The cytogenetic view of standard comparative genomic hybridization (CGH): deletions of 20q in human leukemia as a measure of the sensitivity of the technique.
BACKGROUND
The limits of the resolving power of comparative genomic hybridization (CGH) have been given as 10-20 Mbp if at least 50% of the studied neoplastic cell population carried the corresponding aberration.


METHODS
Genomic DNA of five cases of hematologic neoplasias, in all of which--among other anomalies--deletions of different size of chromosome 20q were found by GTG banding and confirmed by FISH analyses, was subjected to CGH.


RESULTS
CGH revealed four types of del(20q), and, in addition, detected a tiny terminal del(3p) in one of the cases. The size of the smallest deleted segment, clearly visible by eye on the CGH metaphase image, was estimated to range between 5 and 7 Mbp.


CONCLUSIONS
Visual determination was shown to have a stronger resolving power in CGH than software used for the analysis in one case, while in another one, the results obtained from the ratio profiles would have been considered insignificant without the knowledge of the hybridization pattern on the corresponding CGH metaphase images. The potential of the standard CGH technique not only to detect, but visualize small segmental aneusomies as well, suggests that its resolution actually mirrors the resolution of banding techniques.
Brecevic
L
L
Institute of Human Genetics, University of Erlangen-Nürnberg, Schwabachanlage 10, D-91054 Erlangen, Germany.
Verdorfer
I
I
Saul
W
W
Trautmann
U
U
Gebhart
E
E
D002467:Cell Nucleus / Q000648:ultrastructure; D002872:Chromosome Deletion; D002890:Chromosomes, Human, Pair 20; D020732:Cytogenetic Analysis; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007938:Leukemia / Q000235:genetics*; D009693:Nucleic Acid Hybridization / Q000379:methods*; D012680:Sensitivity and Specificity