Array comparative genomic hybridization analysis in first-trimester spontaneous abortions with 'normal' karyotypes

Array comparative genomic hybridization (array CGH) analysis was conducted in chorionic villous samples from 20 first‐trimester spontaneous abortions with G‐banding normal chromosomes. A microarray, containing 2,173 BAC clones and covering the whole genome with a 1.5‐Mb resolution, was constructed and used in the analysis. Two deletions were identified: a 1.4‐Mb deletion at 3p26.2‐p26.3 and a 13.7‐Mb deletion at 13q32.3‐qter. Reexamination of chromosome preparations from the sample with the 13.7‐Mb deletion documented a mixture of cells with the 13q‐ chromosome and those with 46,XX chromosomes, the latter of which are likely to have been derived from contaminating decidual cells. This left the 1.4‐Mb 3p deletion as the only instance with submicroscopic imbalance detected, giving a frequency of 1 in 19 (5%) G‐banding normal abortions. © 2006 Wiley‐Liss, Inc.