Abstract
Chromosome aberrations (CA) are associated with several genetic heredity diseases. Of concerns, prenatal diagnosis or cytogenetic screening was administered to determine if there are chromosome abnormalities and genetic diseases in a fetus or embryo. However, conventional G-banding technique which is generally applied in CA detection has limit on exploit of copy number variants (CNVs) due to low resolution and tedious multiple processes. Instead, array comparative genomic hybridization (aCGH) technology enabling incremented high-resolution can be considered as an alternative approach for improving prenatal diagnosis. In this study, our aCGH (coverage of SNP tag and CNV regions) was used to identify copy number variations from genomic DNA in human amniotic cell specimens. The aCGH results revealed various karyotypes of CNVs including loss, homozygous loss, gain, high copy gain, and copy neutral LOH whereas using conventional G-banding only one benign cytogenetic CNV was observed in one case study. The aCGH was compatible to define small-scale chromosomal imbalances segment that were undetectable risk segment by G-banding. In contrast, abnormal G-banded karyotypes as balanced rearrangements were hidden from detection by aCGH analysis. The aCGH also provides detailed database of copy number variant regions (CNVRs) in each chromosome. Interestingly, CNVRs containing important genes (ACADM, PPM1B, UGT2B17 and ZDHHC11) were discovered from our data, in which their defects or mutations have been reportedly to be involved in certain genetic heritable diseases and/or syndromes. Gathering together, our detailed CNVs and CNVR via aCGH of amniotic cells might be meaningful database to improve strategy in disease-specific genotoxicity researches.
