Nonivasive prenatal DNA-screening the scope and the prospects of whole-genome sequencing

Abstract

Noninvasive prenatal DNA screening (NIPS) is getting more widespread in clinical practice in Russia and all around the world. The use of shallow whole-genome sequencing for NIPS allows analysis of all chromosome aneuploidies; hence there are large-scale studies only on test performance on common trisomies. This study aimed to analyze the prevalence of «rare» aneuploidies using whole-genome NIPS and pregnancy outcomes in case of a high risk of «rare» aneuploidy. Noninvasive prenatal DNA screening was performed using in house developed protocol. We have analyzed 2061 samples. In 8 cases (0.4%) high-risk of rare trisomy was detected (3 - trisomy 7, 2 - trisomy 8, 1 - trisomy 10, 2 - trisomy 15). We have identified two cases of a high risk of large copy number variations (CNV). For all of the high-risk cases, we have information about pregnancy outcomes. Thereby whole-genome analysis will enable us to get the additional information and reveal pregnancies in need of further observation or testing. Hence there is not enough data for the estimation of sensitivity and specificity of detection of «rare» aneuploidies.