The clinical use of chromosomal microarray analysis in detection of fetal chromosomal rearrangements: a study from China Mainland

Abstract Objectives This study aimed to evaluate the detection rate of chromosomal microarray analysis (CMA) in prenatal fetuses compared with conventional karyotype and to assess the additional diagnostic yields of CMA in groups of different indications. Study Design A total of 217 fetuses were divided into seven groups according to different indications. All cases were tested by both CMA and karyotype. The detection rates of CMA and karyotype were evaluated. The increased value of CMA in each group was also calculated. Results A total of 35 cases were detected to have a pathogenic result by CMA, indicating the overall detection rate of 16.1%. Nine more cases were detected only by CMA, indicating an incremental diagnostic yield of 4.2%. The highest incremental value was observed in fetuses with structural defects (6.6%). In 11 cases with known abnormal chromosome anomalies, CMA revealed additional information over conventional karyotyping in 4 fetuses. Conclusions The present study convincingly demonstrated the efficiency of CMA in detecting feal chromosomal rearrangements. CMA significantly improves the detection rate in fetuses with structural defects and provides helpful information for fetuses with known abnormal chromosomes but without clear diagnosis.