Inherited unbalanced structural chromosome abnormalities at prenatal chromosome analysis are rarely ascertained through recurrent miscarriage.
OBJECTIVE
To determine the mode of ascertainment of inherited unbalanced structural chromosome abnormalities detected at prenatal chromosome analysis.


METHODS
From the databases of three centres for clinical genetics in the Netherlands, all cases of inherited unbalanced structural chromosome abnormalities detected at prenatal chromosome analysis in the period 1992-2000 were selected. The mode of ascertainment was identified by examining the reason for prenatal chromosome analysis and the reason for parental chromosome analysis of the first structural chromosome abnormality detected within the family.


RESULTS
Totally 56 cases of inherited unbalanced structural chromosome abnormalities were detected at prenatal chromosome analysis. Only one case was ascertained through two previous miscarriages (2%). The main modes of ascertainment were a previous child with an unbalanced karyotype (48%), congenital abnormalities at ultrasound examination (20%), and advanced maternal age (9%). The remaining cases had a different mode of ascertainment.


CONCLUSIONS
Inherited unbalanced structural chromosome abnormalities detected at prenatal chromosome analysis are rarely ascertained through two or more miscarriages.
Franssen
M T M
MT
Centre for Reproductive Medicine, Department of Obstetrics and Gynaecology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. m.t.franssen@amc.uva.nl
Korevaar
J C
JC
Tjoa
W M
WM
Leschot
N J
NJ
Bossuyt
P M M
PM
Knegt
A C
AC
Suykerbuyk
R F
RF
Hochstenbach
R
R
van der Veen
F
F
Goddijn
M
M
D000026:Abortion, Habitual / Q000235:genetics*; D005260:Female; D005820:Genetic Testing; D006801:Humans; D009426:Netherlands; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012189:Retrospective Studies; D014178:Translocation, Genetic / Q000235:genetics*