| DETERMINATION
OF THE FETAL SEX AND PRENATAL DIAGNOSIS OF HEMOPHILIA A |
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| In women who carry the gene of hemophilia,
the prenatal diagnosis is performed in the I and III trimester
of the pregnancy, through the collection of samples from the fetus
like villus chorionic or amniotic fluid. Both the villus chorionic
sampling and the amniocentesis are invasive tests which pose the
danger of abortion in the 0.5-1% of cases. |
| For the past few years, new, less invasive
sampling techniques are being studied. They offer an early diagnosis
method (I trimester period) and immediate results, with the advantage
of reducing the psychological stress and the anxiety in pregnant
women. These techniques are based on the recent discovery that
free cells with fetal origin are already present in maternal blood
since the forth week of pregnancy. |
| The determination of the fetal sex in women
carrying genetic recessive diseases related to the X gene will
be possible through fetal DNA extraction from the plasma or maternal
serum and the amplification of specifics sequences of DNA in the
chromosome Y. Quantitative Real-Time PCR, fluorescence-based polymerase
chain reaction and nested-PCR are techniques that are reported
in the literature for the determination of the fetal sex in the
plasma or in the maternal serum. |
Theses methods offer to carriers of hemophilia
a less invasive way to determine the fetus's sex. This would eliminate
the risks associated with the procedure of invasive diagnosis
and offer the possibility of an early diagnosis (I trimester)
which yields its results in a short time.
The employment of techniques with high throughput permits a prenatal
diagnosis of the hemophilia directly on the fetal DNA, extracted
from the mother's peripheral blood sample. |
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