Near haploid childhood acute lymphoblastic leukemia masked by hyperdiploid line: detection by fluorescence in situ hybridization

• Published in: Cancer genetics and cytogenetics 2001-07, Vol.128 (2), p.108-113
• Main Authors: Stark, Batia, Jeison, Marta, Gobuzov, Rima, Krug, Hagit, Glaser-Gabay, Leticia, Luria, Drorit, El-Hasid, Ronit, Harush, Miriam Ben, Avrahami, Gali, Fisher, Salvador, Stein, Jerry, Zaizov, Rina, Yaniv, Isaac
• Format: Article
• Language: English
• Subjects: Adolescent; Biological and medical sciences; Child; Diploidy; Female; Haploidy; Hematologic and hematopoietic diseases; Humans; In Situ Hybridization, Fluorescence; Karyotyping; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Male; Medical sciences; Precursor Cell Lymphoblastic Leukemia-Lymphoma - drug therapy; Precursor Cell Lymphoblastic Leukemia-Lymphoma - genetics; Treatment Outcome
• ISSN: 0165-4608; 1873-4456
• DOI: 10.1016/S0165-4608(01)00411-3

Near-haploid (50 chromosomes) ALL. We present three children in whom, by conventional cytogenetics, near-haploid ALL was detected on relapse. Using interphase FISH probes of chromosomes X, Y, 4, 12, and 21, we were able, in two cases, to trace the hidden near-haploid lines of approximately 5% and 20% of the cells, masked by hyperdiploid cells of approximately 80% and 70%, respectively; at relapse, the proportion was reversed, with predominant near-haploid lines of over 80% and residual hyperdiploidy of less than 10%. The near-haploid lines consisted of 24 and 27 chromosomes, and always retained the second copy of chromosome 21 or its derivative, as detected in one of our patients by SKY. The hyperdiploid clones were the exact duplicates of the near-haploid ones and contained four and two copies of the chromosomes represented in two and one copies in the near-haploid stem line, respectively. Unlike the common hyperdiploid ALL, no trisomies were observed. The patients were all aged >10 years, with WBC 0.7–30 × 10 9/L, and a common ALL phenotype. They were treated with the ALL-BFM-95 protocol, medium risk group, and responded well to 8 days of steroid therapy, but relapsed early, within 11 months, and died a few months later. Interphase FISH technique is recommended for the detection of cryptic near-haploid clones in the diagnostic survey of ALL. To assess the prognostic value of near-haploidy in the context of the ALL-BFM protocols, a larger cohort of patients is required.