Prenatal diagnosis of tetrasomy 9p in a 19-week-old fetus with Dandy-Walker malformation: a case report.
OBJECTIVE
The presentation of sonographic and perinatal findings of tetrasomy 9p.


RESULTS
Chorionic villus sampling and amniocentesis were performed at 19 weeks of gestation because of the sonographic findings of Dandy-Walker malformation with bilateral ventriculomegaly. Cytogenetic analysis showed 47,XX,+i psu dic(9)(pter->q12::q12>-pter). The pregnancy was terminated at 20 weeks of gestation at the request of the parents. At post-mortem examination, the presumed hypoplasia of the vermis could not be confirmed for technical reasons. No other pathological findings were seen.


CONCLUSIONS
From our experience and from the literature, we conclude that Dandy-Walker malformation is an important finding in tetrasomy 9p. Chromosomal studies should be carried out in fetuses with sonographically detected Dandy-Walker malformation, even in the absence of other abnormalities.
Deurloo
K L
KL
Department of Obstetrics and Gynecology, VU University Medical Center, Amsterdam, The Netherlands.
Cobben
J M
JM
Heins
Y M
YM
de Ru
M
M
Wijnaendts
L C D
LC
van Vugt
J M G
JM
D000328:Adult; D000653:Amniotic Fluid / Q000166:cytology; D000782:Aneuploidy; D002899:Chromosomes, Human, Pair 9; D020732:Cytogenetic Analysis / Q000379:methods*; D003616:Dandy-Walker Syndrome / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000196:embryology / Q000235:genetics; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000235:genetics; D005865:Gestational Age; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D011247:Pregnancy; D011296:Prenatal Diagnosis; D016216:Ultrasonography, Prenatal / Q000379:methods