Fetoplacental discrepancy involving structural abnormalities of chromosome 8 detected by prenatal diagnosis |
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Authors: | Dr Anna Soler Aurora Sánchez Ana Carrió Cèlia Badenas Montserrat Milà Antoni Borrell |
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Institution: | 1. Servei de Genètica, CDB, Hospital Clí nic, Barcelona, Spain;2. Departament d'Obstetrí cia i Ginecologia, Hospital Clí nic, Barcelona, Spain |
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Abstract: | We describe the finding of three cell lines involving different structural abnormalities of chromosome 8 detected in a prenatal diagnosis. Chorionic villi sampling (CVS) was performed on a pregnant woman because of advanced maternal age. Semidirect cytogenetic analysis showed a mos46,XX,i(8q)/46,XX,del(8)(p11.2) karyotype, confirmed by fluorescence in situ hybridization (FISH). Amniocentesis was subsequently performed, and the karyotype obtained was 46,XX,dup(8)(p23p11.2). The pregnancy was terminated; pathologic findings included clubfeet, clenched left hand, subcutaneous edema and bilateral hydrocephalus. Molecular studies using chromosome 8 microsatellites performed on parents' blood and fetal tissues revealed a maternal meiotic origin of the inv dup(8p) with deletion of the distal p23 region and duplication of the remaining 8p. We propose a model to explain the cytogenetic findings, which includes a first maternal meiotic error giving rise to a large dicentric isochromosome 8 present in the ovum, a second error in one of the first zygote divisions with misdivision of the dicentric 8 giving rise to a cell line with del(8p) confined to the trophoblast and another cell line with inv dup(8p) confined to the fetal tissue and a third error in the trophoblast giving rise to a further cell line with isochromosome 8q. Copyright © 2003 John Wiley & Sons, Ltd. |
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Keywords: | confined placental mosaicism structural chromosome abnormalities inv dup(8p) prenatal diagnosis |
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