TY - GEN
T1 - Fetal sex identification in maternal plasma by means of short tandem repeats on chromosome X
AU - Vecchione, Gennaro
AU - Tomaiuolo, Michela
AU - Sarno, Michelina
AU - Colaizzo, Donatella
AU - Petraroli, Rosella
AU - Matteo, Maria
AU - Greco, Pantaleo
AU - Grandone, Elvira
AU - Margaglione, Maurizio
PY - 2008
Y1 - 2008
N2 - Analysis of fetal DNA in maternal plasma has recently been introduced as a new method for noninvasive prenatal diagnosis. In the majority of cases, the Y chromosome-specific sequences are commonly used as a fetus-specific marker with a high risk of false-negative cases. We attempted to develop a sensitive and reliable X chromosome short tandem repeat (STR) multiplex PCR amplification system that is suitable for the amplification of short-sized templates of free fetal DNA. Because of specific characteristics of fetal DNA in maternal plasma, cell-free fetal DNA is smaller than corresponding maternal DNA, and so we selected 10 X-STR loci in which the allele size was 250 bp. In addition, fetal sex was also investigated using the amelogenin gene in the same multiplex assay. Twenty-six women were enrolled in the study. Eight of 26 total fetuses analyzed were male and 18 were female. In the whole sample, X-STRs were informative with a mean of 4.84 ± 1.43. A mean of 2.67 ± 1.28 X-STR markers per sample (range 1-5) of paternally inherited fetal alleles were detected in pregnant women carrying a female fetus. In all cases, blind determination of fetal sex by means of the identification of amelogenin and X-STR markers was confirmed by fetal karyotyping. This study showed that this noninvasive technique is a reliable and accurate tool to investigate free fetal DNA in pregnancies within the first trimester and could be widely used in clinical research and diagnosis.
AB - Analysis of fetal DNA in maternal plasma has recently been introduced as a new method for noninvasive prenatal diagnosis. In the majority of cases, the Y chromosome-specific sequences are commonly used as a fetus-specific marker with a high risk of false-negative cases. We attempted to develop a sensitive and reliable X chromosome short tandem repeat (STR) multiplex PCR amplification system that is suitable for the amplification of short-sized templates of free fetal DNA. Because of specific characteristics of fetal DNA in maternal plasma, cell-free fetal DNA is smaller than corresponding maternal DNA, and so we selected 10 X-STR loci in which the allele size was 250 bp. In addition, fetal sex was also investigated using the amelogenin gene in the same multiplex assay. Twenty-six women were enrolled in the study. Eight of 26 total fetuses analyzed were male and 18 were female. In the whole sample, X-STRs were informative with a mean of 4.84 ± 1.43. A mean of 2.67 ± 1.28 X-STR markers per sample (range 1-5) of paternally inherited fetal alleles were detected in pregnant women carrying a female fetus. In all cases, blind determination of fetal sex by means of the identification of amelogenin and X-STR markers was confirmed by fetal karyotyping. This study showed that this noninvasive technique is a reliable and accurate tool to investigate free fetal DNA in pregnancies within the first trimester and could be widely used in clinical research and diagnosis.
KW - Fetal sex
KW - Maternal plasma
KW - X chromosome short tandem repeat
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U2 - 10.1196/annals.1448.038
DO - 10.1196/annals.1448.038
M3 - Conference contribution
C2 - 18837940
AN - SCOPUS:52249091359
SN - 9781573317344
VL - 1137
T3 - Annals of the New York Academy of Sciences
SP - 148
EP - 156
BT - Annals of the New York Academy of Sciences
ER -