Prenatal sex determination from maternal peripheral blood using the polymerase chain reaction.
We have investigated the use of a nested polymerase chain reaction assay for the detection of a fetal-specific Y-chromosomal sequence (DYS14) from DNA extracted from unsorted maternal peripheral blood. Serial dilutions of male DNA into female cord blood DNA indicated that the assay could detect an equivalent of a single male cell in 300,000 female cells. The assay exhibited absolute specificity for male DNA with no amplification from a DNA panel obtained from 10 female cord blood samples. When used on DNA extracted from unsorted peripheral blood from a series of pregnant women, the predictive values of a positive test for a male fetus were 86%, 67% and 87% in the first, second and third trimesters, respectively. We have also demonstrated that retesting the samples allows the detection of a proportion of male-bearing pregnancies with a high degree of accuracy, in that all 15 women who gave positive signals in two consecutive amplifications had male fetuses. We have also applied the test at 8 weeks postpartum to eight women who had previously delivered male babies; no Y-specific signal could be detected in any of them, suggesting that most women have cleared their circulation of fetal cells by 8 weeks after parturition.
Lo
Y M
YM
Nuffield Department of Pathology and Bacteriology, John Radcliffe Hospital, Oxford, UK.
Patel
P
P
Baigent
C N
CN
Gillmer
M D
MD
Chamberlain
P
P
Travi
M
M
Sampietro
M
M
Wainscoat
J S
JS
Fleming
K A
KA
D001483:Base Sequence; D004247:DNA / Q000032:analysis; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005865:Gestational Age; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012732:Sex Determination Analysis / Q000379:methods*; D014998:Y Chromosome / Q000737:chemistry*
D004247:DNA