Understanding Genetic Variability: Exploring Copy Number Variants through Non-Invasive Prenatal Testing in European Populations

CNVs are structural alterations in the genome that involve the duplication or deletion of DNA segments, contributing to genetic diversity and playing a crucial role in evolution and development of various diseases and disorders. Massively parallel sequencing (MPS) has revolutionized the field of genetic analysis and contributed significantly to routine clinical diagnosis and screening. It offers a precise method for detecting copy number variations (CNVs) with exceptional accuracy. In this context, non-invasive prenatal test (NIPT) based on the sequencing of cell-free DNA (cfDNA) from pregnant women's plasma using a low coverage whole genome MPS (WGS) approach represents a valuable source for population studies. Here, we analyzed genomic data of 12 732 pregnant women from the Slovak (9 230), Czech (1 583), and Hungarian (1 919) populations. We identified 5 062 CNVs ranging from 200 kbp and described its basic characteristics and differences between the subject populations. Our results suggest that re-analysis of sequencing data from routine WGS assays has the potential to obtain CNVs population frequencies, and may provide valuable information to support classification and interpretation of this type of genetic variation.