Perinatal findings and molecular cytogenetic analysis of de novo partial trisomy 16q (16q22.1-->qter) and partial monosomy 20q (20q13.3-->qter).
OBJECTIVE
To present the perinatal findings and molecular cytogenetic analysis of de novo partial trisomy 16q and partial monosomy 20q and a review of the literature.


METHODS
Obstetric ultrasound at 33 weeks' gestation revealed intrauterine growth restriction (IUGR) and dolichocephaly in a 27-year-old primigravid woman. Prenatal cytogenetic diagnosis was not offered because of the late stage of gestation. A 2800-g male baby was delivered at 41 weeks' gestation by cesarean section because of fetal distress. The infant postnatally presented characteristic craniofacial dysmorphism, hypotonia, cleft palate, congenital heart defects, a subependymal cyst, and hypospadia. Cytogenetic analysis revealed an additional material attached to the terminal region of chromosome 20q. The parental karyotypes were normal. Spectral karyotyping (SKY), fluorescence in situ hybridization (FISH), and polymorphic DNA markers were used to investigate the origin of the de novo aberrant chromosome.


RESULTS
SKY using 24-color probes, FISH using specific 16p, 16q, 20 centromeric, and 20q telomeric probes, and polymorphic DNA marker analysis confirmed maternal origin of the duplication of distal 16q and the deletion of terminal 20q. Karyotype of the proband was designated as 46,XY.ish der(20)t(16;20)(q22.1;q13.3)(SKY+,16qTEL+,20qTEL-).


CONCLUSIONS
Partial trisomy 16q (16q22.1-->qter) and partial monosomy 20q (20q13.3-->qter) may be associated with the perinatal findings of IUGR, dolichocephaly, hypotonia, cleft palate, congenital heart defects, a subependymal cyst, and hypospadia. SKY, FISH, and genetic marker studies help in delineating the parental origin and the regions of the deletion and duplication in the de novo unbalanced translocation.
Chen
Chih-Ping
CP
Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China. cpc_mmh@yahoo.com
Lin
Shuan-Pei
SP
Lin
Chyi-Chyang
CC
Li
Yueh-Chun
YC
Chern
Schu-Rern
SR
Chen
Wei-Min
WM
Lee
Chen-Chi
CC
Hsieh
Lie-Jiau
LJ
Wang
Wayseen
W
D000015:Abnormalities, Multiple / Q000175:diagnosis / Q000000981:diagnostic imaging; D000328:Adult; D002872:Chromosome Deletion; D002885:Chromosomes, Human, Pair 16; D002890:Chromosomes, Human, Pair 20; D020732:Cytogenetic Analysis; D004247:DNA / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D005317:Fetal Growth Retardation / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D019767:Maxillofacial Abnormalities / Q000175:diagnosis / Q000000981:diagnostic imaging; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D014314:Trisomy / Q000175:diagnosis*; D016216:Ultrasonography, Prenatal
D004247:DNA