The fetus in the first case presented cebocephaly,
semilobar holoprosencephaly, and
tetralogy of Fallot on ultrasound at 25 gestational weeks. Cordocentesis using multiplex
ligation-dependent probe amplification to detect
aneuploidies of chromosomes X, Y, 13, 18, and 21 in uncultured cord blood revealed three copies of all targets on chromosome 13 consistent with the diagnosis of
trisomy 13. The fetus in the second case presented bilateral choroid plexus
cysts,
congenital diaphragmatic hernia, and club foot on ultrasound at 18 gestational weeks. Amniocentesis using array-based comparative genomic hybridization (aCGH) in uncultured amniocytes revealed a gain in the
DNA dosage of chromosome 18 consistent with the diagnosis of
trisomy 18. The fetus in the third case presented
aortic stenosis and nuchal
edema on ultrasound at 22 gestational weeks. Amniocentesis using aCGH in uncultured amniocytes revealed a result of
monosomy X and
Turner syndrome. The fetus in the fourth case presented nuchal
cystic hygroma and ventriculomegaly on ultrasound
at 17 gestational weeks. Amniocentesis using aCGH in uncultured amniocytes revealed a gain in the
DNA dosage of chromosome 21 consistent with the diagnosis of
trisomy 21. The fetus in the fifth case presented
holoprosencephaly,
omphalocele, and
hydronephrosis on ultrasound
at 17 gestational weeks. Amniocentesis using aCGH in uncultured amniocytes revealed a gain in the
DNA dosage of chromosome 13 consistent with the diagnosis of
trisomy 13.
CONCLUSIONS: Prenatal diagnosis of major congenital malformations should alert one to the possibility of
chromosomal abnormalities. Multiplex
ligation-dependent probe amplification and aCGH have the advantage of rapid
aneuploidy diagnosis of common
aneuploidies in cases with major congenital malformations.