Prenatal diagnosis and molecular cytogenetic analysis of partial monosomy 10q (10q25.3-->qter) and partial trisomy 18q (18q23-->qter) in a fetus associated with cystic hygroma and ambiguous genitalia.
OBJECTIVE
To present the prenatal diagnosis and molecular cytogenetic analysis of a fetus with nuchal cystic hygroma and ambiguous genitalia.


METHODS
Amniocentesis was performed at 16 weeks' gestation because of the abnormal fetal sonographic finding of a large septated nuchal cystic hygroma. Genetic amniocentesis revealed a terminal deletion in the long arm of chromosome 10. The paternal karyotype was subsequently found to be 46,XY,t(10;18)(q25.3;q23). The maternal karyotype was normal. The pregnancy was terminated. A hydropic fetus was delivered with a septated nuchal cystic hygroma and ambiguous genitalia. Fluorescence in situ hybridization (FISH), microarray-based comparative genomic hybridization (CGH), and polymorphic DNA markers were used to investigate the involved chromosomal segments.


RESULTS
FISH study showed absence of the 10q telomeric probe and presence of the 18q telomeric probe in the derivative chromosome 10. Microarray-based CGH analysis showed loss of distal 10q and gain of distal 18q. Polymorphic DNA marker analysis determined the breakpoints. The fetal karyotype was 46,XY,der(10)t(10;18)(q25.3;q23)pat. The chromosome aberration resulted in partial monosomy 10q (10q25.3-->qter) and partial trisomy 18q (18q23-->qter).


CONCLUSIONS
The present case provides evidence that partial monosomy 10q (10q25.3-->qter) with partial trisomy 18q (18q23-->qter) can be a genetic cause of fetal cystic hygroma and ambiguous genitalia. Cytogenetic analysis for prenatally detected structural abnormalities may detect unexpected inherited chromosome aberrations.
Chen
Chih-Ping
CP
Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China. cpc_mmh@yahoo.com
Chern
Schu-Rern
SR
Wang
Tzu-Hao
TH
Hsueh
Ding-Wei
DW
Lee
Chen-Chi
CC
Town
Dai-Dyi
DD
Wang
Wayseen
W
Ko
Tsang-Ming
TM
D000328:Adult; D002879:Chromosomes, Human, Pair 10 / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D020732:Cytogenetic Analysis; D005260:Female; D005835:Genitalia / Q000002:abnormalities*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D018191:Lymphangioma, Cystic / Q000235:genetics*; D009006:Monosomy / Q000175:diagnosis*; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014314:Trisomy / Q000175:diagnosis*