Quantitative Analysis Of Random Chromosomal Aberrations In PHA-Stimulated Blood and Bone Marrow

Yoon, Hye Ryoung; Kim, Sun Hee

Abstract

BACKGROUND: Chromosomal aberration observed only in a few metaphases may cause the cytogeneticists to have difficulties in making a decision whether it is due to in vivo mosaicism/multiple clones or due to in vitro artifact. This is especially important when the chromosome of concern has been associated with a classical chromosome syndrome, malignancy or its evolution. Therefore, we aimed to establish a range for random chromosomal aberrations among cells from PHA-stimulated blood(PB) and bone marrow(BM) cultures.
METHODS
Among the cells from 449 PB and 472 BM specimens referred for chromosome studies from 1997 to 1998, we analyzed the frequency of random aneuploidy, structural abnormalities, and breaks/gaps.
RESULTS
The number of cells analyzed was 5,904/4,488(1997/1998) in PB and 4,211/4,124(1997/1998) in BM. The frequency of metaphases with random chromosomal aberrations of BM(32.10%) was much higher than that of PB(5.90%). The most frequent aberration was chromsome loss. Autosome losses were inversely correlated with autosome size(correlation coefficient = -0.83 and -0.72, p<0.01), smaller chromosomes being lost more frequently while autosome breaks/gaps were correlated with autosome size(correlation coefficient = 0.69 and 0.85, p<0.01), in PB and BM. Comparing the data from 1998 to the data from 1997, the frequency of chromosome losses(<0.5% in PB, <2.25% in BM), gains(<0.1% in PB and BM), breaks/gaps(<0.1% in PB, <0.25% in BM), and structural aberrations(CONCLUSIONS
The above results could provide fundamental data for making a decision on whether chromosomal aberration in only a few metaphases is true mosaicism/malignant clone or random aberration, saving time and cost. It could also be used as part of our quality control program by consequent comparison with the previous year's data.