Rapid prenatal diagnosis in translocation carriers by interphase FISH with chromosome‐specific subtelomere probes

Abstract

Interphase fluorescence in situ hybridization (FISH) analysis can provide rapid preliminary analysis of chromosome aneuploidy from direct amniocyte and chorionic villus sample (CVS) preparations. Typically, interphase FISH is used in screening for numerical abnormalities of chromosomes X, Y, 13, 18, and 21. More recently, FISH probe sets became available for the subtelomeric region of each chromosome, allowing screening for terminal chromosome rearrangements. The purpose of the current study was to evaluate the use of dual-color interphase FISH analysis with chromosome-specific subtelomere probes for rapid prenatal diagnosis in 14 pregnancies from 12 different translocation carriers. Interphase FISH analysis was performed on direct CVS or amniocyte preparations from 12 reciprocal translocation and two Robertsonian translocation pregnancies with the appropriate chromosome-specific subtelomere probes for each chromosome involved in the translocation. Analysis of the interphase FISH probe signals predicted balanced or normal segregants in each case, thus rapidly excluding a chromosomally unbalanced segregant. Subsequent metaphase analysis showed normal karyotypes in seven fetuses and balanced translocations in the remaining seven. This series illustrates the utility of interphase FISH analysis with chromosome-specific subtelomere probes for rapid prenatal diagnosis in cases of parental reciprocal translocations and Robertsonian translocations.

Early and Rapid Prenatal Diagnosis of Monosomy 2q36.1 in Trophoblast Cells

“…Thus, in this case FISH was mandatory for an accurate prenatal diagnosis. Interphase FISH with specifi c probes has been recently used for a rapid prenatal diagnosis in carriers of reciprocal and Robertsonian translocations [5,6] . In our case, we have developed chromosomal probes to detect the unbalanced segregations associated to the insertion of the band 2q36.1 into the long arm of one chromosome 10 in interphase cells.…”

“…Interphase FISH has been applied for a rapid cytogenetic analysis of embryos from translocation carriers in preimplantation genetic diagnosis [3] . This strategy has been used recently for rapid prenatal diagnosis from direct amniocyte and CVS preparations in the foetuses of balanced translocation carrier parents [4][5][6] .…”