Fluorescence in situ hybridization for the detection of aneuploidy from archived fetal cells.

Abstract

In perinatal settings, fluorescence in situ hybridization has the potential to provide specific chromosome evaluation when full karyotype analysis is not possible because there are no dividing cells. Based on clinical features, cases of fetal and neonatal demise were selected for evaluation with chromosome-specific probes. Sources of nondividing cells included deparaffinated tissue sections, disaggregated tissue biopsies, and archived, Giemsa-stained slides. Diagnostic information was obtained by fluorescence in situ hybridization in three settings: 1) postmortem trisomy 21 identification from paraffin sections following unsuccessful tissue culture, 2) postmortem trisomy 18 confirmation in disaggregated cells from macerated fetal tissues, and 3) retrospective documentation of a cryptic deletion (22q-) in archived metaphase spreads. We encourage familiarity by obstetricians with fluorescence in situ hybridization for chromosomal assessment using archived fetal material.