Fluorescence in situ hybridization (FISH) as a method to detect aneuploid cells.
OBJECTIVE
To test the sensitivity and specificity of various FISH probes for detecting male and aneuploid cells and to determine the percentage of fetal cells that must be present in a sample in order to use the probes for prenatal diagnosis.


METHODS
Adult human lymphocytes were cultured and harvested. Twelve different proportions of male to female cells and 5 different proportions of trisomy 21 cells and trisomy 18 cells in euploid cells were prepared for FISH. Alpha-satellite DYZ1 was applied to detect the male cells. Chromosome 21/Down syndrome critical region cosmid and D13Z1/D21Z1 alpha-satellite probes were applied to detect trisomy 21 cells. The D18Z1 alpha-satellite probe was used to detect trisomy 18 cells.


RESULTS
DYZ1 detected male cells reliably in concentrations as low as 2%. Both D18Z1 and chromosome 21/Down syndrome critical region cosmid probes could detect aneuploid cells at reasonably achievable concentrations. However, the D13Z1/D21Z1 probe was not sensitive below concentrations of 50%.


CONCLUSIONS
FISH is an alternative technique for noninvasive prenatal diagnosis. The sensitivity and specificity of FISH probes may play a crucial role in the accuracy of prenatal diagnosis.
Wei
H J
HJ
Department of Obstetrics and Gynecology, Taipei Medical College Hospital, Taiwan.
Su
T H
TH
Chien
C L
CL
Tzeng
C R
CR
D000328:Adult; D000782:Aneuploidy; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D008214:Lymphocytes / Q000166:cytology*; D008297:Male; D018895:Microsatellite Repeats; D012680:Sensitivity and Specificity; D014314:Trisomy / Q000235:genetics*