2 mRNA expression, CRLF2 genomic lesions (IGH@-CRLF2, P2RY8-CRLF2, CRLF2 F232C), deletion/mutation in genes frequently associated with high CRLF2 expression (IKZF1, JAK, IL7R), and minimal residual disease (MRD) in 1061 pediatric ALL patients (499 HR and 562 SR) on COG Trials P9905/P9906.
Mutations in genes regulating lymphoid development are a hallmark of ALL, and alterations of the lymphoid transcription factor gene IKZF1 (IKAROS) are associated with a high risk of treatment failure in B-ALL.
Integrated use of minimal residual disease classification and IKZF1 alteration status accurately predicts 79% of relapses in pediatric acute lymphoblastic leukemia.
Statistically significant association between genotype at 7p12.2 (IKZF1), 10q21.2 (ARID5B) and the NBS associated locus, 8q21.3 (NBN) and ALL risk was found; odds ratios (ORs), 1.34 (P=0.002), 1.33 (P=0.003), and 1325.21 (P=0.0028), respectively.
Notably, genetic alterations targeting transcriptional regulators of lymphoid development are a hallmark of B-progenitor ALL, and alteration of specific genes in this pathway, such as IKZF1 (encoding IKAROS), are associated with high-risk ALL.