In chromosomal microarray analysis, what percentage of normal karyotype fetuses may have pathogenic CNVs?

In chromosomal microarray analysis, it is established that a subset of fetuses with a normal karyotype can still carry pathogenic copy number variants (CNVs). Research indicates that approximately 1% of fetuses that present a normal karyotype upon standard cytogenetic analysis can have clinically significant CNVs detected by chromosomal microarray. Pathogenic CNVs are variations in the number of copies of a particular segment of DNA that can lead to various clinical manifestations, and detecting these through microarray provides valuable information that may not be apparent through traditional karyotyping. The identification of these CNVs may have implications for prenatal counseling and management, highlighting the importance of using advanced molecular techniques in the assessment of fetal anomalies despite a normal karyotype.