[O-6] VALIDATION OF MICROARRAY CGH FOR PGD BY FISH REANALYSIS.

S. Munne, C. Gutierrez-Mateo, J. F. Sanchez-Garcia, K. Ketterson, R. Prates, D. Kenigsberg Reprogenetics, Livingston, NJ; Long Island IVF, Melville, NY

OBJECTIVE: Comparative genome hybridization (CGH) is successfully applied to trophectoderm biopsy, but it is not compatible with a fresh embryo transfer. Array CGH (aCGH) result turnaround is 24 hrs. We aimed to determine the error rate using aCGH on single cells compared to FISH and what percentage of abnormal embryos would be detected by FISH compared to aCGH.
DESIGN: Embryos donated for research (avg. maternal age 32.7) had one cell biopsied on day 3 and analyzed in 24hrs by aCGH. Each remaining embryo was fixed and analyzed by FISH.
MATERIALS AND METHODS: Single day 3 cells were biopsied, amplified, fluorescently labeled and hybridized onto BlueGnome 24sure BAC arrays. The remaining embryos were fixed and analyzed by 12 probe FISH and reanalyzed in a fourth hybridization for chromosomes found to be abnormal by aCGH.
RESULTS: Six out of 55 biopsied embryos did not yield aCGH results (10.9%). Twenty-nine embryos were classified abnormal by aCGH (59%); 15 had single or double aneuploidy events, 10 were chaotic (3-9 chromosomes affected) and 4 had structural abnormalities. Twenty embryos were classified as normal. One embryo classified by aCGH as normal had a trisomy 22 by FISH (1/20, 5% false negative rate). One embryo diagnosed aneuploid and one as chaotic by aCGH were determined to be normal by FISH (2/29, 7% false positive rate). The total error rate for full chromosome abnormalities was 3/49 (6%). The 9 and 12 FISH probe would have classified 79% and 83%, respectively, of embryos as abnormal.
CONCLUSIONS: aCGH seems to detect about 20% more abnormal embryos than FISH with a 6% error for full chromosome abnormalities. This is similar to the lowest error rate reported by FISH. The technique is not yet reliable for detection of small gains and loses of DNA, and is also partially reliable for gender determination. Technical improvements or more cells analyzed should improve these parameters, but we consider the test to be ready for clinical assessment of aneuploidy.

Monday, October 19, 2009 12:30 PM

Oral Presentation: Prize Paper Candidates