Prenatal diagnosis by array-comparative genomic hybridization

Array-comparative genomic hybridization (aCGH) was developed as a high-resolution analysis of DNA copy number variations, initially in cancer studies, and subsequently extended to postnatal evaluation of mental retardation and multiple congenital anomalies.

To review the current and potential applications of aCGH in prenatal diagnosis.

The role of aCGH is compared with conventional prenatal diagnostic methods regarding turnaround time, resolution and cost. The challenges and concerns are also discussed.

Array-CGH offers a rapid analysis of the DNA copy number variations with results of a comprehensive genome-wide picture available within 3 days' time, much shorter than the G-banded analysis, which takes at least 2 weeks. In addition, its superior resolution allows detection of submicroscopic microdeletions or microduplications, and a more precise delineation of chromosomal aberrations, leading to improved genotype-phenotype correlations. However, aCGH cannot detect truly balanced chromosomal rearrangements or polypoidy, and may even generate data with unknown significance. Knowing its limitations and with proper counseling of the advantages and shortcomings of aCGH, the authors believe aCGH will become the first-line diagnostic test for management of pregnancy with fetal sonographic anomalies.