Practical Applications of Chromosomal Microarray in Prenatal Diagnosis

Abstract G-banded karyotyping is the most common approach for the detection of genomic alterations. However, this is unable to detect genomic changes of less than 5 Mb. The ability of fluorescence in situ hybridization (FISH) to detect cryptic chromosomal rearrangements exceeds the resolution of routine karyotype. However, conventional FISH is for targeted regions only, whereas the chromosomal microarray is a whole-genome copy number evaluation technique with a resolution of 10 to 20 kb. In this article, we discuss the application of chromosomal microarray 750 K to 384 consecutive prenatal diagnosis cases. Overall diagnostic yield is 15.36%, and chromosomal microarray accounts for a 3.6% additional detection rate. We suggest applying this technique in routine prenatal diagnosis as a first-tier test in prenatal diagnosis along with a backup culture in all cases.