Purpose: To illustrate the use of bacterial artificial chromosome (BAC) clone panels for molecular cytogenetic analysis of complex chromosome rearrangements (CCRs).
Methods: High resolution cytogenetics followed by fluorescence in situ hybridization (FISH) analysis using chromosome band-specific BAC probes, in addition to commercially available probes.
Results: High resolution cytogenetics in conjunction with FISH using commercially available probes proved inadequate to resolve problems in characterizing a balanced CCR in the mother of a patient who had inherited an unbalanced form of the CCR. Accurate interpretation of the CCR and the unbalanced rearrangement in the patient as trisomy 7p12.2-->p21.3 was accomplished only through use of the BAC clone panel.
Conclusion: Use of BAC clone panels can enhance the power of FISH analysis in defining chromosome rearrangements that cannot be resolved by high resolution chromosome analysis.