De novo balanced chromosome rearrangements in prenatal diagnosis.
OBJECTIVE
We surveyed the datasheets of 29 laboratories concerning prenatal diagnosis of de novo apparently balanced chromosome rearrangements to assess the involvement of specific chromosomes, the breakpoints distribution and the impact on the pregnancy outcome.


METHODS
By means of a questionnaire, data on 269.371 analyses performed from 1983 to 2006 on amniotic fluid, chorionic villus and fetal blood samples were collected.


RESULTS
A total of 246 balanced anomalies were detected at frequencies of 72% for reciprocal translocations, 18% for Robertsonian translocations, 7% for inversions and 3% for complex chromosome rearrangements. The total frequencies of balanced rearrangements were 0.09%, 0.08% and 0.05% on amniotic fluid, chorionic villus and fetal blood samples.


CONCLUSIONS
A preferential involvement of chromosomes 22, 7, 21, 3, 9 and 11 and a less involvement of chromosomes X, 19, 12, 6 and 1 was observed. A nonrandom distribution of the breakpoints across chromosomes was noticed. Association in the location of recurrent breakpoints and fragile sites was observed for chromosomes 11, 7, 10 and 22, while it was not recorded for chromosome 3. The rate of pregnancy termination was about 20%, with frequencies decreasing from complex chromosomal rearrangements (33%), reciprocal translocations (24%) to inversions (11%) and Robertsonian translocations (3%).
Giardino
Daniela
D
Lab Citogenetica Medica e Genetica Molecolare, IRCCS Ist. Auxologico Italiano, Milano, Italy. giardino@auxologico.it
Corti
Cecilia
C
Ballarati
Lucia
L
Colombo
Daniela
D
Sala
Elena
E
Villa
Nicoletta
N
Piombo
Giuseppe
G
Pierluigi
Mauro
M
Faravelli
Francesca
F
Guerneri
Silvana
S
Coviello
Domenico
D
Lalatta
Faustina
F
Cavallari
Ugo
U
Bellotti
Daniela
D
Barlati
Sergio
S
Croci
Gianfranco
G
Franchi
Fabrizia
F
Savin
Elisa
E
Nocera
Gianfranco
G
Amico
Francesco Paolo
FP
Granata
Paola
P
Casalone
Rosario
R
Nutini
Lucia
L
Lisi
Ermanna
E
Torricelli
Francesca
F
Giussani
Ursula
U
Facchinetti
Barbara
B
Guanti
Ginevra
G
Di Giacomo
Marilena
M
Susca
Francesco Paolo
FP
Pecile
Vanna
V
Romitti
Lorenza
L
Cardarelli
Laura
L
Racalbuto
Erika
E
Police
Maria Adalgisa
MA
Chiodo
Francamaria
F
Rodeschini
Ornella
O
Falcone
Patrizia
P
Donti
Emilio
E
Grimoldi
Maria Grazia
MG
Martinoli
Emanuela
E
Stioui
Sabine
S
Caufin
Daniele
D
Lauricella
Salvatrice Antonia
SA
Tanzariello
Salvatrice Antonella
SA
Voglino
Gianfranco
G
Lenzini
Elisabetta
E
Besozzi
Marco
M
Larizza
Lidia
L
Dalprà
Leda
L
D000653:Amniotic Fluid; D015193:Chorionic Villi Sampling; D002869:Chromosome Aberrations; D025063:Chromosome Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D003625:Data Collection; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D007621:Karyotyping; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*