[The application of dual-color fluorescence in situ hybridization to the diagnosis of Klinefelter syndrome].
The objective of the work is to study the technique of dual-color fluorescence in situ hybridization(D-FISH) and its application value in the diagnosis of sex chromosomal count abnormality Klinefelter syndrome and establish an experimental approach to metaphase chromosome and interphase nucleus FISH technique. Biotin labeled alpha satellite X-chromosome DNA(pBamX7) probe and Digoxigenin labeled Y-chromosome long arm terminal repetitive sequence (pY3.4) probe were hybridized with pre-treated slides of peripheral blood chromosome and interphase nucleus in 19 cases of Klinefelter syndrome specimens. After being washed,the slides were treated with Avidin-FITC,Rhodamine-FITC and Anti-avidin,amplified with an additional layer and counter-stained with DAPI in an antifade solution. The hybridization signals,chromosomal or interphase nucleus settings were observed respectively with WIB, WIG and WU filters under fluorescence microscope Olympus AX-70,and the number of metaphase chromosome and interphase nucleus in the peripheral blood was counted. It was observed under the microscope that the Biotin labeled pBamX7 probe showed 2 green hybridization signals and that the Digoxigenin labeled pY3.4 probe showed 1 red hybridization signal. Chromosome or interphase nucleus counter-stained with DAPI showed blue. The average signal rate of chromosome and interphase nucleus hybridization was 95.89% and 95% respectively,significantly higher than the normal control (2.75%). Karyotype 47,XXY was confirmed,which agrees with the chromosomal findings. One case showed mosaic nuclei. XXY chromosome hybridization signal rate was 92% and XY hybridization signal rate was 6.7%, higher than the normal control rate of 4.17%. FISH is a valuable technique in diagnosing sex chromosomal count abnormality Klinefelter syndrome with the merits of fast speed, high sensitivity, strong signal,low background and multiple color. Therefore, FISH technique can find wide application and potential in prenatal diagnosis.
Liu
Yong-Zhang
YZ
College of Life Science, Zhejiang University, Hangzhou, Zhejiang 310012, China. Liuyz-2@163.com
Wu
Xue-Chang
XC
Jin
Long-Jin
LJ
Dong
Jie-Ying
JY