Comparative genomic hybridization in pediatric acute lymphoblastic leukemia

Comparative genomic hybridization (CGH) was used to clarify the chromosomal status of 15 patients diagnosed with childhood acute lymphoblastic leukemi a (ALL). Bone marrow samples from 10 of the 15 patients were selected becau se no metaphases were obtained for cytogenetic analysis. Three patients wit h normal trypsin and giemsa banding (GTG) karyotypes were also studied by C GH to determine whether significant abnormalities might have been missed by banding analysis, and samples from an additional 2 patients with hyperdipl oidy were also included. Seven of the 10 patients with failed GTG banding a nalysis were found to be chromosomally abnormal by CGH; 2 out of 3 patients with normal GTG band karyotypes were abnormal, indicating that the metapha ses available for karyotyping were not malignant cells, and that CGH analys is of hyperdiploid samples provided more accurate resolution than karyotypi ng alone. The prognostic value of chromosomal aberrations defected by CGH a nd the efficiency of the technique suggest a central role for CGH in routin e clinical cytogenetics.