Early and rapid prenatal diagnosis of monosomy 2q36.1 in trophoblast cells.
OBJECTIVE
CVS is the earliest procedure for cytogenetic analysis but the quality of metaphases obtained does not allow the characterization of subtle chromosomal anomalies. We report the application interphase fluorescence in situ hybridization for the rapid prenatal diagnosis of a subtle structural chromosome anomaly in trophoblast cells.


RESULTS
The foetus was karyotyped because of a paternal complex chromosomal anomaly 46,XY,inv(2)(q14.3q35),ins(10;2)(q25;q36.1q36.1). Fluorescence in situ hybridization analyses were performed on interphase nuclei and metaphase chromosomes from uncultured chorionic villi using bacterial artificial chromosomes specific for the 2q chromosomal region. Direct conventional cytogenetics showed an apparently normal male karyotype, whereas fluorescence in situ hybridization analysis showed a deletion of the chromosomal region 2q36.1 and a paracentric inversion of the chromosome 2q leading to a partial monosomy 2q36.1.


CONCLUSIONS
This strategy allowed us to offer an early and rapid chromosomal analysis for this couple leading to a better management of the pregnancy. This report demonstrates that interphase fluorescence in situ hybridization can be used in direct CVS for a rapid and early prenatal diagnosis of complex chromosomal rearrangements.
Tachdjian
Gérard
G
Service d'Histologie Embryologie Cytogénétique, Hôpital Antoine Béclère (APHP), Clamart, France. gerard.tachdjian@abc.ap-hop-paris.fr
Aboura
Azzedine
A
Brisset
Sophie
S
Dommergues
Marc
M
Gajdos
Vincent
V
Labrune
Philippe
P
D002675:Child, Preschool; D015193:Chorionic Villi Sampling; D002871:Chromosome Banding; D007446:Chromosome Inversion / Q000235:genetics; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics*; D005260:Female; D017353:Gene Deletion; D005865:Gestational Age; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D009006:Monosomy / Q000175:diagnosis*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D014327:Trophoblasts / Q000648:ultrastructure*