Molecular and cytogenetic characterization of extra-structurally abnormal chromosomes (ESACs) found prenatally: outcome and follow-up

A 40‐year‐old woman underwent amniocentesis at 15.3 weeks of gestation. Chromosome analysis performed using QFQ, DA‐DAPI and CBG banding revealed two de novo extra‐chromosomal markers (ESACs) in 11 of the 16 colonies analysed. Fluorescence in situ hybridization (FISH) showed that both chromosomes came from the Yq11.22.1 region of the Y chromosome. PCR analysis of genes and STS localized on the Y chromosome excluded the Yp presence specifically of the SRY gene, and most of the euchromatic region of Yq. After extensive genetic counselling and considering both laboratory and second‐level ultrasound data, the couple decided to continue the pregnancy. At 37.4 weeks of gestational age, a girl weighing 2750 g was born with an Apgar score of 9/10. A blood sample taken from the umbilical cord showed three cellular lines:mos47,XX, +mar1 ish.der (Y)(wcpY+) [21%]/48,XX, +mar1 ish.der (Y)(wcpY+), +mar2 ish.der (Y)(wcpY+) [41%]/46,XX [38%]. One year after birth, the baby was developing normally and had normal psychomotorial activity. Copyright © 2003 John Wiley & Sons, Ltd.