Isochromosome 9q as a sole anomaly in an Omani boy with acute lymphoblastic leukaemia

Abstract

This report describes a case of acute lymphoblastic leukaemia in which isochromosome 9q (i(9q)) was the sole acquired cytogenetic abnormality. The Immunophenotype showed positivity for CD3, CD4, CD5, CD7, CD8, CD10, CD71, CD117 and TdT, consistent with T cell acute lymphoblastic leukaemia (ALL). The chromosomal analysis of bone marrow showed 46,XY,i(9)(q10) in all the metaphases analysed. The bone marrow morphology was ALL-L2 as per the French-American-British criteria. Isochromosomes are rare chromosomal abnormalities in childhood ALL and the effect of i(9q) is not well established. The patient's good response to therapy with normal cytogenetics within a month of induction, and disease-free survival after bone marrow transplant are indicative of a good prognosis in such cases.

Copy number gain of JAK2 on marker chromosome in a case of relapsed pediatric B‐ALL

“…All other abnormalities were confirmed by metaphase FISH (Figure 1E According to literature, only 1%-4% of ALL's have isochromosomes, of which iso9q is most prevalent. 6 However, unlike the present case, iso9q is a rare finding at baseline. 7 On the contrary, trisomy 21 is more frequent and found in ∼30% cases.…”

“…A marker chromosome is defined as a small chromosome fragment that is unidentifiable without genomic characterization. In the current case, four copies of JAK2 genes were observed-two on the marker chromosome and one each on der(9) and der (6). In literature, there is no evidence of copy number gain of JAK2 in ALL on multiple derivative chromosomes or more so, composed as a marker chromosome.…”

B-Lymphoblastic Leukemia Presenting with an Isoderivative Philadelphia Chromosome—A Rare Case Report and Review of Literature

“…Few cases were reported with isochromosome 9 with Phþ in pediatric ALL patients. [9][10][11][12] However, the isochromosome of the long arm of derivative chromosome 22 from t (9;22) with a deletion of 22p, ider(22)(q10)t(9;22) is very rare. To the best of our knowledge, this is the third case of ider (22) in B-ALL; the first case was reported by Yamamoto et al and the second case was of an adult woman with ider(22) with Phþ B-ALL was reported by Meza-Espinoza et al 13,14 Yamamoto et al 13 reported the first case of ider(22) chromosome in acute leukemia similar to this case.…”